Corrosion Testsand Standards:Application andInterpretation Second Edition

Robert Baboian, Editor

Section EditorsRobert BaboianSheldon w. Dean, Jr.Harvey P. HackEdward L. HibnerJohn R. Scully

ASTM Stock Number: MNL20-2nd

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Library of Congress Cataloging-in-Publication Data

COITOsion tests and standards : application and interpretation IRobert Baboian, editor ; section editors, Robert Baboian[et al.].-2nd ed.

p. cm.-(ASTM manual series; MNL 20)ASTM Stock Number: MNL20-2ndISBN 0-8031-2098-21. Corrosion and anti-corrosives-Testing. 1. Baboian, Robert.n. Series.

TA462.C666 2005620.1' 1223---dc22

2004025972

Copyright 2005 ASTM International, West Conshohocken,PA. All rights reserved. This material may not be reproducedor copied, in whole or in part, in any printed, mechanical,electronic, film, or other distribution and storage media,without the written consent of the publisher.

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Printed in Baltimore, MDJanuary 2005

THE EDnORS

SECTION EDITORS

ROBERT BABOIAN,EditorRobert Baboian is a corrosion consultant with RBCorrosion Service. He received bis B.S. degree in chem-istry from Suffolk University in 1959 and his Ph.D. inphysical chemistry from Renssalaer Polytechnic Insti-tute in 1964. He did postdoctoral research at the Uni-versity of Tomnto in 1964 and subsequentIy received afaculty appointment to Senior Research Associate in1965. He joined the Materials and Controls Group ofTexas Instruments, Inc. in 1966, where he establishedthe Electrochemical and Corrosion Laboratory. Heretired from Texas Instruments in December 1996 asPrincipal Fellow and Head of the Electrochemical andCorrosion Laboratory. The Principal Fellow position atTI is the company's bighest honor for scientific andtechnical acbievement. He is an ASTM Honorary Mem-ber, a Fellow of ASTM, NACE, and SAE, and was a ForoFoundation Postdoctoral Fellow in 1964.Dr. Baboian has been dedicated to the research and development of corrosion resistant mate-rials and devices, environmental effects on materials, and the use of e1ectrochemical tech-niques in corrosion testing for almost 40 years. He holds 15 U.S. patents, is the editor of 13books, and has authored over 170 technical publications. He has served on a number of Gov-ernment and Academic Committees and has lectured throughout the world, and his serviceswere donated by TI to the National Park Service as a corrosion consultant on the Statue 01Liberty restoration programo RecentIy, he has researched the sinking of the Titanic and hasproposed theories on corrosion mechanisms causing the failure.Recognized far his active involvement in the technical cornmunity, Dr. Baboian has received theCavanaugh Award and the Award of Merit from ASTM, the ASTM Dudley Award for publica-tions, the ASTM LaQue Award for outstanding contributions to corrosion testing and evaluation,the Speller Award for outstanding contributions in corrosion engineering, and the T. J. HuIlAward for publications from NACE, the Seience and Technology Award of the Suga WeatheringTechnology Foundation in Japan, the Vittorio de Nora Award from the Electrochemical Society,the Francis L. LaQue Award for contributions to marine corrosion and prevention from thelaQue Center Sea Horse Institute, and the National Materials Advancement Award from theFederation of Materials Societies. He has served on the Executive Committee and the Board ofDirectors of ASTM and NACE and was the Chairman of the ASTM Board of Directors in 1987.He also has chaired ASTM Committee G-1 on Corrosion of Metals, the SAE Automotive CoITO-sion and Protection Committee, and the NACE Research Committee.

EDWARD L. HIBNERis a Sen-ior Metallurgist and Code Manager at SpecialMetals Corporation, forrnerJy Inca Alloys Interna-tional, in Huntington, West Virginia. He receivedbis B.S. in Chemistry from Marshall Universityand in Metallurgy from the University of Cincin-nati. He is the recipient of the ASTM Awardof Merit, the ASTM Committee G-l Francis L.LaQue Memorial Award, the ASTM CommitteeG-l Certificate of Appreciation, and the NACEFelJow Award, and is currently Viee-Chairmanand the Editorial Review Chairman of ASTMCornmittee G-l on Corrosion of Metals. He hasserved as Chairman and as Trustee of the WestVirginia Section of NACE International and iscurrently serving on the NACE MR0175/ ISO15156 Maintenance Panel. He has extensive ex-perience in alloy development for chemical proc-ess, flue gas desulfurization. marine, and oil fieldapplications. He has written wide1y on materialsapplications and corrosion topics in these fieldsand has four patents and 60 publications. In addi-tion to ASTM Intemational, he is a member of theIntemational Desalination Association, the Soci-ety for Petroleum Engineers, ASME Intemational,SAE International, NACE International, and theNaval Subrnarine League.

JHN R. SCULLy received bis B.S.,M.S., and Ph.D. in Materials Science and Engi-neering from Johns Hopkins University. Whilepursuing bis Ph.D., he worked at David TaylorNaval Ship R&D Center in Annapolis, Maryland inthe Marine Corrosion Branch. He then joinedSandia National Laboratory after a terrn as a Visit-ing Scientist at AT&T Bell Laboratories. In 1990,he joined the faculty of the Department of Materi-als Science and Engineering at the University ofVirginia and is a fuIl professor and co-directs theCenter for Electroehemical Science and Engineer-ing. Professor Scully received the 1985 A. B.Campbell Young Author Award from NACE. Hehas also been selected as a National Science Foun-dation Young Investigator, and has received the H.H. Uhlig Award from NACE and the William BlumAward from the Electrochemical Society. ProfessorScully has published oVer 1()() technical papers andedited severa! books on corrosion.

HARVEY P. HACKDr. Hackis anAdvisory Engineer for Northrop Grurnman Carpo-ration, where he does materials selection and cor-rosion control for underwater vebicles and systemsfor the Department of Defense. He received bis B.S.and M.S. from Carnegie-Mellon University, and bisph.D. in Metallurgy from The Pennsylvania StateUniversity. He is the recipient of the ASTM Interna-tional Award of Merit, and is past Chainnan of theBoard of Directors of ASTM International. Dr. Hackhas received the Distinguished Service Award fromNACE Intemational, the Francis L. LaQue Memo-rial Award from ASTM Committee G-l on Corro-sion of Metals, and the Francis L. LaQue Awardfrom the Sea Horse Institute. He is a NACE Corro-sion Specialist, Cathodic Protection Specialist, andCoatings Inspector, a FelJow of NACE Interna-tional, ASTM International, lhe Washington Acad-erny of Sciences, and the Institute of Corrosion inthe United Kingdom, and is a Registered profes-sional Engineer in Maryland. Dr. Hack is the Asso-ciate Editor for the Materials Perfonnance andCharacterization section of the Journal of ASTMInternationaI (JAlJ. is on the Materials AdvisoryBoard for the National Air and Space Museum ofthe Smithsonian Institution, and is a past Presidentof the Council of Engineering and Scientific SpecialtyBoards. Dr. Hack has approximate1y 70 publicationsand is the author, editor, or major con-tributar to fivebooks. He is the author of a regular colurnn on corro-sion in Underwater Magazine.

iii

SHELDN W. DEAN, JR.is eurrently the President of Dean CorrosionTechnology, Inc., a consulting finn in Allentown,Pennsylvania that provides expert advice onmatters involving corrosion of metals. He is alsoEditor in Chief of the Journal of ASTM Interna-tional. He received bis A.B. from MiddleburyColJege and bis B.S. and Se.D. from the Massa-chusetts Institute of Technology. He has receivedthe ASTM Award of Merit, the Charles B. DudleyAward, the Sam Tour Award, the Francis L.LaQue Memorial Award, the ASTM Committeeon Publications Award for ExcelJence, the ASTMCommittee G-l Certificate of Appreciation, theNACE Frank Newman Speller Award, the NACEFellow Honor, and was named a FelJow of theAmerican Institute of Chemical Engineers andthe Materials Technology Institute. He has servedas chairman of ASTM Committee G-l fur fouryears. He also served on and chaired the ASTMComrnittee on Publications and the ASTM Boardof Directors, and chaired the Finance and AuditCommittee. He has also served on and chairedthe Board of Directors of the Materials Technol-ogy Institute. He has 12 U.S. patents, 96 publica-tions. and has co-edited eight books.

Reviewers

Dinesh AgarwalVinod AgarwalaHira AhluwaliaPaulAimoneGeorge AndersenFrank AnsuiniPeter AultDenise AylorRobert BaboianBrian BakerMilan BartosNeal BerkeThomas BrittonC. Sean BrossiaRudolph G. BuchheitKenneth BudinskiJames BushmanPaul BrewerJulie BrownKirkBundyGustavo CragnolinoLee CraigSheldon DeanTerry DeBoldStephen DexterGeorge DiBariJeffrey DidasCharles DillonMarcia DomackGeorge DownsDave DuquetteK. Daniel EfirdNathan EisingerPeter ElliottDavid EnosEd EscalanteJohn FitzgeraldAnna FrakerGerald Frankel

Jim GossettRichard GranataHarveyHackWilliam HarttGardner HaynesGeorge HaysEdward HibnerStanley HirozawaF. Galen HodgeAlfred HopkinsWilliam JarosinskiJames JenkinsDenny JonesRussell JonesRobert KainMike KatcherRobert KellyGerhardus KochSimeon KrumbeinPaul LabineHerbert LawsonJason LeeDaomingLiBrenda LittleDaryl LittleFrank LutzeFlorian MansfeldCharles MarshJames MartinPeter MayerJoseph MenkeJean-Marc MeyerHarold MichelsTom MillsJames MoranPatrick MorrisMaxMoskalJim MyersJames Noel

iv

Sankara PapavinasamFrederick PettitBopinder PhullRobert PuyearDavid ReiserPierre RobergePaul RothmanKen Sto JohnAlberto SaguesStuart SaundersJohn SchemelGeorge SchickJohn ScullyK. Anthony SelbyDavid ShiflerTetyana ShmyrevaDavid SilvermanJ. Douglas SindairRayrnund SingletonJoseph SlusserGaylord SmithJohn SnodgrassDonald SnyderNarasi SridharSridhar SrinivasanAnthony StavrosT. J. SummersonWilliam TillisHerbert TownsendHector VidelaYash VirmaniGeorge WaidRobertWeiPaul WhitcraftJan WrightGeorge YoungWalter y oung

Foreword

THE REVISED PUBLICATION, Corrosion Tests and Standards: Application and Interpretation,is sponsored by ASTM Committee G1 on Corrosion of Metals and edited by RobertBaboian, RB Corrosion Service. Section editors include Robert Baboian, SheldonW. Dean, Dean Corrosion Technology, Harvey P. Hack, Northrup Grumman Corpora-tion, Edward Hibner, Special Metals Corporation, and John R. Scully, University ofVirginia. This is the second edition of Manual 20 in the ASTM Manual series.

Preface

CORROSION CONTINUES to be a problem of worldwide importance. The second editionof this manual has been prepared and published to address this form of degradation.Corrosion is afien neglected, but it seriously impacts our economy, jeopardizes hu-man health and safety, and impedes technological progress. The most important fac-tors in addressing corrosion and its control are: (1) recognizing and understandingthe mechanisms, (2) developing solutions to the problems, and (3) implementingthose solutions. Corrosion tests and standards are very significant in addressing eachof these factors. Therefore, this manual includes guidelines for recognizing types ofcorrosion as well as fundamentals of testing and provides the tools required for mak-ing calculations, interpretations, and correlations. It serves as a source book of proce-dures, equipment, and standards used in testing.

The editor and section editors have coordinated the revision and update of thisbook so that most recent technologies are included in each section. In most cases, theoriginal authors of chapters have made the revisions. In sorne cases, new authorsneeded to be chosen, or the editors performed that task. Users of the manual will findthat it is an invaluable and instructive tool, as well as a source book on how to con-duct corrosion tests, interpret results, and use standards.

The second edition of the manual is the result of a massive effort of planning, writ-ing, reviewing, editing, production, and marketing. It would not have been possiblewithout the outstanding efforts of the ASTM staff and the valuable and competentwork of the editors and over 400 experts in the field that donated their time as au-thors and reviewers. They represent industrial, educational, and government organi-zations, and their contributions are greatly appreciated.

Robert BaboianEditor

v

Contents

Introduction

1: GENERAL INFORMATION-R.Baboan, Section Editor

Unified Numbering System for Metals and AlloysExamples of Common Names of Selected UNS AlloysStandard Terminology Relating to Corrosion and Corrosion TestingGlossary of Corrosion-Related AcronymsStandard Abbreviations and Unit SymbolsIntemational System of Units (SI)General Conversion FactorsCondensed Metric Practice Guide for CorrosionMultiplication Factors (SI Prefixes)Corrosion Rate Conversion FactorsCorrosion Rate Calculation (from Mass Loss)Corrosion Rate Conversion FactorsDensitieslK Factors for AlloysOvervoltage ValuesReference Potentials and Conversion TableEquivalent Weight Values for Metals and AlloysConstants Used in Faraday's EquationPhysical Properties of Gases and LiquidsPhysical Properties of ElementsDensities of Metals and AlloysDensity of MaterialsThermal Expansion Coefficients for AlloysPhysical Properties of WaterDew Point of Moist AirChemical Cleaning Procedures for Removal of Corrosion ProductsElectrolytic Cleaning Procedures for Removal of Corrosion products

11: TESTING AND EVALUATION-R.Baboian, Section Editor

Chapter l-Planning and Design of TestsStephen D. Cramer and Barnie P. Iones

Chapter 2-Types of DataDavid C. Silverman

Chapter 3-Metallographic AnaIysisRichard L. Colwell

v

1

457

1214171820222223242526272830313233353637384346

49

59

66

vili CORROS/ON TESTS AND STANDARDS MANUAL

Chapter4-SurlaceAnmys~Alfred G. Hopkins

Chapter 5-Statisticm Treatment of Data, Data Interpretation, and ReliabilityFred H. Haynie

Chapter 6--Computer Based Data Organization and Computer ApplicationsPierre R. Roberge

III: TYPES OF TESTS-H. P. Hack, Section Editor

Chapter 7-Electrochemicm TestsJohn R. Scully

Chapter 8-Cabinet TestsCynthia L. Meade

Chapter 9-lmmersion TestingRichard A. Corbett

Chapter 10-High-Temperature and High-Pressure Corrosion TestingRussell D. Kane

Chapter ll-AtmosphericSheldon W. Dean, Jr.

Chapter 12-SeawaterJames F. Jenkins

Chapter 13-FreshwaterWalter T. Young and Philippa Fairer

Chapter 14-SoilsEdward Escalante

Chapter 15-lndustrlm ApplicationsAllan Perkins

Chapter 16--High-TemperatureGaylord D. Smith

IV: TESTING FOR CORROSION TYPE~. R. Scully, Section Editor

Chapter 17-Uniform CorrosionJames A. Ellor and John Repp

Chapter 18-PittingRobert G. Kelly

Chapter 19-Crevice CorrosionNarasi Sridhar, Darrell S. Dunn, C. S. Brossia, Gustavo A. Cragnolino, and Jeffery R. Kearns

Chapter 20-GmvanicHarvey P. Hack

Chapter 21-IntergranularMichael A. Streicher

76

83

89

107

131

139

147

159

170

175

181

187

194

205

211

221

233

244

Chapter 22-ExfoliationDonald O. Sprowls; revised by Kevin R. Cooper

Chapter 23-Erosion, Cavitation, and FrettingW. A. Glaeser

Chapter24--DealloyingAnn Chidester Van Orden

Chapter 25-Environmental Cracking-Stress CorrosionW. Bany Lisagor

Chapter 26-Environmental Cracking-Corrosion FatigueRichard P. Gangloff

Chapter 27-Hydrogen DamageC. G. Interrante and L. Raymond

V: TESTlNG IN ENVIRONMENTS-H. P. Hcu:k, Section Editor

Chapter 28-outdoor AtmospheresHerbert H. Lawson

Chapter 29-Indoor AtmospheresJ. D. Sinclair

Chapter 3O-SeawaterDavid A. Shifler and Denise M. Aylor

Chapter 31-FreshwaterWalter T. Young and Philippa Fairer

Chapter 32-SoilsLucien Veleva

Chapter 33-ConcreteNeal S. Berke

Chapter 34--Industrlal WatersA. S. Krisher

Chapter 35-Industrlal ChemicalsRobert B. Puyear

Chapter 36--PetroleumK. Daniel Efird

Chapter 37-High-Temperature GasesGaylord D. Smith and Brian A. Baker

Chapter 38-0rganic LiquidsC. S. Brossia and D. A. Shifler

Chapter 39-Molten SaltsF. S. Pettit

Chapter 40-Liquid MetalsChris Bagnall, Peter F. Tortorelli, Steven J. Pawel, Jack H. DeVan, and Steven L. Schrock

CONTENTS ix

266

273

278

289

302

322

343

349

362

380

387

405

413

418

425

434

448

457

465

x CORROSION TESTS AND STANDARDS MANUAL

Chapter 41-Corrosion InhibitorsRudolfH. Hausler

Chapter 42-Corrosion Testing in In Vivo EnvironmentsK. l. Bundy

Chapter 43-Microbiological EffectsStephen C. Dexter

VI: MATERIALS TESTING-E. L. Hibner, Section EditorChapter 44-Zinc

Frank E. Goodwin and Safaa l. Alhassan

Chapter 45-Lead (and Alloys)Safaa l. Alhassan and Frank E. Goodwin

Chapter 46-Magnesium (and Alloys)lames E. Hillis

Chapter 47-Aluminum (and Alloys)Bernard W. Lifka

Chapter 48-SteelsM. E. Komp, D. L. lordan, and R. Baboian

Chapter 49-Copper (and Alloys)Arthur Cohen

Chapter 5O-Nickel (and Alloys)Edward L. Hibner

Chapter 51-Stainless Steelslames W. Martin

Chapter 52-Cobalt-Base AlloysP. Crook

Chapter 53-TitaniumRonald W. Schutz

Chapter 54-Zirconium and HafniumTe-Un Yau

Chapter 55-Tantalum and Niobium AlloysE. B. Hinshaw and K. D. Moser

Chapter 56-Metallic Coatings on SteelT. C. Simpson and H. E. Townsend

Chapter 57-Nonmetallic CoatingsRichard D. Granata

Chapter 58-Metal-Matrix CompositesL. H. Hihara

Chapter 59-ElectrodepositsT. P. Moffat

480

500

509

525

531

537

547

558

565

580

585

591

598

613

617

620

632

637

656

Chapter 6o-Powder Metallurgy (P/M) MaterialsErhard Kiar and Prasan K. Samal

VII: TESTING IN INDUSTRIES-S. W. Dean, fr., Section EditorChapter 61-Automotive

Robert Baboian

Chapter 62-Commercial AircrafiA. A. Adjorlolo and J. A. Marceau

Chapter 63-Military Aircraft and Associated EquipmentEarl C. Groshart

Chapter 64--PipelinePaul S. Rothman and Walter T. Young

Chapter 65-Highways, Tunnels, and BridgesJames B. Bushman and Victor Chaker

Chapter 66--Marine-Piers and DocksJames F. Jenkins

Chapter 67-Electric PowerP. Mayer and A. D. Pellgrini

Chapter 68-Nuclear PowerGeorge J. Licina

Chapter 69-Steam GenerationOtakar Jonas

Chapter 7o-Flue Gas DesulfurizationHarvey S. Rosenberg and Eldon R. Dille

Chapter 7l-ElectronicsRobert Baboian

Chapter 72-TelecommunicationsGeorge Schick

Chapter 73-Metals ProcessingTerry A. DeBold

Chapter 74--Chemical ProcessingBert Moniz and shi Hua Zhang

Chapter 75-Pulp and PaperAngela Wensley

Chapter 76--Petroleum Production and RefiningR. N. Tuttle

Chapter 77-Food and BeverageW. E. Clayton and B. Tholke

Chapter 78-Water Handling SystemsBennett P. Boffardi

CONTENTS xi

664

673

687

693

696

706

716

722

727

738

746

754

762

769

779

795

812

822

826

xii CORROSION TESTS AND STANDARDS MANUAL

Chapter 79-Medical and DentalAnna C. Fraker

Chapter 80--PharmaceuticalDavid F. Jensen

VIII: CORROSION-RELATED STANDARDS-H.P. Hack and R. Baboian, Section Editors

LIST OF CORROSION-RELATED STANDARDS

Author Index

Subject Index

834

846

851

865

867

MNL20-2ND-EB/Jan. 2005

Introduction

ASTM'S AWARD-WINNING Manual 20 has been revised andupdated to include current and state-of-the-art technologiesin corrosion testing and standardization. The editors of thismanual have many years of experience in this field and arewell qualified in leading the task to provide state-of-the-artinformation on this subject for corrosion scientists andtechnologists throughout the world. The work of 80 highlyqualified chapter authors and numerous reviewers hasresulted in a revised, expanded, and updated Manual 20 onCorrosion Tests and Standards, Application and Interpre-tation.

Corrosion is the chemical or electrochemieal reaction be-tween a material, usually a metal, and its environment thatproduces a deterioration of the material and its properties.The direct cost of corrosion in countries throughout theworld is estimated to be between 3 % and 4 % of the grossdomestie product of each country. For example, that cost inthe United States was estimated to be $276 billion annually,for recent years. It was determined that a significant por-tion of these costs could be avoided through the more effec-tive use of existing technologies and the use of soundcorrosion management techniques. This manual is a keyresource in addressing both of these subjects.

Corrosion testing is one of the most important aspects ofcorrosion control because it is used to advance technologyand to determine the most effective and economieal meansto achieve acceptable performance. A large number of fac-tors affect corrosion behavior so that there is no universalcorrosion test. ASTM and other organizations such as NACE,ISO, and others have standardized many tests and practiees.However, industry, govemment, and academie laboratoriessometimes utilize in-house tests. Thus, this Manual providesa valuable resource describing and listing a large number oftests ranging from highly accelerated laboratory tests tofield serviee trials.

Since standards are universally recognized as an importanttool in effective corrosion control management, this Manualnot only provides information required to find and useproper standards in specific applications, it also includes aCD with almost 200 of the most widely used ASTM andNACE corrosion standards. All of the chapter authors haveincluded important standards specific to their topie and theManual includes lists of standards according to subject, ofwhieh the most important are included in the CD.

The revised Manual is organized into eight sections.Section I on General Infonnation (R. Baboian, Section

Editor) provides tools necessary for the corrosionist to define,1

interpret, and evaluate the technology. This section is greatlyexpanded and includes a unified numbering system for met-als and alloys and their common names, standards terminol-ogy, a glossary of tenns and acronyrns, abbreviations andunits syrnbols, Intemational System of Units and matrixguide, general conversion tables, corrosion rate calculationsand all necessary conversion factors, chemieal and physiealproperties of materials, properties of water and moist air,chemieal and electrolytie cleaning procedures for corrosionproducts, physieal properties of gases, liquids and elements,and densities of metals and alloys.

Section II on Testing and Evaluation (R. Baboian,Section Editor) is designed to provide important informa-tion on planning and design of tests and interpretation ofresults. This topie provides a foundation for corrosion test-ing and the Use of corrosion standards. It includes chapterson planning and design of tests, types of corrosion data,metallographic and surface analysis, statistieal treatment ofdata and data computerization and computer applications.

Section III covers Types of Tests (H. Hack, Section Edi-tor) including laboratory-accelerated tests, field tests, andserviee tests. The chapters in this section provide basieprincipIes, describe test techniques and specific considera-tions such as specimen preparation, test duration andacceleration factors, and cite pertinent standards. Chaptersincluded under laboratory tests are electrochemieal, cabi-net, immersion, high temperature, and high pressure. FieldTests chapters include atmospherie exposure, seawater,fresh water, and soil. Under serviee tests are industrialapplieations and high temperature environments.

Section IV on Testing for Corrosion Types (J. Scully,Section Editor) describes the major fonns of corrosion, howto recognize them and factors of influence. Each chapterincludes an overview of basie principIes and also descrip-tions of test techniques, methods of evaluation of test re-sults, and standards used for testing. Subjects included areuniform, pitting, crevice, galvanic, intergranular, exfoliation,erosion, cavitation, fretting, dealloying, stress corrosion, cor-rosion fatigue and hydrogen damage.

Section V on Testing in Environments (H. Hack, SectionEditor) includes chapters on outdoor and indoor atmos-pheres, seawater, fresh water, soils, concrete, industrial wa-ters, industrial chemieal, petroleum, high-temperature gases,organie liquids, molten salts, liquid metals, corrosion inhibi-tors, in-vivo, and mierobiologieal effects. Each chapter pro-vides a descriptive overview of the environment and factorsand variables affecting corrosion rates and mechanisms,

rnnvrlahtcJ 7nn':;:hv A~TM Tntprn~t'\n~l uruur ~ ~trn nrtT

2 CORROS/ON TESTS AND STANDARDS MANUAL

unique characteristics of testing, descriptions of appropriatelaboratory and field tests and lists of standards used for cor-rosion testing in these environments.

Section VI is on Materials Testing (E. Hibner, SectionEditor). This section provides overviews of important testsused in evaluating the cOITosion behavior of metals and alloys.In addition, this testing information provides the means forthe development of new and improved cOITosion resistantmaterials. Each chapter ineludes a discussion of the nature ofthe material, such as the effect of composition, alloying, met-allurgical treatments, microstructure, surface effects andnatural films on the coITosion behavior. The chapter also in-eludes descriptions of tests used for specific types of coITosionfor the metals and alloys, methods of evaluation of COITosiondamage and standards used for corrosion testing of the vari-ous materials. The chapters are zinc, lead (and alloys), alumi-num (and alloys), steels, copper (and alloys), nickel (andalloys), stainless steels, cobalt-base alloys, titanium, zirconiumand hafuium, tantalum and niobum alloys, metallic coatingson steel, nonmetallic coatings, metal matrix composites, elec-trodeposits, and powder metallurgy materials.

Section VII on Testing in Industries (S. Dean, SectionEditor) provides an overview of cOITosion testing unique toeach industry and how these tests are used to address cor-rosion problems. Ineluded are descriptions of environmentsencountered and materials used in specific industries. Testmethods for COITosion control and evaluation are describedalong with appropriate standards. Chapters in this sectioninelude automotive, commercial aircraft, military aircraft

and equipment, pipeline, highways, tunnels and bridges,marine piers and docks, electric power, nuelear power, steamgeneration, fIue gas desulfurization, electronics, telecom-munications, metal processing, chemical processing, pulpand paper, petroleum production and refining, food andbeverage, water handling systems, medical and dental, andpharmaceutical.

Section VIII on Corrosion-Related Standards (H. Hackand R. Baboian, Section Editors) is a comprehensive listof standards developed by various organizations ineludingthe American Petroleum Institute, American WaterworksAssociation, ASME International, ASTM International,International Electrotechnical Commission, ISO, NACEInternational, SAE International, and the Steel StructuresPainting Council. The standards are listed and grouped ac-cording to subject within each organization. The accompa-nying CD ineludes many of the ASTM and NACE cOITosionstandards.

The revised Manual 20 on COITosion Tests and Standardsis certain to serve as a valuable resource for those in indus-try, government, and academia. Acknowledgment is given tothe many authors who wrote the chapters providing theimportant information in this revision. Also acknowledgedare the reviewers who work anonymously to help maintaina high level of quality throughout the book. The work of theeditors can only be completed through the dedication andcompetence of these persons.

Robert BaboianEditor

MNL20-2ND-EB/Jan. 2005

Section 1: GenerallnformationR. Baboian, Editor

Contents

Unified Numbering System for Metals and A1loysExamples of Common Names of Selected UNS AlloysStandard Terminology Relating to Corrosion and Corrosion TestingGlossary of Corrosion-Related AcronymsStandard Abbreviations and Unit SymbolsIntemational System of Units (SI)General Conversion FactorsCondensed Metric Practice Guide for CorrosionMultiplication Factors (SI Prefixes)Corrosion Rate Conversion FactorsCorrosion Rate Calculation (from Mass Loss)Corrosion Rate Conversion FactorsDensities/K Factors for AlloysOvervoltage ValuesReference Potentials and Conversion TableEquivalent Weight Values for Metals and AlloysConstants Used in Faraday's EquationPhysical Properties of Gases and LiquidsPhysical Properties of ElementsDensities of Metals and AlloysDensity of MaterialsThermal Expansion Coefficients for AlloysPhysical Properties of WaterDew Point of Moist AirChemical Cleaning Procedures for Removal of COITosion ProductsElectrolytic Cleaning Procedures for Removal of COITosion Products

3

ReferenceNACENACEASTM G 15NACEASTMASTM E 380ASTM E380ASTMASTME 380WranglnASTM G 1NACENACEVariousASTMG3ASTM G 102ASTM G 102ASTMASTMASTM G 1ASMNACEVariousNACEASTM G 1ASTM G 1

Copyright 25by ASTM International www.astm.org

MNL20-2ND-EB/Jan. 2005

Unified Numbering 5ystemtor Metals and Alloys1

UNSSERIESNonferrous Metals and Alloys

AOOOO l-A99999COOOO 1-C99999EOOOO 1-E99999LOOOO 1-L99999M00001-M99999NOOOO 1-N99999POOOO 1-P00999P01001-P01999P02001-P02999P03001-P03999P04001-P04999POSOOI-POS999P06001-P06999P07001-P07999ROlO11-R01999R0200 1-R02999R03001-R03999R04001-R04999ROS001-ROS999R06001-R06999R07001-R07999ROSOO 1-ROS999RIOOOI-R19999R20001-R29999R3 0001-R3 9999R40001-R49999RSOOO 1-RS9999R60001-R69999ZOOOO 1-Z99999

Ferrous Metals and AlloysD00001-D99999FOOOO1-F99999GOOOO 1-G99999H00001-H99999JOOOO1-J99999K00001-K99999SOOOO 1-S99999TOOOO1-T99999

Welding Filler Metals, Classifiedby Weld Deposit Composition

W00001-W09999W 10000-W19999W20000-W29999W30000-W39999W40000-W49999WSOOOO-WS9999W 60000-W 69999W70000-W79999WSOOOO-WS9999

Metal

Aluminum and aluminum alloysCopper and copper alloysRare earth and rare earth-like metals and alloysLow melting metals and alloysMiscellaneous nonferrous metals and alloysNickel and nickel alloysGoldIridiumOsmiumPalladiumPlatinumRhodiumRutheniumSilverBoronHafniumMolybdenumNiobium (Columbium)TantalumThoriumTungstenVanadiumBeryIliumChromiumCobaltRheniumTitaniumZirconiumZinc and zinc alloys

Specified mechanical properties steelsCast ironsAISI and SAE carbon and alloys steels (except tool steels)AISI H-steelsCast steels (except tool steels)Miscellaneous steels and ferrous alloysHeat- and corrosion-resistant (stainless) steelsTool steels

Carbon steel with no significant alloying elementsManganese-molybdenum low-alloy steelsNickellow-alloy steelsAustenitic stainless steelsFerritic stainless steelsChromium low-alloy steelsCopper-base alloysSurfacing alloysNickel-base alloys

lSeeNACE Corrosion Engineers Reference Book, Third Edition,R. Baboian, Ed., NACE InternationaJ. 2002, p. 233.

4

MNL20-2ND-EB/Jan. 2005

Examples of Common Namesof Selected UNS Alloys1

Nonferrous

A02420 Al 242.0A05140 Al 514.0A91060 Al 1060A92024 Al 2024A95083 Al 5083A96061 Al 6061C10200 OF CopperC14200 DPA CopperC26000 Cartridge BrassC44300 Admiralty Brass, AsC46500 Naval Brass, AsC60600 Aluminum Bronze, 6 %C63000 Nickel Aluminum BronzeC68700 Aluminium Brass, AsC75200 Nickel SilverC90500 Gun Metal95800 Cast Ni-Al BronzeL50045 Common LeadMl1311 MgAZ31BM13310 Mg HK31AN02200 Nickel 200N04400 400 AlloyN05502 502 AlloyN06022 C-22 AlloyN06333 RA333 AlloyN06601 601 AlloyN06690 690 AlloyN07001 WaspaloyN07090 90 AlloyN07750 X-750 AlloyN08026 20Mo-6N08330 RA-330N08700 JS700N08810 800H AlloyN08904 904L AlloyN09925 925 AlloyN 10003 N AlloyN10685 B-2 AlloyR03600 MolybdenumR042 10 Niobium (Columbium)R30003 ElgiloyR30031 Stellite 31

A02950 Al 295.0A05200 Al 520.0A91100 Al 1100A93003 Al 3003A95086 Al 5086A96063 Al 6063C11000 ETP CopperC22000 Commercial BronzeC27000 Yellow BrassC44400 Admiralty Brass, sbC51000 Phosphor Bronze AC61300 Aluminum Bronze, 7 %C65500 High-Silicon BronzeC70600 90-10 Copper-NickelC83600 Ounee MetalC92200 M BronzeC96400 Cast 70-30 Cu-NiL51120 Chemieal LeadMl1914 Mg AZ91C

N02201 Nickel201N04405 R-405 AlloyN06002 X AlloyN06030 G-30 AlloyN06455 C-4 AlloyN06617 617 AlloyN06975 2550 AlloyN07031 31 AlloyN07716 625 PlusN08020 20Cb-3N08028 Sanicro 28N08366 AL-6XN08800 800 AlloyN08811 800HT AlloyN08925 25-6MoN 10001 B AlloyN10004 W Alloy

R03630 Molybdenum AlloyR05200 TantalumR30004 HavarR30035 MP35N

A03560 Al 356.0A24430 Al B443.0A92014 Al 2014A95052 Al 5052A95154 Al 5154A97075 Al 7075C12200 DHPCopperC23000 Red BrassC28000 Muntz MetalC44500 Admiralty Brass, PC52400 Phosphor Bronze DC61400 Aluminum Bronze DC67500 Mangenese Bronze AC71500 70-30 Copper-NickelC86500 Mangenese BronzeC95700 Cast Mn-Ni-Al Bronze

L55030 SO/50 SolderM12330 Mg EZ33A

N02230 Nickel 230N05500 K-500 AlloyN06007 G AlloyN06110 AllcorN06600 600 AlloyN06625 625 AlloyN06965 G-3 AlloyN07041 Rene 41N07718 718 AlloyN08024 20Mo-4N08320 20 ModN08367 AL-6XNN08801 801 AlloyN08825 825 AlloyN09706 706 AlloyN10002 C AlloyN10276 C-276 Alloy

R03650 Molybdenum, low CR07005 TungstenR30006 Stellite 6R30155 N-155

1See NACE Corrosion Engineers Reference Book, Third Edition,R. Baboian, Ed., NACE International, 2002, pp. 234-235.

5

6 CORROSION TESTS AND STANDARDS MANUAL

NonferrousR30188 HS-188 AlioyR30605 L-605 AlloyR50550 Ttanium, Gr 3R52400 Titanium, Gr 7R56260 Ti6Al6Mo2Sn4ZrR58640 Beta-CR60705 Zr 705Z13000 Zinc Anode Type 11

F10006 Gray Cast IronF41000Ni-Resist Type 1F43000 Ductiie Ni-Resist D2G10200 1020 Carbon SteeiJ91150 CA-15J91540 CA-6NMJ92600 CF-81292605 HCJ92710 CF-8CJ93000 CG-8MJ93370 CD-4MCuJ93503 HHJ94203 HK-30J94224 HKN08007 CN-7MK01800 A516-55K02700 A516-70K03006 A106-BK11576 HSLA SteeiK41545 5Cr-0.5MoK94610 KOVARS13800 PH 13-8 MoS17400 17-4 PHS20100 201 SSS21400 TeneionS2190021-6-9S30200 302 SSS30403 304L SSS30453 304LN SSS30815253MAS31000 310 SSS31254 254 SMOS315003RE60S31609 316H SSS31651 316N SSS31703 317L SSS31803 2205 AlioyS32304 SAF 2304S32900 329 SSS34709 347H SSS35500 AM 355S40300 403 SSS41000 410 SSS41800 Greek AscoloyS42400 F6NMS43100 431 SSS44002 440A SSS44200 442 SSS4462526-1S44635 26-4-4S4473529-4CS45500 Custom 455S50300 7Cr-0.5Mo

R30260 Duratherm 2602R50250 Titanium, Gr 1R50700 Titanium, Gr 4R53400 Titanium, Gr 12R56320 Titanium, Gr 9R60702 Zr 702

Z32120 Zinc Anode Type 1Ferrous

F20000 Malleable Cast IronF41002 Ni-Resist Type 2F43006 Ductile Ni-Resist D5G41300 4130 SteeiJ91151 CA-15MJ91803 CB-30J92602 CF-20J92615 CC-50J92800 CF-3MJ93001 CG-12J93402 CH-20J94003 HIJ94204 HK-40N08604 HLN08004 HUK02100 A516-60K02801 A285-CK11510 0.2Cu SteelKl1597 1.25Cr-0.5MoK81340 9Ni Steel

S15500 15-5 PHS17600 Stainless WS20200 202 SSS21600 216 SSS24000 18-3 MnS30300 303 SSS30409 304H SSS30500 305 SSS30900 309 SSS31006 310S SSS31260 DP-3S31600 316 SSS31635 316Ti SSS31635 316LN SSS31725 317LM SSS32100 321 SSS32404 Uranus 50S32950 7-Mo PlusS34800 348 SSS36200 Almar 362S40500 405 SSS41400 414 SSS42000 420 SSS42900 429 SSS43400 434 SSS44003 440B SSS4440018-2S44626 26-1 TiS44660 SC-1S44800 29-4-2S50100 5Cr-0.5MoS50400 9Cr-1Mo

R30556 HS-556R50400 Titanium, Gr 2R52250 Ttanium, Gr 11R54520 Ttanium, Gr 6R56400 Ttanium, Gr 5R60704 Zr 704

Z32121 Zinc Anode Type III

F32800 Ductile Iron 60-40-18F41006 Ni-Resist Type 5F47003 DunronG43400 4340 SteeiJ91153 CA-40J92500 CF-3J92603 HFJ92701 CF-16FJ92900 CF-8MJ93005 HDJ93423 CE-30J94202 CK-20J94213 HNN08002 HTN08705 HPK02403 A516-65K03005 A53-BKl1522 C-0.5MoK215902.25Cr-1MoK909419Cr-1Mo

S15700 PH 15-7 MoSl7700 17-7 PHS20910 22-13-5S21800 Ntronic 60S28200 18-18 PlusS30400 304 SSS30451 304N SSS30800 308 SSS30906 309S SSS3120044LNS31400 314 SSS31603 316L SSS31640 316Cb SSS31700 317 SSS31726 317L4 SSS32109 321H SSS32550 Ferralium 255S34700 347 SSS35000 AM 350S3810018-18-2S40900 409 SSS41600 416 SSS42200 422 SSS43000 430 SSS43500 436 SSS44004 440C SSS44600 446 SSS44627 26-1 CbS4470029-4S45000 Custom 450S50200 5Cr-0.5MoS66286 A286

MNL20-2ND-EB/Jan. 2005Designation: G 15-04

Standard Terminology Relating toCorrosion and Corrosion Testing 1

This standard is issued under the fixed designation G 15; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indieates the year of last reapproval.A superseript epsilon (E) indieates an editorial ehange sinee the last revision or reapproval.

This standard has been approved for use by agencies of the Department ofDefense.

anodic protection-a technique to reduce the corrosionrate of a metal by polarizing it into its passive regionwhere dissolution rates are low.

anolyte-the electrolyte adjacent to the anode of an electro-lytic ceH.

auxiliary electrode-See counter electrode.breakdown potential-the least noble potential where pitting

or crevice corrosion, or both, wiH initiate and propagate.cathode-the electrode of an electrolytic ceH at which re-

duction is the principal reaction. (Electrons flow towardthe cathode in the external circuit.)

cathodic corrosion--corrosion of a metal when it is acathode. (It usuaHy happens to metals because of a risein pH at the cathode or as a result of the formation ofhydrides.)

cathodic inhibitor-a corrosion inhibitor whose primaryaction is to slow the kinetics of the cathodic reaction,producing a negative shift in corrosion potential.

cathodic polarization-the change of the electrode poten-tial in the active (negative) direction due to current flow.(See polarization.)

cathodic protection-a technique to reduce the corrosionrate of a metal surface by making it the cathode of anelectrochemical ceH.

catholyte-the electrolyte adjacent to the cathode of anelectrolytic ceH.

cation-a positively charged ion.caustic cracking-stress corrosion cracking of metals in

caustic solutions. (See also stress-corrosion cracking.)caustic embrittlement-See caustic cracking.cavitation-the formation and rapid coHapse within a liquid

of cavities or bubbles that contain vapor or gas or both.cavitation cOITosion-the conjoint action of cavitation-

erosion and corrosion.cavitation damage-the degradation of a solid body result-

ing from its exposure to cavitation. (This may includeloss of material, surface deformation, or changes inproperties or appearance.)

cavitation-erosion-loss of material from a solid surface dueto mechanical action of continuing exposure to cavitation.

chemical conversion coating-a protective or decorativenonmetallic coating produced in situ by chemical reactionof a metal with a chosen environment. (It is often used toprepare the surface prior to the application of an organiccoating.)

1. Scope1.1 This terminology covers commonly used terms in the

field of corrosion. Related terms may be found in Terminol-ogies D 16, D 4538, G 40, or other ASTM terminology stan-dards. All terms defined by ASTM committees may be foundin the ASTM Dictionary ofEngineering & Technology.2. Referenced Documents

2.1 ASTM Standards:2D 16 Terminology for Paint, Related Coatings, Materials,and ApplicationsD 4538 Terminology Relating to Protective Coating andLining Work for PowerG 40 Terminology Relating to Wear and Erosion

3. TerminologyAC impedance-See electrochemical impedance.active-the negative direction of electrode potential. (Also

used to describe corrosion and its associated potentialrange when an electrode potential is more negative thanan adjacent depressed corrosion rate [passive] range.)

anon-a negatively charged ion.anode-the electrode of an electrolytic ceH at which oxida-

tion is the principal reaction. (Electrons flow away fromthe anode in the external circuito It is usuaHy the electrodewhere corrosion occurs and metal ions enter solution.)

anode corrosion efficiency-the ratio of the actual corro-sion (weight loss) of an anode to the theoretical corro-sion (weight loss) calculated by Faraday's law from thequantity of electricity that has passed.

anodic inhibitor-a corrosion inhibitor whose primaryaction is to slow the kinetics of the anodic reaction, pro-ducing a positive shift in corrosion potential.

anodic polarization-the change of the electrode potentialin the noble (positive) direction due to current flow. (Seepolarization.)

1 This terminology is under the jurisdiction of ASTM CornrnitteeGOl on Corrosion of Metals and are the direct responsibility ofSubcornmittee G01.02 on Terminology.

Current edition approved Jan. 1, 2004. Published January 2004.Originally approved in 1971. Last previous edition approved in2003 as G lS-03a.1 For referencedASTM standards, visit the ASTM website, www.astrn.org,or contact ASTM Custorner Service at service@astrn.org. For AnnualBook ofASTM Standards volurne information, refer to the standard'sDocurnent Surnrnary page on the ASTM website.

Copyrigh@ASTM International, 100 BaIT Harbor Drive, PO Box C700, West Conshohoeken, PA 19428 2959, United States.

7

8 CORROS/ON TESTS AND STANDARDS MANUAL

concentration cell-an electrolytic cell, the emf of which iscaused by a difference in concentration of sorne componentin the electrolyte. (This difference leads to the formationof discrete cathode and anode regions.)

corrosion-the chemical or electrochemical reaction be-tween a material, usually a metal, and its environment thatproduces a deterioration of the material and its properties.

corrosion fatigue-the process in which a metal fracturesprematurely under conditions of simultaneous corrosionand repeated cyelic loading at lower stress levels or fewercyeles than would be required in the absence of the cor-rosive environment.

corrosion fatigue strength-the maximum repeated stressthat can be endured by a metal without failure under defi-nite conditions of corrosion and fatigue and for a specificnumber of stress cyeles and a specified period of time.

corrosion inhibitor-a chemical substance or combinationof substances that, when present in the proper concen-tration and forros in the environment, prevents or re-duces corrosion.

corrosion potential-the potential of a corroding surfacein an electrolyte relative to a reference electrode meas-ured under open-circuit conditions.

corrosion rate-the amount of corrosion occurring in unittime. (For example, mass change per unit area per unittime; penetration per unit time.)

counter electrode-the electrode in an electrochemical cellthat is used to transfer current to or from a test electrode.

crevice corrosion-localized corrosion of a metal surfaceat, or immediately adjacent to, an area that is shieldedfrom full exposure to the environment because of eloseproximity between the metal and the surface of anothermaterial.

critical anodic current density-the maximum anodiccurrent density observed in the active region for a metalor alloy electrode that exhibits active-passive behavior inan environment.

critical humidity-the relative humidity above which the at-mospheric corrosion rate of sorne metals increases sharply.

critica1 pitting potential-the least noble potential wherepitting corrosion will initiate and propagate. (See break-down potential.)

current density-the electric current to or from a unit areaof an electrode surface.

current efficiency-the ratio of the electrochemical equiva-lent current density for a specific reaction to the totalapplied current density.

deactivation-the process of prior removal of the active cor-rosive constituents, usually oxygen, from a corrosive liquidby controlled corrosion of expendable metal or by otherchemical means, thereby making the liquid less corrosive.

dealloying-See parting.depolarization-not a preferred termo (See polarization.)deposit corrosion-localized corrosion under or around a

deposit or collection of material on a metal surface. (Seealso crevice corrosion.)

dezincification-See parting; specific to copper-zinc alloys.differential aeration cell (oxygen concentration cell)-a

concentration cell caused by differences in oxygen con-centration along the surface of a metal in an electrolyte.(See concentration cell.)

diffusion limited current density-the current density,often referred to as limiting current density, that corre-sponds to the maximum transfer rate that a particularspecies can sustain due to the limitation of diffusion.

electrochemical admittance-the reciprocal of the elec-trochemical impedance, MIM..

electrochemical cell-an electrochemical system consisting ofan anode and a cathode in metallic contact and irnmersed inan electrolyte. (The anode and cathode may be differentmetals or dissimilar areas on the same metal surface.)

electrochemical impedance-the frequency dependent,complex valued proportionality factor, bEIM, betweenthe applied potential (or current) and the response cur-rent (or potential) in an electrochemical cell. This factorbecomes the impedance when the perturbation and re-sponse are related linearly (the factor value is independ-ent of the perturbation magnitude) and the response iscaused only by the perturbation. The value may be re-lated to the corrosion rate when the measurement ismade at the corrosion potential.

electrochemical noise-fluctuations of the current, orboth, originating from uncontrolled variations in a cor-rosion process.

electrochemical potential (electrochemical tension)-the partial derivative of the total electrochemical free en-ergy of the system with respect to the number of moles ofthe constituent in a solution when all other factors areconstant. (Analogous to the chemical potential of theconstituent except that it ineludes the electrical as well asthe chemical contributions to the free energy.)

electrode potentia1-the potential of an electrode in anelectrolyte as measured against a reference electrode.(The electrode potential does not inelude any resistancelosses in potential in either the solution or external cir-cuit. It represents the reversible work to move a unitcharge from the electrode surface through the solution tothe reference electrode.)

electrolysis--production of chemical changes of the electrolyteby the passage of current through an electrochemical cell.

electrolytic cleaning-a process of removing soil, scale orcorrosion products from a metal surface by subjecting itas an electrode to an electric current in an electrolyticbath.

Electromotive Force Series (EMF Series)-a list of ele-ments arranged according to their standard electrode po-tentials, with "noble" metals such as gold being positiveand "active" metals such as zinc being negative.

embrittlement-the severe loss of ductility or toughness orboth, of a material, usually a metal or alloy.

environmentally-assisted cracking-the initiation or accele-ration of a cracking process due to the conjoint action ofa chemical environment and tensile stress.

equilibrium (reversible) potentia1-the potential of anelectrode in an electrolytic solution when the forwardrate of a given reaction is exactly equal to the reverserateo (The equilibrium potential can only be defined withrespect to a specific electrochemical reaction.)

erosion-the progressive loss of material from a solid sur-face due to mechanical interaction between that surfaceand a fluid, a multi-component fluid, or solid particlescarried with the fluid.

erosion-corrosion-a conJomt action involving corrosionand erosion in the presence of a moving corrosive fluid,leading to the accelerated loss of material.

exchange current density-the rate of charge transfer perunit area when an electrode reaches dynamic equilibrium(at its reversible potential) in a solution; that is, the rateof anodic charge transfer (oxidation) balances the rate ofcathodic charge transfer (reduction).

exfoliation--correction that proceeds laterally from thesites of initiation along planes parallel to the surface,generally at grain boundaries, forming corrosion prod-ucts that force metal away from the body of the material,giving rise to a layered appearance.

external circuit-the wires, connectors, measuring devices,current sources, and so forth, that are used to bringabout or measure the desired electrical conditions withinthe test cell.

filifonn corrosion--corrosion that occurs under sorne coatingsin the form of randomly distributed threadlike filaments.

fretting corrosion-the deterioration at the interface be-tween contacting surface as the result of corrosion andslight oscillatory slip between the two surfaces.

galvanic corrosion-accelerated corrosion of a metal be-cause of on electrical contact with a more noble metal ornonmetallic contactor in a corrosive electrolyte.

galvanic couple-a pair of dissimilar conductors, commonlymetals, in electrical contact (See galvanic corrosion.)

galvanic current-the electric current between metals orconductive nonmetals in a galvanic couple.

galvanic series-a list of metals and alloys arranged ac-cording to their relative corrosion potentials in a givenenvironment.

galvanodynamic-refers to a technique wherein current,continuously varied at a selected rate, is applied to anelectrode in an electrolyte.

galvanostaircase-refers to a galvanostep technique forpolarizing an electrode in a series of constant currentsteps wherein the time duration and current incrementsor decrements are equal for each step.

galvanostatic-an experimental technique whereby an elec-trode is maintained at a constant current in an electrolyte.

galvanostep-refers to a technique in which an electrode ispolarized in a series of current increments or decrements.

grain dropping-the dislodgement and loss of a grain orgrains (crystals) from a metal surface as a result of inter-granular corrosion.

graphitic corrosion-the deterioration of metallic con-stituents in gray cast iron, which leaves the graphic par-tides intacto (The term "graphitization" is commonlyused to identify this form of corrosion but is not recom-mended because of its use in metallurgy for the decom-position of carbide to graphite.)

hot corrosion-an accelerated corrosion of metal surfacesthat results from the combined effect of oxidation and reac-tions with sulfur compounds and other contaminants, suchas chlorides, to form a molten salt on a metal surface whichfluxes, destroys, or disrupts the normal protective oxide.

hydrogen blistering-the formation of blisters on or belowa metal surface from excessive internal hydrogen pres-sure. (Hydrogen may be formed during deaning, plating,corrosion, and so forth.)

STANDARD TERMINOLOGY 9

hydrogen embrittlement-hydrogen-induced cracking orsevere loss of ductility caused by the presence of hydro-gen in the metal.

immunity-a state of resistance to corrosion or anodic dis-solution of a metal caused by thermodynamic stability ofthe metal.

impingement corrosion-a form of erosion-corrosion gen-erally associated with the local impingement of a high-velocity, flowing fluid against a solid surface.

impressed current-an electric current supplied by a deviceemploying a power source that is external to the electrodesystem. (An example is dc current for cathodic protection.)

intensiostatic-See galvanostatic.intercrystalline corrosion-See intergranular corrosion.intergranular corrosion-preferential corrosion at or ad-

jacent to the grain boundaries of a metal or alloy.intemal oxidation-the formation of isolated particles of corro-

sion products beneath the metal surface. (This oceurs as theresult of preferential oxidation of certain alloy constituents byinward diffusion of oxygen, nitrogen, sulfur, and so forth.)

knife-Iine attack-intergranular corrosion of an alloy, usu-ally stabilized stainless steel, along a line adjoining or incontact with a weld after heating into the sensitizationtemperature range.

local action corrosion-corrosion caused by local corro-sion cells on a metal surface.

local corrosion cell-an electrochemical cell created on ametal surface because of a difference in potential be-tween adjacent areas on that surface.

localized corrosion--corrosion at discrete sites, for example,pitting, crevice corrosion, and stress corrosion cracking.

long-Une current-electric current through the earth froman anodic to a cathodic area of a continuous metallicstructure. (Usually used only where the areas are sepa-rated by considerable distance and where the current re-sult from concentration-cell action.)

Luggin probe or Luggin-Haber capillary-a device usedin measuring the potential of an electrode with a signifi-cant current density imposed on its surface. (The probeminimizes the IR drop that would otherwise be indudedin the measurement and without significandy disturbingthe current distribution on the specimen.)

macrocell corrosion--corrosion of a metal embedded in po-rous media (for example, concrete or soil) caused by con-centration or galvanic cells which exist on a scale at least aslarge as the smallest major dimension of the corroding item(for example, the diameter of a bar pipe).

metal dusting-accelerated deterioration of metals in car-bonaceous gases at elevated temperature to form a dust-like corrosion producto

metallizing-See thermal spraying.microbial corrosion-corrosion that is affected by the

action of microorganisms in the environment.microbiologicalIy influenced corrosion (MIC)--corrosion

inhibited or accelerated by the presence or activity, orboth, of microorganisms.

mixed potential-the potential of a specimen (or speci-mens in a galvanic couple) when two or more electro-chemical reactions are occurring simultaneously.

noble-the positive (increasingly oxidizing) direction ofelectrode potential.

10 CORROSION TESTS AND STANDARDS MANUAL

noble metal-a metal with a standard electrode potentialthat is more noble (positive) than that of hydrogen.

occ1uded cell-an electrochemical cell created at a local-ized site on a metal surface which has been partially ob-structed from the bulk environment.

open-circuit potential-the potential of an electrodemeasured with respect to a reference electrode or an-other electrode when no current flows to or from it.

overvoltage-the change in potential of an electrode from itsequilibrium or steady state value when current is applied.

oxidation-loss of electrons by a constituent of a chemicalreaction. (Also refers to the corrosion of a metal that isexposed to an oxidizing gas at elevated temperatures.)

parting-the selective corrosion of one or more compo-nents of a solid solution alloy.

parting limit-the minimum concentration of a more noblecomponent in an alloy, above which parting does not oc-cur in a specific environment.

passivation-the process in metal corrosion by which met-als become passive. (See passive.)

passivator-a type of inhibitor which appreciably changesthe potential of a metal to a more noble (positive) value.

passive-the state of the metal surface characterized by lowcorrosion rates in a potential region that is strongly oxi-dizing for the metal.

passive-active cell-a corrosion cell in which the anode isa metal in the active state and the cathode is the samemetal in the passive state.

pitting--corrosion of a metal surface, confined to a point orsmall area, that takes the form of cavities.

pitting factor-ratio of the depth of the deepest pit result-ing from corrosion divided by the average penetration ascalculated from weight loss.

polarization-the change from the open-circuit electrodepotential as the result of the passage of current.

polarization admittance-the reciprocal of polarizationresistance (dUdE).

polarization resistance-the slope (dE/di)at the corrosionpotential of potential (E)-current density (i) curve. (11 isinversely proportional to the corrosion current densitywhen the polarization resistance technique is applicable.)

potentiodynamic-refers to a technique wherein the poten-tial of an electrode with respect to a reference electrodeis varied at a selected rate by application of a currentthrough the electrolyte.

potentiostaircase-refers to a potentiostep technique forpolarizing an electrode in a series of constant potentialsteps wherein the time duration and potential incre-ments or decrements are equal for each step.

potentiostat-an instrument for automatically maintainingan electrode in an electrolyte at a constant potential or con-trolled potentials with respect to a suitable reference eleetrode.

potentiostatic-the technique for maintaining a constantelectrode.

potentiostep--refers to a technique in which an electrode ispolarized in a series of potential increments or decrements.

poultice corrosion-See deposit cOITosion.Pourbaix diagram (electrode potential-pH diagram)-a

graphic representation showing regions of thermodynamicstability of species in metal-water electrolyte systems.

primary passive potential (passivation potential)-thepotential corresponding to the maximum active current

density (critical anodic current density) of an electrodethat exhibits active-passive corrosion behavior.

protection potential-the most noble potential where pit-ting and crevice corrosion will not propagate.

redox potential-the potential of a reversible oxidation-reduction electrode measured with respect to a referenceelectrode, corrected to the hydrogen electrode, in a givenelectrolyte.

reduction-the gain of electrons by a constituent of achemical reaction.

reference electrode--electrode having a stable and repro-ducible potential, which is used in the measurement ofother electrode potentials.

rest potential-See open-circuit potential.rust-a corrosion product consisting primarily of hydrated

iron oxide. (A term properly applied onIy to ferrous aHoys.)sample-a portion of material taken from a larger quantity

and representative of the whole, to be used for test pur-poses.

season cracking-See stress-coITosion cracking.sensitization-a process resulting in a metallurgical condi-

tion which causes susceptibility of an alloy to intergranu-lar corrosion or intergranular environmentally assistedcracking in a specific environment.

specimen-a prepared portion of a sample upon which atest is intended to be performed.

stray current corrosion-the corrosion caused by electriccurrent from a source external to the intended electricalcircuit, for example, extraneous current in the earth.

stress-corrosion cracking-a cracking process that requiresthe simultaneous action of a corrodent and sustainedtensile stress. (This excludes corrosion-reduced sectionswhich fail by fast fracture. It also excludes intercrystal-line or transcrystalline corrosion which can disintegratean alloy without either applied or residual stress.)

subsurface corrosion-See internal oxidation.sulfidation-the reaction of a metal or alloy with a sulfur-

containing species to produce a sulfur compound thatforms on or beneath the surface of the metal or aHoyo

Tafel slope-the slope of the straight line portion of apolarization curve, usually occurring at more than 50 mVfrom the open-circuit potential, when presented in asemi-logarithmic plot in terms of volts per logarithmiccycle of current density (commonIy referred to as voltsper decade).

thermal spraying-a group of processes wherein finelydivided metallic or nonmetallic materials are depositedin a molten or semimolten condition to form a coating.(The coating material may be in the form of powder, ce-ramic rod, wire,or molten materials.)

thermogalvanic corrosion-the corrosive effect resultingfrom the galvanic cell caused by a thermal gradientacross the metal surface.

transpassive region-the region of an anodic polarizationcurve, noble to and above the passive potential range, inwhich there is a significant increase in current density(increased metal dissolution) as the potential becomesmore positive (noble).

tuberculation-the formation of localized corrosion prod-ucts that appear on a surface as knoblike prominences(tubercules).

uniform corrosion--corrosion that proceeds at about thesame rate over a metal surface.

weld decay-not a preferred termo Integranular corrosion,usually of stainless steels or certain nickel-base alloys,

STANDARD TERMINOLOGY 11

that occurs as the result of sensitization in the heat-affected zone during the welding operation.

working electrode-the test or specimen electrode in anelectrochemical cell.

Thls standard is subjecl lo revision a/ any time by Ihe responsible lechnical commiHee andmusl be reviewed everylive years and il nol revisec!, eifher reapproved or wifhdrawn. Your commenls are inviled ei/her lor revision ol/hisslandard or lor addilional slandards and should be addressed lo ASTM Inlemalional Headquarfers. Your commenls willrecelve carelul considerafion a/ a meeting ol/he responslble lechnical commiHee, which you may aHend 11 you leelIha/ your commenls have nol received a lair hearing you should make your views known lo /he ASTM CommiHee onStandards, a/ /he address shown be/ow.

This slandard is copyrlghled by ASTM inlemallona!.100Sa.. HarborDrive.POSoxC700.WestConshohocken.PA19428-2959, Unifed Sta/es. IndMdual reprlnls (single or mulfiple copies) 01 /his slandard may be oblained by conlaclingASTM al /he above address or a/ 610-832-9585 (phone), 610-832-9555 (Iax), or service@aslm.org (e-mai!); or Ihrough /heASTM websife (www.asfm.org).

MNL20-2ND-EB/Jan. 2005

Glossary of Corrosion-RelafedAcronyms1

1 See NACE Corrosion Engineers Reference Book, Third Edition,R. Baboian, Ed., NACE International, 2002, p. 33.

ABSACAEAESANNAUSSAVTBFWBWRCABCCICCTCDCDACFCHCHACNCPCPPCPTCPVCCRCRACSCSECWDCBDIMADSSDTADWECEDXAEISELNEPMAEPDMEPR

ERESCAEW

Acrylonitrile-butadiene-styrene plasticsAir-cooledAcoustic emissionAuger electron spectroscopyAnnealedAustenitic stainless steelAll volatile treatment for BFWBoiler feedwaterBoiling water reactorCellulose acetate-butyrateCrevice corrosion indexCritical crevice corrosion temperatureCurrent densityCorrosion data acquisitionCorrosion fatigueCold work hardenedCold work hardened, agedConcentric neutralCathodic protectionCritical pitting potentialCritical pitting temperatureChlorinated poly(vinyl chloride)Cold-rolledCorrosion-resistant alloyCarbon steelCopper/copper sulfate electrodeCooling waterDouble cantilever beam testDirect imaging mass analyzerDuplex stainless steelDifferential thermal analysisDistilled waterEnvironmental crackingEnergy dispersive X-ray analysisElectrochemical impedance spectroscopyElectrochemical noise techniqueElectron beam microprobe analysisEthylene propylene elastomerElectrochemical potentiokinetic

reactivationElectrical resistanceElectron spectroscopy for chemical analysisElectric welded

FBCFBEFCFCGRFEPFGDFPMFRPFSSGMAWGTAWHAZHBHEHICHKHLLWHPWHRHRAHRBHRCHSCHSLAHTRHVNIGCIGSCCIMMAIOZISSISWSKICLASLMCLSIMASMCAMICMSSMTNGNHENMRNPSNT

Fluidized bed combustionFusion-bonded epoxy coatingFumace cooledFatigue crack growth rateFluorinated ethylene propylene polymerFlue gas desulfurizationFluorocarbon elastomersFiber-reinforced plasticFerritic stainless steelGas metal arc weldingGas tungsten arc weldingHeat-affected zoneBrinell hardness numberHydrogen embrittlementHydrogen induced crackingKnoop hardness numberHigh levelliquid waste (nuclear)High-purity waterHot-rolledHot-rolled, agedRockwell B hardness numberRockwell C hardness numberHydrogen stress crackingHigh-strength low-alloy steelHeat treatmentVickers hardness numberIntergranular corrosionIntergranular stress corrosion crackingIon microprobe mass analyzerInorganic zinc coatingIon scattering spectroscopyIllinois State Water Survey testerCritical stress intensityLow-alloy steelLiquid metal crackingLangelier saturation indexMaraging steelsMultiple crevice assemblyMicrobial induced corrosionMartensitic stainless steelMagnetic particle inspectionNuclear gradeNormal hydrogen electrodeNuclear magnetic resonanceNominal pipe sizeNormalized and tempered

12

GLOSSARY OF CORROSION-RELATED ACRONYMS 13

OCTG00OTECOZPCPDPEPFAPHSSPPCPPPRPTPTAPTFEPUPVCPVDCPVDFPWHTPWROTRHRSIRTRTPRXSAMSAWSBRSCCSCESEM

Oil country tubular goodsOil-quenchedOcean thennal energy conversinOrganic zinc coatingPolycarbonatePit depthPolyethylenePerfluoro(alkoxy-alkane) copolymerPrecipitaion hardenable stainless steelPolymer modified portland cementPolypropylenePolarization resistanceDye penetrant surveyPolythionic acidsPolytetrafluoromethylenePolyurethanePoly(vinyl choloride)Poly(vinylidene chloride)Poly(vinylidene fluoride)Post-weld heat treatmentPressurized water reactorOuenched and temperedRelative humidityRyzner saturation indexX-ray or gamma ray surveyReinforced thennoset plasticsRecrystallizedScanning Augar microscopySubmerged arc weldingStyrene-butadiene rubberStress-corrosion crackingSaturated calomel electrodeScanning electron microscopy

SIMSSMAWSMLSSMYSSRASRBSRCS/NSRESSSSCSSMSSSRSSWSTASTEMSTOSWTEMTFETSTTSURDUTUVVCIWFMTWOWOLXPSXRDYSZRP

Secondary ion mass spectroscopyShielded metal arc weldingSearnless pipe or tubingSpecified minimum yield strengthStress relief annealSulfate-reducing bacteriaSolvent-refined coalFatigue testScanning reference electrodeStainless steelSulfide stress crackingSpark sources mass spectroscopyslow strain rate testSubstitute seawaterSolution treated and agedScanning transmission electron microscopySolution treated and quenchedSeawaterTransmission electron microscopyTetrafluoroethyleneTensile strengthTemperature, time, sensitization diagramUnderground residential distribution systemsUltrasonic surveyUltraviolet spectroscopyVolatile corrosion inhibitorWet fluorescent magnetic particle inspectionWater-quenchedWedge-opening load testX-ray photoelectron spectroscopyX-ray diffractionYield strengthZinc-rich paint

ASTM Standard Abbreviationsand Unit Symbols

MNL20-2ND-EB/Jan. 2005

absoluteacademic degrees

altemating current, n.altemating current, adj.AmericanAmerican wire gageampereampere hourangstromante meridiemAssociationatmosphereaveragebarrelbecquerelbillion electronvoltsBirmingham wire gagebrave horsepowerbrake-horsepower hourBrinell hardness numberBritish thermal unitBrown and Sharpe (gage)bushelcaloriecandelacentimetrecentipoisecentistokescircular milcoefficientCompanyCorporationcoulombcubiccubic centimetrecubic decimetrecuriecycles per minutecycles per seconddaydecibeldegree (angle)degree Celsiusdegree Fahrenheitdegree Rankinedegrees of freedom

absuse periods and ron together

(M.S., Ph.D., etc.)ACA-CAm.aAWGAAhAa.m.

Assn.batmavgbblBq(use GeV, gigaelectronvolts)BWGbhpbhp. hHB (see ASTM E 10)BtuB&SbucalcdcmcPcStcmilspell outCo.bCorp.bCuse exponential formecm3

dm3Cicpm(use Hz. hertz)spell outdB

Departmentdiameterdifferentialdirect current, n.direct current, adj.Divisiondollareffective horsepowerelectromotive forceelectronvoltEngineersequation(s)faradfigure(s)footfootcandlefoot pound-force

gallongaussgilbertgraingramgravity (acceleration)grayhalfhardhenryhertzhorsepowerhorsepower hourhourHurter and Driffield scale

(film density)hydrogen ion concentration,

negative logarithm ofinchinch of mercuryinch of waterinch pound-force

inclusiveIncorporatedindicated horsepowerinside diameterInstituteintegrated neutron fluxiron pipe size

14

Dept.bdia (in figures and tables only)dDCD-CDiv.b$ehpemfeVEngrs.a

Eq(s)FFig(s).dftfcft lbf (use for work, energy)

(see lbf . ft)galGGbspell outggGyVzHHHzhphp.hhH&D

pH

in.in. Hgin. HzOin lbf (use for work, energy)

(see lbf . in.)incl (in figures and tables only)Inc.bihpID (in figures and tables only)Inst.bnvt.n/cmzIPS

ASTM STANDARD ABBREVIATIONS AND UNIT SYMBOLS 15

joule J millimetre mmK alpha radiation Ka millimetre of mercury mmHgkelvin K million electronvolts MeVkilocalorie kcal milliroentgen mRkilocycle per second (see note on cycles per second) millisecond mskilogram kg millivolt mVkilogram-calorie kg cal milliwatt mWkilogram-force kgf minimum min (in figures and tables only)kilogram metre kgm minute min (spell out when used withkilometre km minimum)kilovolt kV molal spell outkilovolt ampere kVA molar Mkiloelectronvolt keV mole molkilovolt peak kVp month (When followed by a spell outkilowatt kW date use Jan., Feb., March,kilowatt hour kWh April, May, June, July, Aug.,kip (l000 lbf) spell out Sept., Oct., Nov., Dec. Whenkip (l000 lbf) per square inch ksi there is no date, spell out.Knoop hardness number HK (see ASTM E 384) Examples: Jan. 15, 1983;lambert L January 1983)linear spell out nanometre (formerIy nmlitre L millimicron)logarithm (common) log National Nat.alogorithm (natural) In newton Nlumen 1m normal Nlux Ix number(s) (This abbreviation No(s).dmagnetomotive force mmf can often be omittedmass-to-charge ratio m/e entirely. It is usuallymaximum max (in figures and tables only) understood (as in STP 325,maxwell Mx Specimen 8, Test 14, etc).)median effective concentration ECso oersted Oemedian effective dose EDso ohm nmedian lethal concentration LCso ortho omedian lethal dose LDso ounce ozmegacycles per second (see note on cycles per second) outside diameter OD (in figures and tables only)megawatt MW page p.meta m pages pp.metre m para pmicroampere 1lA parts per billion ppbmicrocurie lICi parts per million ppmmicrofarad lIF pascal Pamicrogram lIg per use the diagonalline in express-microhenry lIH ions with unit symbolsemicroinch lIin. percent %microlitre lIL pico (prefix) pmicro-micro (prefix. use pico) p picofarad pFmicrometre (formerIy micron) lIm pint ptmicroroentgen lIR poise Pmicrosecond lIS Poisson's ratio 1I (v is preferred in appliedmicrovolt lIV mechanics)microwatt lIW post meridiem p.m.mil spell out pound lbmile spell out pound-force lbfmiles per hour mph pound-force foot lbf ft (use for torque)milliampere mA (see ft . lbf)milli-angstrom mA pound-force inch lbf in. (use for torque)millicurie mCi (see in . lbf)milliequivalent meq pound-force per square foot Ibf!ft2milligram mg pound-force per square inch psi or Ibflin.2millihenry mH pound-force per square inch psiamillilitre mL absolute

16 CORROSION TESTS AND STANDARDS MANUAL

psig

spgruse exponential form(exception: psi, ksi)C

pound-force per square inchgage quart

quartrad (dose unit)radianradio frequency, n.radio frequency, adj.radiusRailwayRailroadreference(s)relative humidity

revolution per minuterevolution per secondRockwell hardness, C scaleroentgenroot mean squareSaybolt Furol secondsSaybolt Universal secondssecondsecondarysiemensSocietysocket joint (tables and

drawings only)specific gravitysquare

standard taper (tables anddrawings only)

qt steradianrd stokesrad tensile strengthrf tertiaryr-f teslaR (in figures and tables only) thousand electronvoltsRy.b thousand poundsR.R.b thousand pounds-force perRef(s) square inchRH (in figures and tables ton

only) torrr/min United States, n.r/s United States, adj.HRC (see ASTM E 18) United Status PharmacopeiaR versusrms Vickers hardness numberSFS voltSUS volume (of a publication)s wattsec watt hourS weberSoc.b week

~ yardyearYoung's modulus

sr

Stspell outtertTkeVkipksi

spell outspell outspell out

.U.S.USPspell outHV (see ASTM E 92)VVoldWWhWbspell outydspell outE

aln footnotes and references only.bAt end of name only.CWith unit symbols only.dOnly when followed by a number.eExceptions: cpm, mph, psi.

International System of Units (51)1

MNL20-2ND-EB/Jan.2005

Quantity

lengthmass

timeelectric currentthermodynamictemperatureamount of substanceluminous intensity

plane anglesolid angle

accelerationactivity (of a radioactive source)angular accelerationangular velocityarea

densityelectric capacitanceelectric conductanceelectric field strengthelectric inductanceelectric potential differenceelectric resistanceelectromotive forceenergyentropyforcefrequencyilluminanceluminanceluminous fluxmagnetic field strengthmagnetic fluxmagnetic flux densitymagnetomotive forcepowerpressurequantity of electricityquatity of heatradiant intensityspecific heatstressthermal conductivityvelocityviscosity, dynamicviscosity, kinematicvoltagevolumewavenumberwork

UnitBase Units

metre (m)kilogram (kg)second (s)ampere (A)Kelvin (K)mole (mol)candela (cd)

Supplementary Unitsradian (rad)steradian (sr)

Derived Unitsmetre per second squareddisintegration per secondradian per second squaredradian per secondsquare metrekilogram per cubic metrefarad (F)siemens (S)volt per metrehenry (H)volt (V)ohm (n)volt (V)joule (J)joule per kelvinnewton (N)hertz (Hz)lux (Ix)candela per square metrelumen (1m)ampere per metreweber(Wb)tesla (T)ampere (A)watt (W)pascal (Pa)coulomb (e)joule (J)watt per steradianjoule per kilogram-kelvinpascal (Pa)watt per metre-kelvinmetre per secondpascal-secondsquare metre per secondvolt (V)cubic metrereciprocal metrejoule (J)

Formula

mJs2(disintegration)/srad!s2rad!sm2

kg/m3AsNANVlmV s/AW/AVlAW/ANmjlKkg. mJs2(cycle)/slmJm2cd!m2cd srAlmV sWb/m2

J/sN/m2A sNmW/srJlkg KN/m2W/mKmJsPasm

2/sW/Am3

(wave) mNm

1 See ASTM E 380, Practice for Use of the International System ofUnits (SI) (The Modernized Metric System).

17

General Conversion Factors1

MNL20-2ND-EB/Jan. 2005

Unit Conversion to Multiply by Reciproca!Linear Measure

mil (0.001 inch) micrometre 25.4 0.03937mil (0.001 inch) millimetre 0.0254 39.37inch millimetre 25.4 0.03937foot metre 0.3048 3.281yard metre 0.9144 1.0936mile kilometre 1.6093 0.6214nautical mile kilometre 1.8532 0.5396

Square Measuresquare inch square millimetre 645.2 0.00155square inch square centimetre 6.452 0.155square foot square metre 0.0929 10.764square yard square metre 0.8361 1.196acre hectare 0.4047 2.471acre square metre 4047. 0.0002471acre square foot 43560. 0.00002296square mile acre 640. 0.001562square mile square kilometre 2.590 0.3863

Volumecubic inch cubic centimetre 16.387 0.06102cubic foot cubic metre 0.02832 35.31cubic foot gallon (U.S.) 7.48 0.1337cubic foot litre 28.32 0.03531cubic yard cubic metre 0.7646 1.3079ounce (U.S., liq.) cubic centimetre 29.57 0.03382quart (U.S., liq.) litre 0.9464 1.0566ganon (U.S) ganon (Imperial) 0.8327 1.2009ganon (U.S) litre 3.785 0.2642barre! (U.S. Pertoleum) gallon (U.S) 42. 0.028barre! (U.S. Pertoleum) litre 158.98 0.00629

Massgrain milligram 64.8 0.01543ounce (avoirdupois) gram 28.35 0.03527pound (avoirdupois) kilogram 0.4536 2.205short ton metric ton 0.9072 1.1023long ton metric ton 1.0161 0.9842

Pressure or Stressatmosphere mmHg (@Oc) 760. 0.001316atmosphere pound force per inch2 14.696 0.06805atmosphere bar 1.013 0.9872atmosphere megapascal (MPa) 0.1013 9.872torr (mm Hg) pascal 133.32 0.007501inch of water pascal 248.8 0.004019

1 See ASTM E 380. Practice for Use of the Intemational System ofUnits (SI) (The Modemized Metric System).

18

GENERAL CONVERSION FACrORS 19

Unit Conversion to Multiplyby Reciprocalfoot of water pound force per inch2 0.4335 2.307dyne per centimetre2 pascal 0.1000 10.00pound force per inch2 (psi) kilopascal (kPa) 6.895 0.1450kip per inch2 (ksi) megapascal (MPa) 6.895 0.1450pound force per inch2 bar 0.06895 14.50kilp per inch2 kilogram per millimetre2 0.7031 1.4223

Work, Heat, and EnergyBritish thermal unit (Btu) joule 1055. 0.0009479foot pound-force joule 1.356 0.7375calorie joule 4.187 0.2389Btu foot pound-force 778. 0.001285kilocalorie Btu 3.968 0.252Btu kilogram metre 107.56 0.009297Btu perhour watt 0.2929 3.414watthour joule 3600. 0.0002778horse power kilowatt 0.7457 1.341

Thermal Properties(Btu per foot2, hour, F) per inch (kilocalorie per metre2, hour, OC) 0.1240 8.064

per metre(Btu per foot2, hour, F) per inch watt per metre, K 0.144 6.944Btu per foot2, hour, F kilocalorie per metre2, hour, oC 4.882 0.2048Btu per foor, hour, F watt per metre2, K 5.674 0.1762Btu per foot2 kilocalories per metre2 2.712 0.3687Btu per foot2 joule per metre2 11360. 0.00008803Miscellaneous

pound per foot3 kilogram per metr 16.02 0.06242pound per gallon (U.s) gram per litre 119.8 0.00835grains per 100 foot3 milligram per metre3 22.88 0.0437ounces per foot3 gram per metre2 305.2 0.003277pound mole (gas) cubic foot (STP) 359. 0.00279gram mole (gas) litre (STP) 22.4 0.0446day minute 1440. 0.000694week hour 168. 0.00595year hour 8766. 0.0001141U.S. bag cement kilogram 42.63 0.02346gallon (U.S) per bag cement litre per kilogram 0.0888 11.26ksi (inch)1I2 megapascal (metre)1I2 1.0989 0.9100cubic foot of water (60F) pound of water 62.37 0.01603board foot cubic metre 0.00236 423.7milliampere per foot2 milliampere per metre2 10.76 0.0929gallons (U.S.) per minute metre3 per day 5.451 0.1835pound-force newton 4.448 0.2248

Condensed Metric PracticeGuide for Corrosion1,2

MNL20-2ND-EB/Jan. 2005

Multiply

inch2inch2foot2foot2yar:d2

dyne centimetrepound-force inchpound-force foot

mil per year (mpy)mil peryearinch per year (ipy)inch per month (ipm)milligram per decimetre2day (mdd)milligram per decimetre2 daymilligram per decimetre2 day

milliampere per millimetre2milliampere per centimetre2microampere per centimetre2milliampere per metre2microampere per millimetre2microampere per foot2ampere per inch2ampere per foot2ampere per centimetre2ampere per decimetre2

British therrnal unit (Btu) (60F)calorie (mean)foot-pound-forcekilocalorie (mean)kilowatt hour

foot3 per secondfoot3 per secondfoot3 per minutegallon (U.S. liquid) per minutegallon (U.S. liquid) per hourgallon (U.S.liquid) per day

dynekilogram-forceounce-forcepound-force

angstromangstrommicronmicronmilmil

ByArea645.2

6.4520.09290

929.00.836 1

Bending Moment (Torque)0.00000010.113 O1.356

Corrosion Rate0.02540

25.4025.40

304.80.100 O0.004 167

100.0Current Density

1000.10.00omo 000.0010001.000

10.761550.

10.7610000.

100.0Energy1055.

4.1901.356

4190.3.600

Flow, Volume Per Unit Time0.02832

2445.40.78

5.4510.090850.003785Force0.000019.8070.278 O4.448Length1 X lO-lO0.100 O0.00101.0000.02540

25.40

20

To Convert to SI Units:

millimetre2 (mm2)centimetre2 (cm2)metre2 (m21centimetre (cm2)metre2 (m2)

newton metre (Nm)newton metre (N'm)newton metre (N'm)

millimetre per year (mm/y)"micrometre per year (mm/y)millimetre per year (mm/y)millimetre per year (mm/y)gram per metre2day (g/m2 d)"gram per metre2 hour (g/m2.h)milligram per metre2 day (mg/m2.d)

ampere per metre2 (Alm2)ampere per metre2 (Alm2)ampere per metre2(Alm2)ampere per metre2(Alm2)ampere per metre2 (Alm2)milliampere per metre2(mAIm2)ampere per metre2(Alm2)ampere per metre2 (Alm2)ampere per metre2 (Alm2)ampere per metre2 (Alm2)

joule (J)joule (J)joule (J)joule (J)megajoule (MJ)

metre3 per second (m3/s)metre3 per day (m3/d)metre3 per day (m3/d)metre3 per day (m3/d)metre3 per day (m3/d)metre3 per day (m3/d)

newton (N)newton (N)newton (N)newton (N)

metre (m)nanometre (nm)millimetre (mm)micrometre l1n)millimetre (mm)micrometre l1n)

CONDENSED METRIC PRACTICE CUIDE FOR CORROSION 21

Multiplyinchinchinchfootyardmile

grainouncepoundpoundton (short, 2000 lb)

ounce-mass per foot2pound-mass per foot2pound-mass per foot2pound-mass per inch2

gram per centimetre3ounce (mass) per inch3ounce (mass) per ganon (U.S. liquid)ounce (mass) per ganon (U.S.liquid)pound (mass) per foot3pound (mass) per ganon (U.S. liquid)

Btu (thermochemical) per secondhorsepower (electric)kilocalorie (thermochemical) per second

atmosphere (normal = 760 torr)centimetre of mercury (OC)dyne per centimetre2inch of mercury (600 P)inch of water (600 P)kilogram-force per metre2kip per inch2pound-force per inch2pound-force per fooe

(pound-force per inch2) inch1l2(kip per inch2) inch1l2(pound-force per inch2) inchl /2(kip per inch2) inch1l2

degree Celsiusdegree Pahrenheit

hour (mean solar)day (mean solar)month (calendar)year (calendar)

inch per secondfoot per secondInch per minutemile per hourmile per hour

By2.540

25.4025400.

0.30480.91441.609Mass

64.8028.350.4536

453.6907.2

Mass Per Unit Area305.1

4.8824882.703.1

Mass Per Unit Volume (Density)1000.1730.

7.4897.489

16.02119.8

Power1054.746.0

4184.Pressure or Stress

101 300.1333.

0.100 O3377.

248.89.8076.8956.895

47.88Stress Intensity

0.0347534.750.0010991.099

TemperatureTK = re + 273.15

re = (TF - 32)/1.8Time

3600.86400.

2.62831.54

Ve10city (Speed)25.40

0.30480.423 31.6090.447 O

Volume

To Convert to SI Units:centimetre (cm)millimetre (mm)micrometre (lm)metre (m)metre (m)kilometre (km)

milligram (mg)gram (g)kilogram (kg)gram (g)kilogram (kg)

gram per metre2(g/m2 )kilogram per metre2(kg/m2)gram per metre2 (glm2 )kilogram per metre2(kg/m2)

kilogram per metre3 (kglm3)kilogram per metre3 (kglm3)kilogram per metre3 (kglm3)gram per litre (gIL)kilogram per metre3 (kg/m3)kilogram per metre3 (kglm3)

watt (W)watt (W)watt (W)

pascal (Pa)pascal (Pa)pascal (Pa)pascal (Pa)pascal (Pa)pascal (Pa)megapascal (MPa)kilopascal (kPa)pascal (Pa)

newton per millimetre3/2 (N/mm3/2)newton per millimetre312 (N/mm312)megapascal metre l /2 (MPa .m1l2)amegapascal metre l /2(MPa .m1l2)a

ke1vin (k)degree Ce1sius (oC)

second (s)second (s)megasecond (Ms)megasecond (Ms)

millimetre per second (mm/s)metre per second (m/s)millimetre per second (mm/s)kilometre per hour (kmIh)metre per second (m/s)

inch l 16.39fluid ounce (U.S.) 29.57pint (U.S. liquid) 473.2quart (U.S. liquid) 946.4ganon (U.S. liquid) 0.003 785gallon (U.S.liquid) 3.785IThis condensed guide is under the jurisdiction of ASTM Committee G-1 on Corrosion of Metals.2This guide is based on ASTM E 380.apreferred units.

centimetre3 (cm3)centimetre3 (cm3)centimetre3 (cm3)centimetre3 (cm3)metre3 (m3)litre (L)

Multiplication Factors1

Multiplication Factor1 000000000000000000 = 1018

1 000000000000000 = 10151 000 000 000 000 = 1012

1 000000000 = 1091 000000 = 104

1000 = 103100 = 10210= 1010.1 = 10-1

0.01 = 10-20.001 = 10-3

0.000001 = 10-60.000000001 = 10-9

0.000000000001 = 10-120.000000000000001 = 10-15

0.000000000000000001 = 10-18aTo be avoided where practica!.

Prefixexa

petateragigamegakilohectoadekaadeciacentiamillimicronano

picofemtoatto

MNL20-2ND-EB/Jan. 2005

SymbolEPTGMkhdadc

m

Jln

Pfa

Relationships among Someof the Units Commonly Usedfor Corrosion Rates2

Factor for Conversion toUnit mdd glm2/d Jlm/yr mm/yr mils/yr in./yr

Milligrams per square decimetre 1 0.1 36.5/d 0.365/d 1.144/d 0.00144/dper day (mdd)

Grams per square metre per day 10 365/d 0.365/d 14.4/d 0.0144/d(g/m2/d)

Micrometres per year (Jlm/yr) 0.0274d 0.00274d 1 0.001 0.0394 0.0000394Millimetres per year (mm/yr) 27.4d 2.74d 1000 1 39.4 0.0394Mils per year (mils/yr) 0.696d 0.0696d 25.4 0.0254 1 0.001Inches per year (in./yr) 696d 69.6d 25400 25.4 1000 1NOTE: d is metal density in grams per cubic centimetre (g/cm\

1See ASTM E 380, Practice for Use of the International System ofUnits (SI) (The Modernized Metric System).2 Wrangln, G. An Introduction to Corrosion and Protection ofMetals, Chapman and Hall, 1985, p. 233.

22

MNL20-2ND-EB/Jan. 2005

Corrosion Rafe Calculafion(from Mass Loss) 1

(KxW)Corrosion rate = ( )AxTxD

whereK =a constant (see below),T = time of exposure in hours to the nearest 0.01 h,A = area in cm2 to the nearest 0.01 cm2,W = mass 10ss in g, to nearest 1 mg (corrected for any 10ss during

c1eaning (see 9.4)), andD = density in g/cm3, (see Appendix Xl of ASTM G 1).

Many different units are used to express corrosion rates. Using theaboye units for T, A, W, and D, the corrosion rate can be calculated in avariety of units with the following appropriate value of K:

Corrosion Rate Units Desired

mils per year (mpy)inches per year (ipy)inches per month (ipm)millimetres per year (mm/y)micrometres per year (/-lm/y)picometres per second (pm/s)grams per square metre per

hour (g/m2 h)milligrams per square

decimeter per day (mdd)micrograms per square metre

per second (/-lg/m2 . s)

Constant (Fe) in CorrosionRate Equation

3.45 x 1063.45 X 1032.87 X 1028.76 X 1048.76 X 1072.78 X 1061.00 X 104 X 1)"

aDensity is not needed to calculate the COITosion rate in these uruts. The densityin the constant K cancels out the density in the corrision rate equation.

lSee ASTM G 1, Practice for Preparing, Cleaning and EvaluatingCorrosion Test Specimens.

23

MNL20-2ND-EB/Jan. 2005

Corrosion Rote Conversion FactorsMils/year (mpy) = e x weightloss xK

areaxtime

Millimetres/year (rnm/y) =0.0254 mpy

Weight C FactorsLoss Area Hour Day Week Month Year

mg cm2 437 18.2 2.59 0.598 0.0498dm2 4.37 0.182 0.0259 5.98 x 10-3 4.98 X 10-4m 2 0.0437 1.82 x 10-3 2.59 X 10-4 5.98 X 10-5 4.98 X 10--6in2 67.7 2.82 0.402 0.0927 7.72 x 10-3ft2 0.470 0.0196 2.79 x 10-3 6.44 X 10-4 5.36 X 10-5

g cm2 437 x 103 182 X 102 2590 598 49.8 K is a density factordm2 4370 182 25.9 5.98 0.498 K =1.000 for carbon steeim2 43.7 1.82 0.259 0.0598 4.98 x 10-3 K factors for other al10ysin2 677 x 102 2820 402 92.7 7.72 are given on the next pageft2 470 19.6 2.79 0.644 0.0536

lb cm2 198 x 106 825 X 104 118 X 104 271 X 103 226 X 102dm2 198 x 104 825 X 102 118 X 102 2710 226m 2 198 x 102 825 118 27.1 2.26in2 307 x 105 128 X 104 182 X 103 420 X 102 3500ft2 213 x 103 8880 1270 292 24.3

EXAMPLE: A 5.0 square inch specimen of copper has a weight 10ss of 218 mg in 40 hour coITosion test.

218mpy = 67.7 x x 0.88 = 65

5.0x40

mm/yr = 0.0254 x 65 = 1.65

ISee NACE Corrosion Engineers Reference Book, Second Edition,R. S. Treseder, R. Baboian, and C. G. Munger, Eds., NACEInternational, Houston, TX, 1991.

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MNL20-2ND-EB/Jan. 2005

Densifies of Common AlloYSl(K =ratio of carbon steel density to that of alloy)

Density DensityUNS CornrnonNarne g/crn3 K UNS CornrnonName g/crn3 K

A91100 Al 1100 2.72 2.89 N06007 GAlloy 8.34 0.94A93003 Al 3003 2.74 2.87 N06022 C-22 Alloy 8.69 0.90A95052 Al 5052 2.68 2.93 N06030 G-30 Alloy 8.22 0.96A96061 Al 6061 2.70 2.91 N06455 C-4 Alloy 8.64 0.91A97075 Al 7075 2.80 2.81 N06600 600 Alloy 8.47 0.93C11000 ETP Copper 8.94 0.88 N06601 601 Alloy 8.11 0.97C22000 Commercial Bronze 8.89 0.88 N06625 625 Alloy 8.44 0.93C23000 Red Brass 8.75 0.90 N06985 G-3 Alloy 8.30 0.95C26000 Cartridge Brass 8.53 0.92 N07001 Waspaloy 8.19 0.96cnooo Yellow Brass 8.39 0.94 N07041 Rene 41 8.25 0.95C28000 Muntz Metal 8.39 0.94 N07718 718 Alloy 8.19 0.96C44300 Admiralty brass. As 8.52 0.92 N07750 X-750Alloy 8.28 0.95C46500 Naval Brass. As 8.41 0.93 N08020 20cb-3 8.08 0.97C51000 Phosphor Bronze A 8.86 0.89 N08024 20Mo-4 8.11 0.97C52400 Phosphor Bronze D 8.78 0.90 N08026 20MO-6 8.13 0.97C61300 Aluminum Bronze 7 % 7.69 1.00 N08028 Sanicro 28 8.0 0.98C61400 Aluminum Bronze D 7.78 1.01 N08366 AL-6X 8.0 0.98C63000 Ni-Al Bronze 7.58 1.04 N08800 800 Alloy 7.94 0.99C65500 High-Silicon Bronze 8.52 0.92 N08825 825 Alloy 8.14 0.97C67500 Manganese Bronze A 8.36 0.94 N08904 904L Alloy 8.0 0.98C68700 Aluminum Brass. As 8.33 0.94 N08925 25-6Mo 8.1 0.97C70600 9-10 C