steel cor-ten · 8 9 nippon steel corporation 4 cor-ten can be applied without painting (in a bare...

www.nipponsteel.com SteelPlates

2-6-1 Marunouchi, Chiyoda-ku,Tokyo 100-8071 JapanTel: +81-3-6867-4111

COR-TENTM

A006en_01_201904p© 2019 NIPPON STEEL CORPORATION

COR-TEN™www.nipponsteel.com Steel

Plates

2-6-1 Marunouchi, Chiyoda-ku,Tokyo 100-8071 JapanTel: +81-3-6867-4111

COR-TENTM

A006en_01_201904f© 2019 NIPPON STEEL CORPORATION

COR-TEN™

Susa Bridge (Yamaguchi) Photo: 1992 (3 years after completion) is a registered trade name of United States Steel Corporation.

™ ™

Notice: While every effort has been made to ensure the accuracy of the information contained within this publication, the use of the information is at the reader’s risk and no warranty is implied or expressed by NIPPON STEEL CORPORATION with respect to the use of the information contained herein. The information in this publication is subject to change or modifica-tion without notice. Please contact the NIPPON STEEL CORPORATION office for the latest information. Please refrain from unauthorized reproduction or copying of the contents of this publication. The names of our products and services shown in this publication are trademarks or registered trademarks of NIPPON STEEL CORPORATION, affiliated companies, or third parties granting rights to NIPPON STEEL CORPORATION or affiliated companies. Other product or service names shown may be trademarks or registered trademarks of their respective owners.

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ContentsSaving Maintenance Cost

Features

Weather Resistance●Exposure Test Results●Secular Changes in Rust Appearance

Application Examples●Unpainted use (Bare)●Unpainted use (Complementary Rust Stabilization Treatment)●Painted use●CORQ™ (Cast Metal)●VINCOR●Various Application Examples

Specification●Steel Grades and Features●Chemical Composition●Mechanical Properties

Available Size●Plate (As Roll)●Plate (Heat Treatment)●Hot-rolled Sheet●Cold-rolled Sheet

Characteristic Properties●Physical Properties●Chemical Composition●Mechanical Properties●Paint durability●Paint Film Deterioration Tests●Impact Properties

●Abrasion Resistance●Weldability●Weld Joint Properties●Workability

Joint Materials●Welding Materials●Bolt Joints

32

NIPPON STEEL CORPORATION

Since 1959 when COR-TEN began to be marketed, this material has served as served as weathering steel (atmospheric corrosion-resistant steel).

COR-TEN has successfully overcome rust, steel’s most weakest, by capitalizing on its unique “rust cures rust” function.

When exposed to the atmosphere without painting, COR-TEN begins to rust in the same way as ordinary steel. But soon the alloying elements in COR-TEN cause a protective surface layer of fine-textured rust to form, thereby suppressing corrosion rate.

Capitalizing on this excellent property, COR-TEN can be used without painting, thereby nullifying the commonly held belief that “steel must be used with paint.”

But, if paint is applied to COR-TEN, the service life of the paint is prolonged compared to coatings applied to ordinary steel. Accordingly repainting costs are reduced.

Since its development in the U.S. in 1933, COR-TEN has been used in every field where steel is applied, such as bridges, railway vehicle and buildings. Recently, unpainted applications of COR-TEN are attracting attention as being especially suited for resource savings and environmental concerns.

Another growing application of unpainted COR-TEN is in conjunction with rust stabilization treatments on bridges, building exteriors and other structures.

In this way, COR-TEN helps to reduce lifecycle costs (LCC) and environmental burdens in a wide range of applications.

1 Features2Saving Maintenance Cost

Because COR-TEN has high weather resistance, it can be used without painting. Unpainted applications not only offer the economic advantage of reducing repainting costs; they also offer aesthetic benefits associated with the calming color of the protective rust.

While weather resistance depends on the product grade and the application environment, COR-TEN’s weather resistance is nearly 4~8 times that of ordinary steel.

Weather Resistance

COR-TEN is paintable in the same way as ordinary steel. In addition, even if a painting defect should occur, COR-TEN suppresses the progress of rust area and, accordingly, prolongs the service life of the paint, thereby reducing repainting costs.

Paint durability

While trace amounts of alloying elements such as copper (Cu) and chromate (Cr) are added to COR-TEN to ensure high weather resistance, the carbon content is lowered to provide appropriate weldability. Accordingly, COR-TEN can be welded using either manual, gas-shield or submerged arc welding. In addition, spot welding can be applied to thin-gauge COR-TEN.

Weldability

COR-TEN possesses workability (cold forming, hot forming and gas cutting) similar to ordinary steels of same strength.

Workability

Since 1959 when “COR-TEN” began to be marketed, more than 2.6 million tons of this material have been produced.

Reliability(2013 end)

54


When COR-TEN is exposed to the atmosphere, it develops an initial layer of rust as ordinary steel does. But, as time goes by, this early product gradually converts to a fine-textured rust (protective rust) that tightly adheres to the base metal, providing a protective layer that both protects the base metal and suppresses further corrosion.

Fig. 1 shows the results of exposure tests conducted in an industrial area. It can be seen from the figure that corrosion in COR-TEN is suppressed within 3 to 5 years.

Fig. 2 shows the results of exposure tests in

coastal areas. As can be seen in the figure, while the corrosion level of COR-TEN is lower progress than that of ordinary steel, corrosion continues to develop in COR-TEN for a long period. Accordingly, it is necessary to pay due care in the application of COR-TEN in coastal areas.

Fig. 3 shows the results of exposure tests in the U.S. The corrosion in both Japan and the U.S. show the same trend, but the corrosion levels in the U.S. is only about 1/3 to 1/2 that in Japan. This seems attributable to differences in temperature and humidity between Japan and the U.S.

Fig. 1 Exposure Tests in Industrial Areas

Fig. 2 Exposure Tests in Coastal Areas

Fig. 3-1 Exposure Tests in Industrial Areas in U.S. Fig. 3-2 Exposure Tests in Coastal Areas in U.S.

3■Exposure Test ResultsBecause a reliable accelerated test method is not available and because the alloying elements used in steel products and the effects of individual application environments are complicated, it is necessary to carry out long-term exposure tests using numerous test specimens in order to judge whether weather resistance is high or low.

COR-TEN was developed in 1933 as a result of long-term exposure tests using 30,000 or more test specimens. Since then, exposure tests and follow-up surveys of existing structures have been continued worldwide to further improve weather resistance. Extensive knowledge has been obtained on the performance characteristics that weathering steel should possess and on the environmental conditions required for weathering steel to fully demonstrate its unique weather resistance. The following offers a summary introduction of such knowledge.

It is necessary that steel products include the weather-resistant elements that which contribute to the formation of protective rustAs regards weather-resistant alloying elements, P, Cu, Cr and Ni are widely known. Further, Si, Mo, Ti and V are known as complementary elements used to improve weather resistance in combination with Cu and Cr.

Further, a multiplier effect can be obtained by appropriately combing the use of these elements, and thus higher weather resistance can be obtained by finding the optimum mix of elements from many experiments.

It is necessary for weathering steel to be subjected to repeated wet-dry cycles in the atmosphere in order to form protective rustAccordingly, when the surfaces of weathering steel are constantly submersed in water or wet earth, protective rust does not form. Consequently, the application environment such as this prevent the peculiar features of weathering steel from being fully utilized.

Further, protective rust is most likely to form in sections subjected to sunlight and rainfall, but is less likely to form in areas subjected to salts.

Because these environmental effects become clear when steel products are exposed to the atmosphere in an as-rolled state, it is necessary in unpainted applications of weathering steel to pay full attention not only to the select of COR-TEN steel but also to the purpose of its use and to the site where it is to be used.

Exposure Tests (without eaves)

Secular Changes in Rust Appearance

In the initial stage of application, COR-TEN shows a yellowish appearance. This is followed by a gradual change in the color of the protective rust from brown to a stable dark brown after one to two years in general application environments. Afterwards, the coloration shows no clear change except perhaps to a deeper dark brown.

（t×50×150mm）

曝露年数曝露年数

腐食量

腐食量

腐食量

腐食量

腐食量

腐食量

曝露年数曝露年数

曝露年数

A36（以後曝露せず）

曝露年数

Weather Resistance

TobataAmagasaki

Ashizuri-misakiSakaide Port (wharf) Weld joining material (Use of welding material exclusively used for SAW)

Kure Beach N.C. (The point 200 m from open sea)Keanmy N. J.

Co

rro

sio

n lo

ss (m

m)

Exposure years

Co

rro

sio

n lo

ss (m

m)

Exposure years

Co

rro

sio

n lo

ss (m

m)

Exposure years

Co

rro

sio

n lo

ss (m

m)

Exposure years

Co

rro

sio

n lo

ss (m

m)

Exposure years

Co

rro

sio

n lo

ss (m

m)

Exposure years

(No exposure after 8 years)

0.5 months 1.5 months 6 months 2 years 5 years 22 years 40 years

76


Unpainted use (Bare)4

Photo: Sep. 1977 (8 years after completion) Photo: May 1991 (22 years after completion) Photo: Jul. 2010 (41 years after completion)

Photo: Apr. 1973 (4 years after completion)

The unpainted application of COR-TEN not only offers economical advantages but, thanks to the calming color of the protective rust, it also demonstrates excellent aesthetic properties. Because of this, COR-TEN is applied in a wide range of fields such as buildings and monuments. Because the initial outflow of rust dirties the surrounding area, it is necessary to fully examine the application site and the purpose for using COR-TEN and to devise a structuring method.

Application Examples

Hokkaido Centennial Memorial Tower (Hokkaido)Photo: Oct. 1969 (under construction)

Kanno Museum of Art (Miyagi) Photo: May 2007 (1 year after completion)

N Corporation (Tokyo) Photo: Oct. 2005 (40 years after completion) La Chapelle des Pommiers (Normandy, France; �oor member; by Kyoji Takubo)Photo 1999 (at time of completion)

Univ. OKAYAMA Pref. Alumni House: June 2013 (at time of completion)

Shimane Museum of Ancient Izumo (Shimane) Photo: Oct. 2009 (3 years after completion) IRONHOUSE (Tokyo) Photo: Dec. 2009 (2 years after completion)

98


4COR-TEN can be applied without painting (in a bare state), thus reducing the cost of repainting and other repairs. However, there have been expressions of concern during the first year or two when the protective layer of fine-textured rust (protective layer) is forming. These concerns usually referred to adverse landscaping associated with the yellowish color of the initial rust and to the contamination of surrounding areas caused by the runoff of early-stage rust washed away by rainwater. As a result, there have been obstacles linked to the use of COR-TEN in spite of its superior economic advantages.

In order to solve these problems, supplementary rust stabilization treatment was developed.

In the case of Complementary Rust Stabilization Treatment, agents similar in color to rust have been selected on the premise that the agents would be converted to rust in the future. Recently, in order to meet requests for the free selection of colors that harmonize with surrounding colors, Complementary Rust Stabilization Treatment agents to which various colors can be applied.

Because the Complementary Rust Stabilization Treatment agents will eventually be converted to rust, there is a certain period when the color will cease, over time, to remain uniform. When countermeasures are required from a landscaping perspective, it is necessary to apply an easy restoration treatment for surface layer film.

Nagano Municipal Museum of Art(Nagano)

Photo: Jul. 2006(27 years after completion)

Nagano Municipal Museum of Art (Nagano) Photo: Aug. 1980 (8 months after completion)

No.2 Hozugawa Bridge (Kyoto) Photo: Sep. 2006 (18 years after completion)

Unpainted use (Complementary Rust Stabilization Treatment)

Ariake-tennis-no-mori (Tokyo) Photo: May 2007 (20 years after completion)

Viaduct Hokuriku Super-express (Niigata) Photo: Jun. 2005 (19 years after completion)

Arakawa Bridge (Tokyo): Landscape type Complementary Rust Stabilization Treatment (light blue) Photo: Jul. 2007 (6 years after completion)

Nagaragawa Baseball Stadium (Gifu) Photo: Oct. 2011 (22 years after completion)

Steel pier of Kitasaki Viaduct (Aichi): Landscape type Complementary Rust Stabilization Treatment (white) Photo: Jul. 2007 (7 years after completion)

World Hall (Hyogo) Photo: Mar. 2010 (26 years after completion)

1110


Painted use4When COR-TEN is painted, the required number of times that repainting must be conducted can be reduced.

This advantage is believed to result from the fact that, even when corrosion occurs in the base metal due to defects in the painted film or to pinholes, the corrosion progresses slowly and thus the occurrence of blistering and peeling of the paint film is reduced.

By making the most of this advantage, COR-TEN is applied in every field where steel is usedranging from buildings to railway vehicle, marine containers, storage tanks, industrial machinery and bridges.

Container

High-speed passenger ship (Setouchi Sea Line)

Gosha Inari Shrine (Aichi) Photo: Oct. 2005 (completion)

Flying Dome of Nihondaira Zoo (Shizuoka) Photo: Mar. 2011 (under constuction)

Jinbocho Theater (Tokyo) Photo: Dec. 2007 (0.5 years after completion)

Former Nippon Steel Head Of�ce (Tokyo) Photo: Oct. 2009 (40 years after completion)

Concrete mixer car

Arakawa Bridge (Tokyo)

Tomari Bridge (Okinawa) Photo: Nov. 2004 (19 years after completion)

Garbage truck (ShinMaywa Industries, Ltd.)

1312


CORQ is a cast metal product that has the features of COR-TEN and is used mainly for floor materials.

CORQ is produced and marketed by Okayama Casting Center (Tel: 8-86-277-5588).

CORQ™ is a registered trade name of Kyoji Takubo and NIPPON STEEL.

CORQ™ (Cast Metal) VINCOR™ 4

Application of CORQ in �oor Example of CORQ application

Library of Rikuzen Takada city “place of recreation” Photo: Sep. 2013 (completion)

Parts of CORQ

Gold Apple by Kyoji Takubo (University of The Sacred Heart) Photo: Jun. 2017

Exhibition in 2016 at the Tokyo Metropolitan Art Museum

Iiyama Church of the Resurrection

VINCOR (VINtage COR-ten) is a product to consider the initial color tone with a state of being aged from shipment.

VINCOR is sold by Chikumakozai Co., Ltd (Tel: 81-47-354-5721).

“Tamasora” by Noe AokiPhoto: Tadasu Yamamoto

“Stair in the Void” by Minoru Togashi (Yamagata) Photo: Jun. 2005 (4 years after completion)

Kotohiragu cafe & restaurant “Kamitsubaki” (Kagawa) Photo: 2009 (2 years after completion)

Yokohama Naka Ward Of�ce (Kanagawa) Photo: Oct. 2006 (23 years after completion)

Various Application Examples

Ind

ex s

how

ing

the

co

lor

tone

Lapse of time (years)

0.1

35

30

25

20

15

10

5

01 10 100

Partition wall in restaurant

■ By using the index numbers that have a high correlation with colors, the color tone is quantified and reproduced.

0.5 month after completion

5 months of completion

9 years after completion

1514


Steel Grades and Features Chemical Composition

Specification5●Because of its high

weather resistance, this grade is most suitable for unpainted application.

●Because of its high weather resistance, this grade can be used without painting.

●Because of its high weldability and notch toughness, this grade is recommended for use for welded structures.

●Featuring economical advantage, this grade is recommended for use with painting.

●Because of its high strength, NAW 490 offers a high wet abrasion resistance.

●Because of its high weather resistant, this grade can be used without painting.


●Because of its high weather resistance, this grade is most suitable for unpainted application.

●Because of its high weather resistance, this grade is most suitable for unpainted use.


●The mechanical properties excluding chemical composition conform to those in JIS SMA standards.

COR-TEN O

COR-TEN 490A/B/C

COR-TEN 570

NAW™ 400

NAW™ 490

NAW -TEN™12 -400A/B/C -490A/B/C -570

NAW -TEN™15 -400A/B/C -490A/B/C -570

COR-TEN A

COR-TEN B

COR-TEN B-QT

COR-TEN C

Highly weathering steel product

Unpainted specificationsFor welded structuresWeathering steel product

General weathering steel product

Ni-type highly weathering steel product





General weathering steel product

Ni-type highly weathering steelHighly weathering steel product



Hot-rolled sheet and plate：1.6≦t≦76Cold-rolled sheet：0.4≦t≦2.3Shape：6≦t≦38Bar：5.5≦t≦44

Hot-rolled sheet and plate：6≦t≦50Shape：6≦t≦38

Hot-rolled sheet and plate：6≦t≦50

Hot-rolled sheet and plate：1.6≦t≦12.7Shape：3.2≦t≦12.7

Hot-rolled sheet and plate：1.6≦t≦12.7Cold-rolled sheet：0.4≦t≦2.3Shape：3.2≦t≦12.7

Hot-rolled sheet and plate：6≦t≦100

●Sash, panel and other building exterior members

●Outer plate for rolling stock

●Marine container●Steel tower, etc

●Bridge●Steel frame, steel tower,

various platforms●Crane and other

industrial machinery●Flood gate●Low-pressure gas holder,

water tank and other large-size vessels

●Column, beam and outer plate of container

●Ready-mixed concrete car

●Small-capacity compressor tank

●Bridge●Steel tower●Building exterior member

●Sash, panel and other building exterior members

●Outer plate for rolling stock

●Marine container●Steel tower, etc

●Bridge●Steel frame, steel tower,

various platforms●Crane and other

industrial machinery●Flood gate●Low-pressure gas holder,

water tank and other large-size vessels

Steel grade Designation Applicable thickness range (mm) Feature Main applicationsC

≦0.12

≦0.12

≦0.12

≦0.19

≦0.19

≦0.18

≦0.17

≦0.17

≦0.035

≦0.035

≦0.050

≦0.05

≦0.05

≦0.05

≦0.035 ≦0.08≦0.035

≦0.035

≦0.035

Si

0.25～0.75

0.30～0.65

0.40～0.65

─

0.15～0.35

0.15～0.65

Mn

0.20～0.50

0.80～1.25

0.80～1.25

─

≦0.90

≦1.25

≦1.40

≦1.25

≦1.40

P

0.07～0.15

≦0.035

≦0.035

≦0.150

0.06～0.12

─

─

─

─

─

≦1.20

≦1.50

S Cu

0.25～0.55

0.30～0.40

0.30～0.40

0.20～0.40

0.25～0.50

0.50～1.00

0.30～0.50

Ni

≦0.65

0.05～0.30

0.05～0.30

─

─

0.70～1.70

2.50～3.50

Cr

0.30～1.25

0.45～0.65

0.45～0.65

≦0.40

─

Other elements

─

V:0.02～0.10

V:0.02～0.10

─

≦Ti:0.15

─

─

─

─

COR-TEN O

COR-TEN 490A/B/C

COR-TEN 570

NAW™ 400

NAW™ 490

NAW -TEN12 -400A/B/C

-490A/B/C -570

NAW -TEN15 -400A/B/C

-490A/B/C -570

0.25～0.75

0.30～0.65

0.30～0.65

0.20～0.50

0.80～1.25

0.80～1.35

0.07～0.15

≦0.04

≦0.04

0.25～0.55

0.25～0.40

0.25～0.40

≦0.65

≦0.40

≦0.40

0.50～1.25

0.40～0.65

0.40～0.70

─

V:0.02～0.10

V:0.04～0.10

─

─

COR-TEN A

COR-TEN B COR-TEN B-QT

COR-TEN C

Steel gradeDestination DesignationChemical Composition（%）

value

t≦12.7

t≦200

t≦100

t≦25

Hot-rolledsheet andplate

Notes:1) For unpainted uses, COR-TEN O, COR-TEN 490, COR-TEN 570, NAW-TEN™12 and NAW-TEN™15 are applied.2) Thicknesses or diameters other than those listed in the above table are subject to the agreement between the orderer and us.3) Bar includes bar-in-coil. But the diameter of bar-in-coil should be 32 mm or less.4) Regarding the grade other than those shown above, equivalent grades can be manufactured. Please consult us in advance.5) NAW™ and NAW-TEN™ are a registered trade name of NIPPON STEEL.6) Shapes are constantly not manufactured, so please consult us in advance concerning designations (only A and B) and size selection.

Notes:A parameter to weather-resistant alloying elements (ν value) is given by the following equation. Unit: mass%ν value=1/｛（1.0－0.16［C］）×（1.05－0.05［Si］）×（1.04－0.016［Mn］）×（1.0－0.5［P］）×（1.0＋1.9［S］）×（1.0－0.10［Cu］）×（1.0－0.12［Ni］）×

（1.0－0.3［Mo］）×（1.0－1.7［Ti］）｝C. Miki, A. Ichikawa, M. Ukai, S. Takemura, T. Nakayama and H. Kihira: Proposal of Weather-resistant Alloying Parameters and Weather Resistance Assessment Methods, Journal of Japan Society of Civil Engineers, No. 738/1-64, pp 271-281, July 2003

Fo

r d

om

estic

use

sF

or

ove

rsea

s us

es

─

1716


5 Mechanical Properties

ProductDesignation

Tension test ＊Bending test（180°bending）＊＊Impact test

Thickness or diametermm

Yield pointN/mm2

Tensile strengthN/mm2

Test pieceJIS

Thickness or diametermm

SymbolTest pieceJIS

Test temperature°C

Test pieceJIS

Charpy absorbed energyJInner radius

COR-TEN O

COR-TEN 490 A/B/C

COR-TEN 570

NAW 400

NAW 490

Cold-rolled sheet

Hot-rolled sheet and plate

Shape

Bar

Bar-in-coil


Shape



Shape

Cold-rolled sheet


Shape




t≦2.3

t≦20

20＜t≦38

38＜t

D≦38

38＜D

t≦16

16＜t≦40

40＜t

t≦16

16＜t≦40

40＜t

─

─

─

t≦16

16＜t≦40

40＜t≦100

t≦16

16＜t≦40

40＜t≦75

75＜t≦100

t≦16

16＜t≦40

40＜t≦75

75＜t≦100

315≦

355≦

325≦

295≦

325≦295≦360≦355≦335≦460≦450≦430≦

245≦

345≦

390≦

245≦235≦215≦365≦355≦335≦325≦460≦450≦430≦420≦

No.5

No.5

No.1A

No.1A

No.4

No.2

No.3

No.1A

No.4

No.5

No.4

No.5

No.1A

No.5

No.1A

No.4

No.1A

No.4

No.5

No.4

450≦

490≦

460≦

430≦

460≦430≦

490～610

570～720

400～510

460≦

490≦

400～540

490～610

570～720

─t≦5

5＜t

D≦32

32＜D

─

─

─────

─

─

─

──

─

──

B

C

─

─────A

B

C

A

B

C

─

──

─

──

0

0

－5

──────

0

─

0

－5

─No.3

No.1

No.2

─

─

No.3

No.1

─No.3

No.1

─

─

─

──

─

──

V-notch

Rolling direction

─────

V-notch

Rolling direction

──

─

──

27≦

47≦

47≦

──────

27≦47≦─

27≦

47≦

47≦

─1.0t

1.0t

1.5D

2.0D

─

─

1.0t

1.5t

─1.0t

1.5t

─

─

─

─t≦5

5＜t≦16

16＜t≦38

38＜t

D≦25

25＜D

t≦16

16＜t

40＜t

t≦16

16＜t

20＜t

t≦5

5＜t

t≦2.3

t＜6

6≦t

t≦16

16＜t

40＜t≦100

t≦16

16＜t

40＜t≦100

t≦16

16＜t

20＜t≦100

24≦22≦18≦

21≦

21≦23≦20≦23≦15≦19≦21≦19≦26≦20≦21≦17≦22≦22≦23≦17≦21≦23≦15≦19≦

21≦

19≦26≦

20≦

COR-TEN A

COR-TEN B

COR-TEN B-QT

COR-TEN C


≦12.7

≦100

100 over t≦125

125 over t≦200

≦100

≦25

345≦

345≦

315≦290≦485≦

415≦

485≦

485≦

460≦435≦

620/760

550≦

─────────

22≦18≦21≦18≦21≦21≦19≦21≦16≦

Elongation

Thickness or diameter mm Elongation %

＊＊＊50＊＊＊200＊＊＊50＊＊＊200＊＊＊50＊＊＊50＊＊＊50＊＊＊50＊＊＊200

＊Can be eliminated unless otherwise orderer specifies＊＊Applied to steel product with thicknesses more than12 mm

＊＊＊Test piece Gage length, mm

NAW-TEN12-400 A/B/C

NAW-TEN15-400 A/B/C

NAW-TEN12-490 A/B/C

NAW-TEN15-490 A/B/C

NAW-TEN12-570

NAW-TEN15-570

1918


Plate

Available Size6As Roll (products other than those listed in the table on page 18)

Notes:1) The figure in the table indicates the maximum length (m) of plate.2) The minimum length shall be 3 m.3) Regarding the applicable plate thickness, please refer to “Specifications” on page 13.

Notes:1) The figure in the table indicates the maximum length (m) of plate.2) The minimum length shall be 3 m.3) Regarding the applicable plate thickness, please refer to “Specifications” on page 13.

Heat Treatment (COR-TEN 570, COR-TEN B-QT, NAW-TEN12-570, NAW-TEN15-570)

Standard available sizes Standard available sizes

Thickness mm

Width　　 mm

15.023.0

21.0

15.023.0

22.5

20.0

18.0

15.023.0

20.0

17.5

16.0

15.023.0

21.5

18.5

16.0

14.5

13.0

15.023.0

19.5

17.0

15.0

13.0

12.0

15.023.0

19.5

17.0

15.0

13.0

12.0

15.023.0

18.0

15.515.513.5

12.5

11.5

15.023.0

17.0

14.5

12.5

11.5

15.023.0

15.5

13.5

12.0

11.5

15.023.0

14.5

12.5

11.0

15.023.0

14.0

12.0

10.5

9.5

8.5

15.023.0

13.0

11.5

10.0

9.0

8.5

15.0

23.0

22.021.020.019.018.014.0

12.5

11.0

9.5

8.5

15.023.0

22.021.020.019.018.017.013.0

11.5

10.0

9.0

8.5

15.0

23.0

21.020.019.018.017.016.012.0

11.5

9.5

8.5

15.023.0

22.020.019.018.017.016.015.012.0

11.0

9.0

8.5

15.023.0

22.021.019.018.017.016.015.014.011.0

10.5

9.0

8.5

15.023.0

22.020.019.018.017.016.015.014.011.0

10.0

8.5

8.0

over 6　789

101214161820222426283032343638404244464850525456586065707580859095

7 incl　89

101214161820222426283032343638404244464850525456586065707580859095

100

1000

1200or less

〜1200Over

1400or less

〜Thickness mm

Width　　 mm 1000

1200or less

〜1200Over

1400or less

〜1400

1600〜

1600

1800〜

1800

2000〜

2000

2200〜

2200

2400〜

2400

2600〜

2600

2800〜

2800

3000〜

3000

3200〜

3200

3400〜

3400

3600〜

3600

3800〜

3800

4000〜

4000

4200〜

4200

4400〜

4400

4500〜

6 16.020.021.0

22.0

23.0

22.5

20.0

16.020.021.0

22.0

23.0

22.5

20.0

18.0

16.020.021.0

22.0

23.0

20.0

17.5

16.0

16.020.021.0

22.0

23.0

20.5

19.018.016.0

14.5

16.020.021.0

22.0

21.5

18.5

16.0

14.5

13.0

16.020.021.0

22.0

19.5

17.0

15.0

13.0

12.0

16.020.021.0

22.0

18.0

15.5

13.5

12.5

11.0

16.020.021.0

22.0

21.020.017.0

14.5

12.5

11.5

10.5

16.020.021.0

22.0

21.0

20.019.015.5

13.5

12.0

10.5

9.5

16.020.021.0

22.0

21.020.019.018.0

14.5

12.5

11.0

10.0

9.0

12.014.015.020.0

21.0

22.0

21.020.019.0

17.016.014.0

12.0

10.5

9.5

8.5

20.021.0

22.0

20.019.018.0

17.016.015.013.0

11.5

10.0

9.0

8.0

21.0

22.0

20.019.018.017.0

16.015.0

12.5

11.0

9.5

8.5

7.5

21.022.0

20.019.018.017.016.0

15.014.0

11.5

10.0

9.0

8.0

7.0

21.0

22.0

21.019.018.017.016.0

15.014.0

13.011.5

9.5

8.5

7.5

6.5

21.0

22.0

21.019.018.017.016.0

15.013.0

12.011.0

9.0

8.0

7.0

6.5

21.0

22.0

21.020.019.018.017.016.015.014.013.0

12.0

10.5

9.0

7.5

7.0

6.0

21.0

22.0

21.020.018.017.016.015.014.0

13.0

12.0

10.0

8.5

7.5

6.5

6.0

over 6　789

101214161820222426283032343638404244464850525456586065707580859095

7 incl　89

101214161820222426283032343638404244464850525456586065707580859095

100

1400

1600〜

1600

1800〜

1800

2000〜

2000

2200〜

2200

2400〜

2400

2600〜

2600

2800〜

2800

3000〜

3000

3200〜

3200

3400〜

3400

3600〜

3600

3800〜

3800

4000〜

4000

4200〜

4200

4400〜

4400

4500〜

6

2120


Hot-rolled Sheet (COR-TEN O)

Cold-rolled Sheet

Thic

knes

s（m

m）

Thic

knes

s（m

m）

3.0

2.8

2.6

2.4

2.2

2.0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0

18

16

14

12

10

8

6

4

2

0

Width（mm）500 700 900 1100 1300 1500 1700 1900

Width（mm）400 600 800 1000 1200 1400 1600 1800 2000 2200

2.3×615

0.4×615

2.3×1275

0.8×12750.8×1260

0.6×12600.6×12500.5×1200

0.4×1200

18.0×600 18.0×1200

15.0×1690

3.2×1690

2.0×1690

18.0×1690

1.4×16001.2×13501.2×600

18.0×600

3.2×600

Hot-rolled Sheet and Cold-rolled Sheet6 7 Physical Properties (Example)

Characteristic Properties

Black figure: Available size range of hot-rolled coilBlue figure: HCL available size range (available length: 1800~12700 mm)

※The available size range differs depending on the steel grade and size. Please inquire us for every lot of orders.

Legend:

＜＞: Value of “mild steel (C: 0.12~0.20%) specified in Handbook on Mechanical Engineering (The Japan Society of Mechanical Engineers)

COR-TEN O

NAW 490

19.3～20.7×104

20.5×104

＜20.74×104N/mm2（18˚C）＞

＜11.16～11.28×10－6/ ˚C（20˚C）＞

＜0.1136～0.1146（20˚C）＞

＜43～52kcal/m hr˚C（20˚C）＞

＜13.7～15.8μΩ cm（20˚C）＞

COR-TEN O

NAW 490

Temperature range (from room temperature) Up to 100˚C

10.5

─

Up to 200˚C

11.8

─

Up to 300˚C

12.8

13.0

Up to 400˚C

13.4

─

Up to 500˚C

13.5

─

Up to 600˚C

13.6

13.8

Temperature（˚C）

Specific heat

50

0.105

100

0.111

150

0.122

200

0.105

250

0.128

300

0.134

350

0.140

400

0.145

450

0.150

500

0.164

550

0.176

600

0.198


100

200

300

400

500

600

cal/cm sec˚C

1.34×10－1

1.18×10－1

1.05×10－1

0.94×10－1

0.86×10－1

0.80×10－1

kcal/m hr˚C

48.2

42.5

37.8

33.8

31.0

28.8


Resistivity（μΩ cm）

20

20.3

100

23.8

200

29.4

300

38.5

400

50.4

500

63.6

600

79.2

Elastic Modulus (Unit:N/mm2)

Coefficient of Thermal Expansion (Unit:×10-6/˚C)

Specific Heat (NAW 490)

Thermal Conductivity (NAW 490)

Electrical Resistance (NAW 490)

2322


7

Fatigue Test Results High-temperature Tension Test Results Creep Rupture Strength (105 hours, estimated)

Chemical Composition, Mechanical Properties (Example)

Chemical Composition and Tensile Test Values

0.08

0.08

0.08

0.08

0.13

0.15

0.15

0.09

0.09

0.09

0.07

0.08

0.45

0.43

0.43

0.44

0.26

0.45

0.46

0.35

0.36

0.35

0.18

0.20

0.38

0.40

0.41

0.41

1.01

0.96

0.96

1.21

1.19

1.22

0.55

0.62

0.115

0.094

0.096

0.095

0.008

0.019

0.018

0.016

0.015

0.014

0.043

0.066

0.12

0.17

0.17

0.16

0.11

0.12

0.11

0.12

0.13

0.12

─

─

─

0.28

0.28

0.28

0.28

0.32

0.33

0.32

0.32

0.33

0.34

0.28

0.27

0.60

0.59

0.59

0.61

0.46

0.47

0.46

0.50

0.53

0.52

0.35

─

─

─

─

─

─

0.03

0.06

0.06

0.04

0.04

0.03

─

─

─

─

─

─

─

─

─

─

─

─

─

─

0.03

345

404

392

382

395

385

385

570

540

540

305

432

433

500

536

524

520

530

520

520

661

640

640

450

547

535

33

35

27

26

26

27

33

36

28

27

36

31

34

No.5

No.5

No.1A

No.1A

No.1A

No.1A

No.4

No.5

No.4

No.4

No.5

No.5

No.5

0.018

0.005

0.005

0.004

0.006

0.005

0.005

0.006

0.005

0.004

0.018

0.004

1.2

3.2

6.0

9.0

12

25

42

19

25

32

2.0

2.3

8.0

Cold-rolled sheet






COR-TEN O

COR-TEN 490

COR-TEN 570

NAW 400

NAW 490

Designation Product Thicknessmm Yield point

N/mm2


Elongation％

Test pieceJIS

C Si Mn P S Cu Ni Cr V Ti

Tensile test valueChemical composition（％）

●Loading type: Pulsating tension●Minimum load: 20N/mm2

●Frequency: 500c.p.m.●Test piece condition: As black scaled

Max

imum

cyc

lic s

tres

s

Str

ess

Str

ess

Cyclic numbers up to fracture Test temperature Temperature

Tensilestrength

0.2% offsetyield strength

2524


7

No Phosphate Treatment

Bonderizing Primer

Exposure Test Results for Painted Steel Pieces

■Corrosion Tests for COR-TEN below Paint Film

COR-TEN, ordinary carbon steel and 0.2% Cu steel were painted and exposed to the atmosphere for one year. The results of tests comparing the corrosion rates of the metal beneath the respective paint films are shown in the table at the right.

In the test, the surfaces were prepared with a phosphate treatment, given a primer undercoat, and were top-coated using an urea-type alkyd coating. Following this, the identical test specimens were given the same flaw, a diagonal break in the paint film, after which they were exposed to the atmosphere. Photos at right show the test conditions in the 8th month. It is clear from the test results that COR-TEN exhibits high performances in every coating condition, and that, the corrosion rate of COR-TEN is 5 times good on than that of 0.2% Cu steel and 70 times good than that of ordinary carbon steel.

■Exposure Tests for Painted Materials in Industrial Areas

Atmospheric exposure tests were conducted in Amagasaki and Himeji (Hirohata) on test specimens that were given three layers of zinc oxide paint over a wash primer and then given an artificial flaw. The test results are shown in the photos at right.

It is understood from the photos that there is a great difference between COR-TEN and ordinary steel vis-à-vis rust originating from an artificial flaw.

●Ordinary steel ●0.2%Cu steel ●COR-TEN

●Ordinary steel ●0.2%Cu steel ●COR-TEN

●4-year exposure (Amagasaki) ●8-year exposure (Hirohata)

SS 400 COR-TEN 490 SS 400 COR-TEN 490

Using COR-TEN O, Cu-containing steel and ordinary carbon steel in industrial, semi-rural and coastal areas, H.R. Copson and C.P. Larrabee jointly surveyed paint deterioration and corrosion rates over an 8- year span. The results of the survey are shown below. The test results show that the higher the corrosion resistance of the steel grade, the longer the service life of the paint film. The service life of paint applied to COR-TEN is expected to be 1.5 times (2 times on average) greater than for other steel materials.

Paint durability (Example) Paint Film Deterioration Tests (Example)

Chemical Composition

Corrosion Test Results for Painted Test Pieces: Number of Years of Paint Deteriorationb)

Notes:a) The test piece of cold-rolled carbon steel caused corrosion from its rear side, and pitting occurred in 8 years, leading to nearly damage.b) When the breach of paint coatings occurs on the 2% of the sheet surface, including the cut edges, it is defined as deterioration of painting.c) Paint breach: Less than 2% even when 8 years have passedd) Rust below paint film caused discoloration, and the film was not breached.

Steel gradeC Si Mn P S Cu Ni Cr

Cold-rolled sheet


Cold-rolled sheet


Cold-rolled sheet


0.03

0.17

0.05

0.16

0.08

0.09

0.003

0.027

0.003

0.016

0.65

0.60

0.27

0.40

0.40

0.25

0.30

0.37

0.009

0.013

0.004

0.006

0.09

0.10

0.020

0.034

0.016

0.024

0.020

0.022

0.03

0.04

0.28

0.21

0.41

0.37

0.02

0.02

0.07

0.04

0.48

0.46

0.02

0.05

0.03

0.02

0.85

0.92

Carbon steel

Cu-containing steel

COR-TEN O

Carbon steel

Cu-containing steel

COR-TEN O

2.0

4.5

4.5

2

c）c）

3.0

4.0

4.5

2

c）c）

Hot rolling

Cold rolling

2.5

5.0

c）c）c）c）

2.0

5.0

c）c）c）c）

3.0

8.0

c）c）c）c）

2.0

2.0

c）c）c）c）

4.0

5.0

6.5

d）d）d）

c）c）c）c）c）c）

4.0

5.0

c）d）d）d）

Carbon steel

Cu-containing steel

COR-TEN O

Chemical Composition（%）

Steel grade By rolling Zincchromate

primer coating

Red-lead

primer coating

Iron oxide

primer coating

Zincchromate

primer coating

Red-lead

primer coating

Iron oxide

primer coating

Zincchromate

primer coating

Red-lead

primer coating

Iron oxide

primer coating

Kearny, New Jersey(Industrial area)

South Bend, Pennsylvania(Semi-rural area)

Kure Beach, North Carolina(Coastal area, 800 ft from sea)a)

Corrosion Test Results for Painted Test Pieces: Rust Occurrence Rate after Lapse of 8 Years

Carbon steel

Cu-containing steel

COR-TEN O

Carbon steel

Cu-containing steel

COR-TEN O

50

13

3

50

0

0

90

50

10

25

Trace

0

Hot rolling

Cold rolling

100

90

1

98

Trace

0

90

10

Trace

0.3

0.1

0

25

3

Trace

0

0

Trace

99

10

0

0.1

Trace

0

60

30

Trace

0d）

0d）

0d）

Trace

Trace

Trace

0

0

0

100

50

Trace

100

80

0d）

Steel grade By rolling Zincchromate

primer coating

Red-lead

primer coating

Zincoxide

primer coating

Zincchromate

primer coating

Red-lead

primer coating

Iron oxide

primer coating

Zincchromate

primer coating

Red-lead

primer coating

Iron oxide

primer coating

Kearny, New Jersey(Industrial area)

South Bend, Pennsylvania(Semi-rural area)

Kure Beach, North Carolina(Coastal area, 800 ft from sea)a)

Corrosion Test Results (Kure Beach N.C. 180 ft site, 365 days)

Painting condition

Bare material

Direct painting on substrate surface

X marking on the above surface

Painting after phosphate treatment

X marking on the above painting

Only primer coating on substrate surface

Primer coating after phosphate pretreatment

212

55

97

26

40

210

133

Ordinary steel

13

1

1

0.3

0.3

7

6

COR-TEN

16

55

97

87

133

30

22

MagnificationCorrosion rate mg/100cm2/day

2726


Impact Properties and Abrasion Resistance (Example) Weldability (Example)7Taper Hardness Test Results

Y-groove Weld Cracking Test Results (COR-TEN 490)

Steels containing P─such as COR-TEN O, NAW 400 and NAW 490－are likely to suffer hot cracking during welding and are thus not recommended for use in welded structures requiring heavy-gauge members that are ≧13 mm in thickness.

For welded structure applica-tions, it is recommended to adopt NAW K-400, COR-TEN 490 and COR-TEN 570 having high weld-ability. These products are low in hardenability, highly resistant to weld cracking and offer high joint performance.

L-direction C-direction

Impact PropertiesCharpy Transition Curve (V-notch (Sub-size test piece 5×10 mm in plate thickness of 6 mm))

Abrasion ResistanceAbrasion Resistance to Wet Sand

Ab

sorb

ed e

nerg

y（J）

Brit

tle fr

actu

re ra

tio（%

）

Test temperature（˚C）（Plate thickness） COR-TEN O（6mm） NAW490（6mm） COR-TEN 490（20mm） COR-TEN570（20mm）

Ab

rasi

on

loss

Number of rotation（　×104）

（　）: HB hardnessTest piece　　　10φ×120mmRevolution rotation number　1,000/hrRevolution radius 180mmAutorotation number 5,000/hr

Welding direction Arc strike

Arc strike

Plate thickness（mm）

Plate thickness（mm）

Har

dnes

s of

hea

t-af

fect

ed z

one

Cooling rate at 540˚C（˚C/sec）

Cooling time from 800˚C to 500˚C（sec）

Plate thickness : 19mm Plate thickness : 38mm

Plate thickness : 42mmPlate thickness : 32mm

Root cracking

Section cracking

Surface cracking

Cra

ck o

ccur

renc

e ra

tio（

%）

Cra

ck o

ccur

renc

e ra

tio（

%）

Cra

ck o

ccur

renc

e ra

tio（

%）

Cra

ck o

ccur

renc

e ra

tio（

%）

Initial temperature of plate（˚C）




2928


Weld Joint Hardness Distribution

■COR-TEN 490 (25mm) (SMAW, As-welded) ■COR-TEN 490 (25mm) (SAW, As-welded)

Charpy Impact Test Results for Weld Joint of COR-TEN 490

■Manual weld joint (25mm)

7 Weld Joint Properties (Example) Workability (Example)

Bri

ttle

fra

ctur

e ra

tio（

%）

Ab

sorb

ed e

nerg

y（J）

Bri

ttle

fra

ctur

e ra

tio（

%）

Ab

sorb

ed e

nerg

y（J）

Vic

kers

har

dne

ss（H

v10k

g）

Vic

kers

har

dne

ss（H

v10k

g）

Measurementline

●Welding rod : CT-16 4mmφ●Current : 160～240Amp●Voltage : 26～33Volt●Welding speed : 10～30cm/min●Initial temperature of plate: 　Room temperature

●Welding material : CT-350×Y-D●Current : 800A●Voltage : 33V●Welding speed : 28cm/min●Initial temperature of plate: 　Room temperature

Center

Test temperature（˚C） Test temperature（˚C）

Center

Base metal Base metalWeld metal

Bond

HAZ

Weld metal

Weld metal

Base metal

Basemetal

Basemetal

HAZ HAZHAZ HAZ

Measurementline

●Preheating temperature : 50˚C　Interpass temperature : 100˚C●Welding rod : CT-16 4.0φ●Current : 180A●Voltage : 24V●Welding speed : 13cm/min

●Preheating temperature : 　Room temperature　Interpass temperature : 150˚C●Welding rod : CT-350×Y-D（4.8φ）●Current : 800A●Voltage : 33V●Welding speed : 28cm/min

■Submerged arc weld joint (25mm)

Plate thickness

≦1.6

over 1.6, ≦6.0

over 6.0, ≦20

Minimum inner bending radius

1t

2t

3t

■Cold BendingIt is considered that thin-gauge plates of COR-TEN O and NAW 490 are most commonly used with cold bending. When cold bending is applied under the conditions shown in the table below, favorable results can be obtained.

■Drilling and MachiningWhen drilling and machining COR-TEN 490 and COR-TEN 590, tool damage is reduced and fine finishes are made possible using fabrication speeds slightly lower than those for SM490 and SM570. The standard applicable fabrication speeds are 2/3 the speed used with SS400 for drilling and 3/7 the speed for machining.

■Hot WorkingAside from COR-TEN 570, all grades of COR-TEN steel can be hot-worked in the same way as ordinary carbon steel. Because COR-TEN 570 is quenched and tempered, it undergoes changes in material quality and suffers drops in yield point and tensile strength when hot working is applied at temperatures higher than the tempering temperature. It is recommended that hot working be conducted at temperatures of 600˚C or lower.

■CuttingBoth shear cutting and gas cutting can be applied to COR-TEN in the same way as ordinary steel products. In applying gas cutting to COR-TEN 570, the hardness slightly increases near by cutting area. This level of increase in hardness does not exert any appreciable effect on the subsequent fabrication processes, but when preheating and postheating are applied before and after gas cutting, the subsequent cold working is favorably attained.

■Spot Heating and Linear Heating for Stress Relief

Stress relief of COR-TEN can be undertaken by means of spot heating and linear heating. When COR-TEN is heated to relieve stress in the same way as ordinary steel, no deterioration in material quality occurs.

When the heating temperature is elevated beyond 800˚C, due care should be taken because the material strength and surface hardness increase while toughness tends to decrease.

It is recommended that COR-TEN 570 be treated in the same way as SM570.

New welding materials brand show in p30.

3130


Welding Materials Bolt Joints

Joint Materials8The following welding materials for use with COR-TEN are prepared by NIPPON STEEL WELDING & ENGINEERING CO.,LTD.

■Exposure Test Results for Weld Joints

Manual welding test specimens were prepared for COR-TEN 490 and WEL-TEN™ 590 in order to compare the rates of corrosion between these two specimens and base metal specimens (no joints)－the results are shown in the figure on the right. The test results show that the weld joints of both COR-TEN 490 and WEL-TEN 590 have weather resistance similar to the base metal.WEL-TEN™ is a registered trade name of NIPPON STEEL.

Co

rro

sio

n lo

ss (m

m)

Exposure year

C

0.20～0.25

0.20～0.25

Si

0.15～0.25

0.15～0.25

Mn

0.70～0.90

0.40～0.60

P

≦0.030

≦0.030

S

≦0.030

≦0.030

Cu

0.30～0.50

0.30～0.50

Ni

0.30～0.50

2.50～3.50

Cr

0.60～0.80

─

Al

0.040～0.080

─

Mo

─

0.15～0.25

B

0.0010～0.0030

0.0010～0.0025

Class by mechanical propertyYield strengthN/mm2

900≦


1000～1200

Elongation%

14≦

Reduction of area%

40≦

Chemical compositionMaterial

F10TW（S10TW）F10TMR（S10TMR）

Class by mechanicalproperty Hardness

95HRB～35HRC

Guaranteed load

Same as minimumtension load of bolt

F10WF10MR

Class by mechanicalproperty Hardness

35～45HRCF35WF35MR

Class by mechanical propertyM16

157

157

M20

245

245

M22

303

303

M24

353

353

Hardness

27～38HRC

─

F10TW（S10TW）F10TMR（S10TMR）Effective section of bolt（mm2）

　

NWB110

NWB110-MR

Minimum tension load kN

■Chemical Composition (Standard Values)

■Applicable sizes: M16～M24

■Mechanical Properties (Standard Values)

Mechanical Properties of Test Pieces

Welding Materials and Examples of Characteristic Properties

Mechanical Properties of Bolts

Note: The figure in the table shows the minimum tension load that can withstand up to the bolt fracture when the tension test is conducted by inserting the wedge into the bearing surface of bolt and on the condition of no breakage of bolt head.

Note: The tension test is conducted using JIS Z2201 No. 4 test piece.

（mass%）

Bolts

Nuts

Washers

(1) Weather-resistant High-strength BoltsF10TW and S10TW, and F10TMR and S10TMR are available as high-strength bolts for use with weathering steel. It is recommended that F10TMR and S10TMR be used with the NAW-TEN series.

For more details, inquire at NIPPON STEEL BOLTEN CORPORATION (Phone: 81-6-6682-3261).

Inquiry: NIPPON STEEL WELDING & ENGINEERING CO.,LTD. Shingu Bldg., 4-2 Toyo 2-chome, Koto-ku, Tokyo 135-0016 JAPAN TEL.+81-3-6388-9000 FAX.+81-3-6388-9160 URL.www.weld.nipponsteel.com

Weldability is excellent in all positions. For the welding of a thin plate less than 9mm.

Extra low hydrogen type electrode for welding of medium and thick plates in all positions. Crack resistance and mechanical properties are excellent.Diffusible hydrogen content is extremely low and weld metal shows excellent crack resistance. Weldability is excellent in all positions.Diffusible hydrogen content is extremely low and weld metal shows excellent crack resistance. Weldability is excellent in horizontal fillet welding.GMA welding wire for all positions. Welding of atmospheric corrosion resisting steel (P specifications) for various structural works.GMA welding wire for all positions to be used with CO2 shield gas. Weldability is good in wide current range.

Extra low hydrogen type electrode in all positions. It assures excellent weldability, X-ray properties, crack resistance and mechanical properties.Diffusible hydrogen content is extremely low and weld metal shows excellent crack resistance. Weldability is excellent in all positions.Diffusible hydrogen content is extremely low and weld metal shows excellent crack resistance. Weldability is excellent in horizontal fillet welding.GMA welding wire for all positions to be used with CO2 shield gas. Weldability is good in wide current range.

For flat fillet and butt welding.

For flat fillet and butt welding.

For fillet welding.

For fillet and butt welding.(vE0˚C : more than 27J)

For fillet and butt welding.(vE0˚C : more than 47J)

※1 NSSW FGC-55 is P specifications (Paint). Other materials are W specifications.※2 NSSW NF-810 is SAW flux for COR-TEN490B. NSSW NF-820 is SAW flux for COR-TEN490C.　　● Regarding the welding materials for NAW-TEN series, refer to the catalog prepared exclusively for the series.

SMAW

FCAW

GMAW

SAW

SMAW

FCAW

GMAW

SAW

Welding methodDesignation Brand name Characteristics

NSSW CT-03Cr

NSSW CT-16Cr

NSSW SF-50W

NSSW SM-50FW

NSSW FGC-55 (P specifications) ※1

NSSW YM-55W

NSSW YF-15B × NSSW Y-CNCW

NSSW NF-810 × NSSW Y-CNCW ※2

NSSW NF-820 × NSSW Y-CNCW ※2

NSSW CT-60Cr

NSSW SF-60W

NSSW SM-60FW

NSSW YM-60W

NSSW YF-15B × NSSW Y-60W

NSSW NF-820 × NSSW Y-60W

COR-TEN 570

COR-TEN B-QT

COR-TEN 490

COR-TEN B

500

500

500

510

460

580

510

480

490

520

630

540

540

520

540

570

560

580

590

570

630

600

600

570

610

685

620

640

630

640

29

30

26

27

25

27

27

23

27

25

22

23

26

29

25

0

0

0

0

0

0

0

0

0

−18

−5

−5

−5

−5

−5

110

240

100

74

180

90

120

47

76

180

115

70

110

88

66

Tensile property Impact propertyYieldpoint(Mpa)

Tensilestrength(Mpa)

Elongation

(%)

Temperature

(˚C)

vE (J)

Notes:

COR-TEN 490–CT-16CT-16 is conventional welding material(Production discontinuation)WEL-TEN 590–NSSW L-60

Base metal

Weld joint(welding material)

3332


MEMO8■Characteristic Performance TestsWeather Resistance of High-strength BoltsThe exposure test results (1 year) for various kinds of high-strength bolts are shown in the figure below. It is understood from the figure that these bolts demonstrate high characteristic performances.

Weather Resistance of Various High-strength Bolts (1st year)

16

14

12

10

8

6

4

2

0S40C SAE1024B SCM3 NWB110

Tightening Exposure Delayed Fracture TestsMain points of the test

●Bolt size……………………………………………………M22×85

●Tightening plate……………………………………………WT60R

●Tightening outline…Nut rotation angle method（0.9N max.）; Plastic range tightening

●Exposure site……………………………………Minoshima Coast

Fracture condition （as of December 31, 1992）

Bolt

Weather-resistant high-strength bolt

Date to start exposure

November 28, 1978

Number of test piece

10

Fracture number

0

Delayed Fracture StrengthHigh-humidity atmospheric delayed fracture tests and tightening exposure delayed fracture tests were conducted to survey the delayed fracture strength.

High-humidity Atmospheric Delayed Fracture TestsMain points in the test

●Test method…Round bar notch tension test (stress concentration coefficient 4.5）●Load stress…………………………………………………0.9N.T.S

●Atmosphere…Saturated vapor atmosphere(humidity:36～37˚C)

Test results

Delayed fracture time （hrs）Bolt

Weather-resistanthigh-strength bolt

Ordinary steelhigh-strength bolt

1264

200 600 1000 1400 1800

1153

13961202

1483

試験期間（年）（試料は所定の強度レベルに熱処理したもの）

腐食減量（gr/dm2 ）

14

12

10

8

6

4

2

0.5　　　　1　　　　1.5　　　　2　　　　2.5　　　　0.5

Secular Changes

腐食減量　gr/dm2

Co

rro

sio

n ra

te（g

r/d

m2 ）

腐食減量　gr/dm2

Co

rro

sio

n ra

te（g

r/d

m2 ）

Exposure period (year)(Test piece: Heat-treated to prescribed strength level)

Industrial areaCoastal industrial area (lapse of 1 year)

Industrial area

Carbon steel（S40C）

Ordinary steelhigh-strength bolt

Weather-resistanthigh-strength bolt

Bolt Joints

steel cor-ten · 8 9 nippon steel corporation 4 cor-ten can be applied without painting (in a bare...

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