types of steel

7/24/2019 Types of Steel

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Carbon steelFrom Wikipedia, the free encyclopedia

Steelsand other ironcarbon alloy phases

Ferrite

Austenite

Cementite

Graphite

Martensite

Microstructures

Spheroidite

Pearlite

Bainite

Ledeburite

Tempered martensite

Widmanstatten structures

Classes

Crucible steel

Carbon steel

Spring steel

Alloy steel

Maraging steel

Stainless steel

Weathering steel

Tool steel

Other iron-based materials

Cast iron

Gray iron

White iron

Ductile iron

Malleable iron

Wrought iron

T

!
https://en.wikipedia.org/wiki/Steelhttps://en.wikipedia.org/wiki/Ferrite_(iron)https://en.wikipedia.org/wiki/Austenitehttps://en.wikipedia.org/wiki/Cementitehttps://en.wikipedia.org/wiki/Graphitehttps://en.wikipedia.org/wiki/Martensitehttps://en.wikipedia.org/wiki/Microstructurehttps://en.wikipedia.org/wiki/Spheroiditehttps://en.wikipedia.org/wiki/Pearlitehttps://en.wikipedia.org/wiki/Bainitehttps://en.wikipedia.org/wiki/Ledeburitehttps://en.wikipedia.org/wiki/Tempering_(metallurgy)#Physical_processeshttps://en.wikipedia.org/wiki/Widmanstatten_patternhttps://en.wikipedia.org/wiki/Crucible_steelhttps://en.wikipedia.org/wiki/Spring_steelhttps://en.wikipedia.org/wiki/Alloy_steelhttps://en.wikipedia.org/wiki/Maraging_steelhttps://en.wikipedia.org/wiki/Stainless_steelhttps://en.wikipedia.org/wiki/Weathering_steelhttps://en.wikipedia.org/wiki/Tool_steelhttps://en.wikipedia.org/wiki/Cast_ironhttps://en.wikipedia.org/wiki/Gray_ironhttps://en.wikipedia.org/wiki/White_ironhttps://en.wikipedia.org/wiki/Ductile_ironhttps://en.wikipedia.org/wiki/Malleable_ironhttps://en.wikipedia.org/wiki/Wrought_ironhttps://en.wikipedia.org/wiki/Template:Steelshttps://en.wikipedia.org/wiki/Template:Steelshttps://en.wikipedia.org/wiki/Template_talk:Steelshttps://en.wikipedia.org/wiki/Template_talk:Steelshttps://en.wikipedia.org/w/index.php?title=Template:Steels&action=edithttps://en.wikipedia.org/w/index.php?title=Template:Steels&action=edithttps://en.wikipedia.org/wiki/Ferrite_(iron)https://en.wikipedia.org/wiki/Austenitehttps://en.wikipedia.org/wiki/Cementitehttps://en.wikipedia.org/wiki/Graphitehttps://en.wikipedia.org/wiki/Martensitehttps://en.wikipedia.org/wiki/Microstructurehttps://en.wikipedia.org/wiki/Spheroiditehttps://en.wikipedia.org/wiki/Pearlitehttps://en.wikipedia.org/wiki/Bainitehttps://en.wikipedia.org/wiki/Ledeburitehttps://en.wikipedia.org/wiki/Tempering_(metallurgy)#Physical_processeshttps://en.wikipedia.org/wiki/Widmanstatten_patternhttps://en.wikipedia.org/wiki/Crucible_steelhttps://en.wikipedia.org/wiki/Spring_steelhttps://en.wikipedia.org/wiki/Alloy_steelhttps://en.wikipedia.org/wiki/Maraging_steelhttps://en.wikipedia.org/wiki/Stainless_steelhttps://en.wikipedia.org/wiki/Weathering_steelhttps://en.wikipedia.org/wiki/Tool_steelhttps://en.wikipedia.org/wiki/Cast_ironhttps://en.wikipedia.org/wiki/Gray_ironhttps://en.wikipedia.org/wiki/White_ironhttps://en.wikipedia.org/wiki/Ductile_ironhttps://en.wikipedia.org/wiki/Malleable_ironhttps://en.wikipedia.org/wiki/Wrought_ironhttps://en.wikipedia.org/wiki/Template:Steelshttps://en.wikipedia.org/wiki/Template_talk:Steelshttps://en.wikipedia.org/w/index.php?title=Template:Steels&action=edithttps://en.wikipedia.org/wiki/Steel


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Carbon steelis steelin which the main interstitialalloyingconstituent is carbonin the range of 0.122.0%. he!merican "ron and #teel "nstitute$!"#" defines that&

#teel is considered to be carbon steel

when no minimum content is specified or re'uiredfor chromium,cobalt, molybdenum, nickel,niobium,titanium, tungsten,(anadiumor )irconium, or any other element to be added to obtain a desired alloying effect* when the specified minimum for copper does not e+ceed 0.0 percent* or when the ma+imum content specified for any of the following elements does not e+ceedthe percentages noted&manganese1.-,silicon0.-0, copper0.-0./1

he term carbon steel may also be used in reference to steel which is not stainless steel*in this use carbon steel may include alloy steels.

!s the carbon percentage content rises, steel has the ability tobecome harderandstrongerthroughheat treating* howe(er, it becomes less ductile.egardless of the heat treatment, a higher carbon content reduces weldability."n carbonsteels, the higher carbon content lowers the melting point./2

Contents

/hide

1 ype

o 1.1 3ild and low4carbon steel

o 1.2 5igher4carbon steels

2 ypes

o 2.1 6ow4carbon steel

o 2.2 3edium4carbon steel

o 2.7 5igh4carbon steel $!#3 70

o 2. 8ltra4high4carbon steel

7 5eat treatment

9ase hardening

Forging temperature of steel

- #ee also

: eferences

;


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3ild steel/clarification needed, also known as plain-carbon steel, is now the most common form of steelbecause its price is relati(ely low while it pro(ides material properties that are acceptable formany applications. 6ow4carbon steel contains appro+imately 0.00.1% carbon /1making itmalleable and ductile. 3ild steel has a relati(ely low tensile strength, but it is cheap andeasy to form* surface hardness can be increased through carburi)ing./7

"t is often used when large 'uantities of steel are needed, for e+ample asstructural steel.he density of mild steel is appro+imately :.; g=cm7$:;0 kg=m7or 0.2; lb=in7/andthe >oung?s modulusis 210 @Aa $70,000,000 psi./

6ow4carbon steels suffer from yield-point runoutwhere the material has twoyield points. hefirst yield point $or upper yield point is higher than the second and the yield dropsdramatically after the upper yield point. "f a low4carbon steel is only stressed to some pointbetween the upper and lower yield point then the surface may de(elop 6Bder bands./-6ow4carbon steels contain less carbon than other steels and are easier to cold4form, makingthem easier to handle. /:

Higher-carbon steels/edit

9arbon steels which can successfully undergo heat4treatment ha(e a carbon content in therange of 0.701.:0% by weight. race impurities of (arious otherelementscan ha(e asignificant effect on the 'uality of the resulting steel. race amounts of sulfurin particularmake the steelred4short, that is, brittle and crumbly at working temperatures. 6ow4alloycarbon steel, such as!7-grade, contains about 0.0% sulfur and melts around 1,2-1,7; C9 $2,DD2,;00 CF./;3anganeseis often added to impro(e thehardenabilityof low4carbon steels. hese additions turn the material into a low4alloy steelby some definitions,but!"#"?s definition of carbon steel allows up to 1.-% manganese by weight.

Types/editSee also: SAE steel grades

9arbon steel is broken down into four classes based on carbon content&

Low-carbon steel/edit0.040.2% carbon content.

Medium-carbon steel/edit

!ppro+imately 0.200.-% carbon content./1


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"ron4carbonphase diagram,showing the temperature and carbon ranges for certain types of heat treatments.

Main article: Heat treatment

he purpose of heat treating carbon steel is to change the mechanical properties of steel,usually ductility, hardness, yield strength, or impact resistance. ote that the electrical andthermal conducti(ity are only slightly altered. !s with most strengthening techni'ues forsteel,>oung?s modulus$elasticity is unaffected. !ll treatments of steel trade ductility for

increased strength and (ice (ersa. "ron has a higher solubility for carbon inthe austenitephase* therefore all heat treatments, e+cept spheroidi)ing and processannealing, start by heating the steel to a temperature at which the austenitic phase cane+ist. he steel is then 'uenched $heat drawn out at a high rate causing cementite toprecipitate and finally the remaining pure iron to solidify. he rate at which the steel is cooledthrough theeutectoidtemperature affects the rate at which carbon diffuses out of austeniteand forms cementite. @enerally speaking, cooling swiftly will lea(e iron carbide finelydispersed and produce a fine grained pearlite$until the martensitecritical temperature isreached and cooling slowly will gi(e a coarser pearlite. 9ooling a hypoeutectoid steel $lessthan 0.:: wt% 9 results in a lamellar4pearlitic structure of iron carbide layers with G4ferrite$pure iron between. "f it is hypereutectoid steel $more than 0.:: wt% 9 then thestructure is full pearlite with small grains $larger than the pearlite lamellaof cementitescattered throughout. he relati(e amounts of constituents are found usingthe le(er rule. he following is a list of the types of heat treatments possible&

Spheroidi"ing& #pheroidite forms when carbon steel is heated to appro+imately :00 C9

for o(er 70 hours. #pheroidite can form at lower temperatures but the time neededdrastically increases, as this is a diffusion4controlled process. he result is a structure ofrods or spheres of cementite within primary structure $ferrite or pearlite, depending onwhich side of the eutectoid you are on. he purpose is to soften higher carbon steelsand allow more formability. his is the softest and most ductile form of steel. he imageto the right shows where spheroidi)ing usually occurs. /12

#ull annealing&9arbon steel is heated to appro+imately 0 C9 abo(e !c7 or !c1 for 1

hour* this ensures all the ferritetransforms into austenite$although cementitemight stille+ist if the carbon content is greater than the eutectoid. he steel must then be cooledslowly, in the realm of 20C9 $7-CF per hour. 8sually it is Hust furnace cooled, where thefurnace is turned off with the steel still inside. his results in a coarse pearlitic structure,which means the bands of pearliteare thick./17Fully annealed steel is soft andductile,with no internal stresses, which is often necessary for cost4effecti(e forming. Inlyspheroidi)ed steel is softer and more ductile./1
https://en.wikipedia.org/wiki/Phase_diagramhttps://en.wikipedia.org/wiki/Phase_diagramhttps://en.wikipedia.org/wiki/Phase_diagramhttps://en.wikipedia.org/wiki/Heat_treatmenthttps://en.wikipedia.org/wiki/Young's_modulushttps://en.wikipedia.org/wiki/Young's_modulushttps://en.wikipedia.org/wiki/Austenitehttps://en.wikipedia.org/wiki/Eutectoidhttps://en.wikipedia.org/wiki/Eutectoidhttps://en.wikipedia.org/wiki/Pearlitehttps://en.wikipedia.org/wiki/Pearlitehttps://en.wikipedia.org/wiki/Martensitehttps://en.wikipedia.org/wiki/Martensitehttps://en.wikipedia.org/wiki/Ferrite_(iron)https://en.wikipedia.org/wiki/Ferrite_(iron)https://en.wikipedia.org/wiki/Cementitehttps://en.wikipedia.org/wiki/Lever_rulehttps://en.wikipedia.org/wiki/Carbon_steel#cite_note-12https://en.wikipedia.org/wiki/Annealing_(metallurgy)https://en.wikipedia.org/wiki/Annealing_(metallurgy)https://en.wikipedia.org/wiki/Ferrite_(iron)https://en.wikipedia.org/wiki/Austenitehttps://en.wikipedia.org/wiki/Cementitehttps://en.wikipedia.org/wiki/Pearlitehttps://en.wikipedia.org/wiki/Carbon_steel#cite_note-Alvarenga-13https://en.wikipedia.org/wiki/Carbon_steel#cite_note-Alvarenga-13https://en.wikipedia.org/wiki/Ductilehttps://en.wikipedia.org/wiki/Carbon_steel#cite_note-14https://en.wikipedia.org/wiki/Phase_diagramhttps://en.wikipedia.org/wiki/Heat_treatmenthttps://en.wikipedia.org/wiki/Young's_modulushttps://en.wikipedia.org/wiki/Austenitehttps://en.wikipedia.org/wiki/Eutectoidhttps://en.wikipedia.org/wiki/Pearlitehttps://en.wikipedia.org/wiki/Martensitehttps://en.wikipedia.org/wiki/Ferrite_(iron)https://en.wikipedia.org/wiki/Cementitehttps://en.wikipedia.org/wiki/Lever_rulehttps://en.wikipedia.org/wiki/Carbon_steel#cite_note-12https://en.wikipedia.org/wiki/Annealing_(metallurgy)https://en.wikipedia.org/wiki/Ferrite_(iron)https://en.wikipedia.org/wiki/Austenitehttps://en.wikipedia.org/wiki/Cementitehttps://en.wikipedia.org/wiki/Pearlitehttps://en.wikipedia.org/wiki/Carbon_steel#cite_note-Alvarenga-13https://en.wikipedia.org/wiki/Ductilehttps://en.wikipedia.org/wiki/Carbon_steel#cite_note-14


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$rocess annealing& ! process used to relie(e stress in a cold4worked carbon steel with

less than 0.7 wt% 9. he steel is usually heated up to 0-0 C9 for 1 hour, butsometimes temperatures as high as :00 C9. he image rightward shows the area whereprocess annealing occurs.

%sothermal annealing& "t is a process in which hypoeutectoid steel is heated abo(e the

upper critical temperature and this temperature is maintained for a time and then thetemperature is brought down below lower critical temperature and is again maintained.hen finally it is cooled at room temperature. his method rids any temperaturegradient.

&ormali"ing& 9arbon steel is heated to appro+imately C9 abo(e !c7 or !cm for 1

hour* this ensures the steel completely transforms to austenite. he steel is then air4cooled, which is a cooling rate of appro+imately 7; C9 $100 CF per minute. his resultsin a fine pearlitic structure, and a more4uniform structure. ormali)ed steel has a higherstrength than annealed steel* it has a relati(ely high strength and hardness. /1

'uenching& 9arbon steel with at least 0. wt% 9 is heated to normali)ing temperatures

and then rapidly cooled $'uenched in water, brine, or oil to the critical temperature. hecritical temperature is dependent on the carbon content, but as a general rule is loweras the carbon content increases. his results in a martensitic structure* a form of steelthat possesses a super4saturated carbon content in a deformed body4centered cubic$


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resistance, and less distortion. he disad(antage of austempering is it can only be usedon a few steels, and it re'uires a special salt bath. /1D

Case hardening/editMain article: Case hardening

9ase hardening processes harden only the e+terior of the steel part, creating a hard, wearresistant skin $the case but preser(ing a tough and ductile interior. 9arbon steels are not(ery hardenable* therefore thick pieces cannot be through4hardened. !lloy steels ha(e abetter hardenability, so they can through4harden and do not re'uire case hardening. hisproperty of carbon steel can be beneficial, because it gi(es the surface good wearcharacteristics but lea(es the core tough.

Link: wikipedia

6ow carbon steelis a type of metal that has an alloying element made up of a relati(ely low amount of carbon. ypically, it has a

carbon content that ranges between 0.0% and 0.70% and amanganesecontent that falls between 0.0 and 1.%. 6ow carbon

steel is one of the most common types of steel used for general purposes, in part because it is often less e+pensi(e than other types

of steel. While the steel contains properties that work well in manufacturing a (ariety of goods, it is most fre'uently made into flat4

rolled sheets or strips of steel.

"tems made from low carbon steel compete with products that can be manufactured using stainless steel and aluminum alloy

metals. 6ow carbon steel can be used to manufacture a wide range of manufactured goods 4 from home appliances and ship sides

to low carbon steel wire andtinplates. #ince it has a low amount of carbon in it, the steel is typically more malleable than other

kinds of steel. !s a result, it can be rolled thin into products like car body panels.

!d

he carbon content for panels that are made of low carbon steel alloy is usually 'uite low, generally less than 0.10%. he carbon

content for products like rolled steel structural plates, forgings, stampings, or sections is a bit higher, usually up to 0.70%. Aipes are

a common product made from the higher carbon category. @enerally, a low carbon steel pipeis used for transmitting substances

such as gas and oil.

he steelmaking process as well as the deo+idation method can influence the properties of low carbon steel. "n general, these

properties are comparable to those of iron. 6ower carbon steels usually ha(e softer and weaker properties than steels containing

higher carbon content. his can make them easier to weld.

Ither types of carbon steel include medium, high, and ultrahigh carbon steels. 3edium carbon steelcustomarily has a carboncontent ranging between 0.70 and 0.-0% and a manganese content falling between 0.-0 and 1.-%. "t is fre'uently used for

making products like a+les, gears, shafts, and rail systems. Iften used for making ultra4strength wires or spring materials, high

carbon steel usually has a carbon content ranging between 0.-0 and 1.0% and a manganese content ranging between 0.70 to

0.D0%. 8ltrahigh carbon steel, which can be used for manufacturing items like kni(es, is thermomechanically processed and

ordinarily has a carbon content of 1.2 to 2.0%.

Link: http://www.wisegeek.com/what-is-low-carbon-steel.htm

5igh 9arbon #teelsAbstra)ti*

@enerally, the high carbon steels contain from 0.-0 to 1.00% 9 with manganese contents ranging from 0.70 to

0.D0%.

he pearlite has a (ery fine structure, which makes the steel (ery hard. 8nfortunately this also makes the steel 'uite

brittle and much less ductile than mild steel.

3edium and high carbon steels are widely used in many common applications. "ncreasing carbon as the primary alloy for the higher

strength and hardness of steels is usually the most economical approach to impro(ed performance. 5owe(er, some of the effects of

ele(ated carbon le(els include reduced weldability, ductility and impact toughness. When these reduced properties can be tolerated,
https://en.wikipedia.org/wiki/Carbon_steel#cite_note-19https://en.wikipedia.org/w/index.php?title=Carbon_steel&action=edit&section=10https://en.wikipedia.org/wiki/Case_hardeninghttps://en.wikipedia.org/wiki/Hardenabilityhttp://www.wisegeek.com/what-is-carbon-steel.htmhttp://www.wisegeek.com/what-is-carbon-steel.htmhttp://www.wisegeek.com/what-is-manganese.htmhttp://www.wisegeek.com/what-is-manganese.htmhttp://www.wisegeek.com/what-is-tin.htmhttp://www.wisegeek.com/what-is-tin.htmhttp://www.wisegeek.com/what-is-steel-pipe.htmhttp://www.wisegeek.com/what-is-medium-carbon-steel.htmhttp://www.wisegeek.com/what-is-medium-carbon-steel.htmhttp://www.wisegeek.com/what-is-low-carbon-steel.htmhttps://en.wikipedia.org/wiki/Carbon_steel#cite_note-19https://en.wikipedia.org/w/index.php?title=Carbon_steel&action=edit&section=10https://en.wikipedia.org/wiki/Case_hardeninghttps://en.wikipedia.org/wiki/Hardenabilityhttp://www.wisegeek.com/what-is-carbon-steel.htmhttp://www.wisegeek.com/what-is-manganese.htmhttp://www.wisegeek.com/what-is-tin.htmhttp://www.wisegeek.com/what-is-steel-pipe.htmhttp://www.wisegeek.com/what-is-medium-carbon-steel.htmhttp://www.wisegeek.com/what-is-low-carbon-steel.htm


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the increased strength and hardness of the higher carbon materials can be used to a significant ad(antage. 9ommon applications of

higher carbon steels include forging grades, rail steels, spring steels $both flat rolled and round, pre4stressed concrete, wire rope,

tire reinforcement, wear resistant steels $plates and forgings, and high strength bars.

o increase the performance of steels in these applications, it is common to ma+imi)e strength and hardness by raising the carbon

le(el to the highest practical le(el. he limiting factor to carbon additions will (ary depending on the type of applications. For forging

steels and bar products, it may be toughness or weldability. For high strength wire, the limiting factor for carbon addition is generally

the eutectoid carbon le(el, abo(e which the presence of grain boundary carbides will dramatically reduce drawability.

@enerally, the high carbon steels contain from 0.-0 to 1.00% 9 with manganese contents ranging from 0.70 to 0.D0%. 5igh carbon

steels are used for spring materials and high4strength wires. 8ltrahigh carbon steels are e+perimental alloys containing

appro+imately 1.2 to 2.0% 9. hese steels are thermomechanically processed to produce microstructures that consist of ultrafine,

e'uia+ed grains of ferrite and a uniform distribution of fine, spherical, discontinuous proeutectoid carbide particles. #uch

microstructures in these steels ha(e led to superplastic beha(ior.

#igure +*5istorical Kescription of the Fe49 phase diagram


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#igure ,*3icrostructure of high carbon steel

Figure 2 shows the microstructure of high carbon steel with about 0.;% 9 by weight, alloyed with iron. he steel has one maHor

constituent, which is pearlite. "t is made up from a fine mi+ture of ferrite and iron carbide, which can be seen as a wormy te+ture.

he pearlite has a (ery fine structure, which makes the steel (ery hard. 8nfortunately this also makes the steel 'uite brittle and

much less ductile than mild steel. he high carbon steel has good wear resistance, and until recently was used for railways. "t is also

used for cutting tools, such as chisels and high strength wires. hese applications re'uire a much finer microstructure, which

impro(es the toughness.

he common standards which define high carbon spring steel wire are&

!#3 !422: 9lass "=""

!#3 !41: 9lass "=""!#3 !40: ype !=


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#trictly speaking, e(ery steel is an alloy, but not all steels are called alloy steels. he simpleststeels areiron$Fe alloyed withcarbon$9 $about 0.1% to 1%, depending on type. 5owe(er, theterm alloy steel is the standard term referring to steels with otheralloying elements addeddeliberately in addition tothe carbon.9ommon alloyants include manganese$the most commonone, nickel,chromium,molybdenum, (anadium, silicon, and boron. 6ess common alloyantsinclude aluminum,cobalt,copper, cerium, niobium,titanium,tungsten,tin,)inc,lead,and)irconium.

he following is a range of impro(ed properties in alloy steels $as compared to carbonsteels& strength,hardness,toughness, wear resistance,corrosion resistance, hardenability, and hothardness.o achie(e some of these impro(ed properties the metal may re'uire heat treating.

#ome of these find uses in e+otic and highly4demanding applications, such as in the turbine bladesofHet engines, inspacecraft, and in nuclear reactors.


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most familiar stainless steel is probably #!L 70 stainless steel,also called 1;=; or !2 stainlesssteel. ype 70 surgical stainless steel is an austenitic steel containing 1;420% chromium and ;410% nickel.

!lloy 20 $9arpenter 20 is an austenitic stainless steel possessing e+cellent resistance to hot sulfuricacid and many other aggressi(e en(ironments which would readily attack type 71- stainless.hisalloy e+hibits superior resistance to stress4corrosion cracking in boiling 2040% sulfuric acid. !lloy 20has e+cellent mechanical properties and the presence of columbium in the alloy minimi)es theprecipitation of carbides during welding./1

!ustenitic stainless steel can be tested by nondestructi(e testingusing the dye penetrantinspectionmethod but not the magnetic particle inspectionmethod. Lddy4current testingmay also beused. "t is the primary stainless steel used in a(iation construction. 9hemical and steel industry4applicable grades are#!L steel grades70;, 70;6, 71-, 71-6, 71-6 $nitrogen bearing, 712, 70D6,and 7106. 6 denotes a carbonpercentage less than 0.07%, mostly used for corrosion heatresistance and reducing sensiti(ity to chromium carbide formation. !nother grade, 712, is used fordissimilar steel welding, also known as uni(ersal alloy steel as unknown composition steels can bewelded. For high temperature applications at greater than -00C9, grades 70D and 710 are preferred.@rade 71- is alloyed with molybdenum $N27% for high4temperature strength, pitting and cre(icecorrosion resistance.

Martensitic stainless steelFrom Wikipedia, the free encyclopedia

Martensitic stainless steelis a specific type of stainless steelalloy.

#tainless steels may be classified by their crystalline structureinto three maintypes&Austenitic, Ferriticand Martensitic. 3artensitic stainless steels can be high /1or are low carbonsteels built around the ype 10 composition of iron, 12% chromium, and 0.12% carbon. hey areusually tempered and hardened. empered martensite gi(es steel good hardness and hightoughness* used largely for medical tools $scalpels, ra)ors and internal clamps. /28ntempered

martensite is low in toughness and therefore brittle.he characteristic body centered tetragonal martensite microstructurewas first obser(ed by @ermanmicroscopist!dolf 3artensaround 1;D0. "n 1D12, Llwood 5aynesapplied for a 8.#. patent ona martensiticstainless steel alloy. his patent was not granted until 1D1D. /7

3artensitic stainless steel can be tested by ondestructi(e testingusing the 3agnetic particleinspectionmethod, unlikeaustenitic stainless steel.

!lso in 1D12,5arry


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This article needs additional citations forverification$ Please helpimpro%e this articlebyadding citations to reliable

sources$&nsourced material may be challenged and remo%ed$ (February 2010)

$recipitation hardening, also called age hardening, is aheat treatmenttechni'ue used toincrease the yield strength of malleablematerials, including most structural alloysofaluminium,magnesium,nickel,titanium, and some stainless steels. "nsuperalloys, it is known to

cause yield strength anomalypro(iding e+cellent high4temperature strength.

Arecipitation hardening relies on changes in solid solubilitywith temperatureto produce fine particlesof an impurity phase, which impede the mo(ement of dislocations, or defects in a crystal?s lattice.#ince dislocations are often the dominant carriers ofplasticity, this ser(es to harden the material.he impurities play the same role as the particle substances in particle4reinforcedcompositematerials. Must as the formation of ice in air can produce clouds, snow, or hail, dependingupon the thermal history of a gi(en portion of the atmosphere,precipitationin solids can producemany different si)es of particles, which ha(e radically different properties. 8nlike ordinary tempering,alloys must be kept at ele(ated temperature for hours to allow precipitation to take place. his timedelay is called aging. #olution treatment and aging is sometimes abbre(iated #! inmetals specsand certs.

ote that two different heat treatments in(ol(ing precipitates can alter the strength of a material&solution heat treating and precipitation heat treating. #olid solution strengtheningin(ol(es formationof a single4phase solid solution (ia 'uenching. Arecipitation heat treating in(ol(es the addition ofimpurity particles to increase a material?s strength. /1Arecipitation hardening (ia precipitation heattreatment is the main topic of discussion in this article.

Arecipitation 5ardening of !luminum !lloysAbstra)ti*

Arecipitation hardening, or age hardening, pro(ides one of the most widely used mechanisms for the strengthening of

metal alloys. he strongest aluminum alloys $2+++, -+++ and :+++ are produced by age hardening."n order for an alloy system to be able to be precipitation4strengthened, there must be a terminal solid solution that

has a decreasing solid solubility as the temperature decreases. he precipitation4hardening process in(ol(es three

basic steps& solution treatment, 'uenching and aging.

Arecipitation hardening, or age hardening, pro(ides one of the most widely used mechanisms for the strengthening of metal alloys.

he fundamental understanding and basis for this techni'ue was established in early work at the 8. #.


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#igure +*he aluminum rich end of the !l49u phase diagram showing the three steps in the age4hardening heat treatment and the

microstructures that are produced.

"n an attempt to understand the dramatic strengthening of this alloy, Aaul K. 3erica and his coworkers studied both the effect of

(arious heat treatments on the hardness of the alloy and the influence of chemical composition on the hardness. !mong the most

significant of their findings was the obser(ation that the solubility of 9u!l2 in aluminum increased with increasing temperature.

!lthough the specific phases responsible for the hardening turned out to be too small to be obser(ed directly, optical e+amination of

the microstructures pro(ided an identification of se(eral of the other phases that were present. he authors proceeded to de(elop an

insightful e+planation for the hardening beha(ior of Kuralumin which rapidly became the model on which innumerable modern high4

strength alloys ha(e been de(eloped.

hey summari)ed the four principal features of the original Kuralumin theory&

age4hardening is possible because of the solubility4temperature relation of the hardening constituent in aluminum,

the hardening constituent is 9u!l2,

hardening is caused by precipitation of the constituent in some form other than that of atomic dispersion, and probably in fine molecular,

colloidal or crystalline form, and

the hardening effect of 9u!l2in aluminum was deemed to be related to its particle si)e.

he precipitation4hardening process in(ol(es three basic steps&

+ Solution Treatment, or #olutioni)ing, is the first step in the precipitation4hardening process where the alloy is heated abo(e the

sol(us temperature and soaked there until a homogeneous solid solution $G is produced. he Q precipitates are dissol(ed in this

step and any segregation present in the original alloy is reduced.

, 'uenchingis the second step where the solid G is rapidly cooled forming a supersaturated solid solution of G##which contains

e+cess copper and is not an e'uilibrium structure. he atoms do not ha(e time to diffuse to potential nucleation sites and thus Q

precipitates do not form.

3 Agingis the third step where the supersaturated G, G##, is heated below the sol(us temperature to produce a finely dispersed

precipitate. !toms diffuse only short distances at this aging temperature.


13/28

! general model for decomposition is gi(en, followed by details of the precipitation se'uences in specific alloy systems& !l49u, !l4

9u43g, !l43g4#i and !l4Rn43g. he !l49u system is used as the main e+ample of decomposition, i.e.

a0 $####S @A )ones S Q?? S SQ? S Q or, more fully&

a0 $####S G1P @A )ones S G2P Q?? S G7P Q? S GP Q

Age Hardening / Strengtheninghe 7 main mechanisms are&

9oherency strain hardening*

9hemical hardening*

Kispersion hardening

9oherency strain hardening results from the interaction between dislocations and the strain fields surrounding @A )ones and=or

coherent precipitates. 9hemical hardening results from the increase in applied stress re'uired for a dislocation to cut through a

coherent $or semi4coherent precipitate. his in turn depends on a number of factors, including&

the e+tra inter1acial area4 and hence energy 4 between precipitate and matri+*

the possible creation of an anti-phase boundar$!A


14/28

Graphite

Martensite

Microstructures

Spheroidite

Pearlite

Bainite

Ledeburite

Tempered martensite

Widmanstatten structures

Classes

Crucible steel

Carbon steel

Spring steel

Alloy steel

Maraging steel

Stainless steel

Weathering steel

Tool steel

Other iron-based materials

Cast iron

Gray iron

White iron

Ductile iron

Malleable iron

Wrought iron

T

!

Tool steelrefers to a (ariety of carbonandalloy steelsthat are particularly well4suited to be madeinto tools. heir suitability comes from their distincti(e hardness, resistance to abrasionand

deformation and their ability to hold a cutting edge at ele(ated temperatures. !s a result tool steelsare suited for their use in the shaping of other materials.

With a carbon content between 0.% and 1.%, tool steels are manufactured under carefullycontrolled conditions to produce the re'uired 'uality. he presence of carbides in their matri+ playsthe dominant role in the 'ualities of tool steel. he four maHor alloying elements in tool steel that formcarbides are& tungsten, chromium, (anadium and molybdenum. he rate of dissolution of thedifferent carbides into the austeniteform of the iron determines the high temperature performance ofsteel. Aroperheat treatmentof these steels is important for ade'uate performance.
https://en.wikipedia.org/wiki/Graphitehttps://en.wikipedia.org/wiki/Martensitehttps://en.wikipedia.org/wiki/Microstructurehttps://en.wikipedia.org/wiki/Spheroiditehttps://en.wikipedia.org/wiki/Pearlitehttps://en.wikipedia.org/wiki/Bainitehttps://en.wikipedia.org/wiki/Ledeburitehttps://en.wikipedia.org/wiki/Tempering_(metallurgy)#Physical_processeshttps://en.wikipedia.org/wiki/Widmanstatten_patternhttps://en.wikipedia.org/wiki/Crucible_steelhttps://en.wikipedia.org/wiki/Carbon_steelhttps://en.wikipedia.org/wiki/Spring_steelhttps://en.wikipedia.org/wiki/Alloy_steelhttps://en.wikipedia.org/wiki/Maraging_steelhttps://en.wikipedia.org/wiki/Stainless_steelhttps://en.wikipedia.org/wiki/Weathering_steelhttps://en.wikipedia.org/wiki/Cast_ironhttps://en.wikipedia.org/wiki/Gray_ironhttps://en.wikipedia.org/wiki/White_ironhttps://en.wikipedia.org/wiki/Ductile_ironhttps://en.wikipedia.org/wiki/Malleable_ironhttps://en.wikipedia.org/wiki/Wrought_ironhttps://en.wikipedia.org/wiki/Template:Steelshttps://en.wikipedia.org/wiki/Template:Steelshttps://en.wikipedia.org/wiki/Template_talk:Steelshttps://en.wikipedia.org/wiki/Template_talk:Steelshttps://en.wikipedia.org/w/index.php?title=Template:Steels&action=edithttps://en.wikipedia.org/w/index.php?title=Template:Steels&action=edithttps://en.wikipedia.org/wiki/Carbon_steelhttps://en.wikipedia.org/wiki/Alloy_steelhttps://en.wikipedia.org/wiki/Alloy_steelhttps://en.wikipedia.org/wiki/Alloy_steelhttps://en.wikipedia.org/wiki/Toolhttps://en.wikipedia.org/wiki/Hardnesshttps://en.wikipedia.org/wiki/Wear#Abrasive_wearhttps://en.wikipedia.org/wiki/Austenitehttps://en.wikipedia.org/wiki/Austenitehttps://en.wikipedia.org/wiki/Heat_treatmenthttps://en.wikipedia.org/wiki/Heat_treatmenthttps://en.wikipedia.org/wiki/Heat_treatmenthttps://en.wikipedia.org/wiki/Graphitehttps://en.wikipedia.org/wiki/Martensitehttps://en.wikipedia.org/wiki/Microstructurehttps://en.wikipedia.org/wiki/Spheroiditehttps://en.wikipedia.org/wiki/Pearlitehttps://en.wikipedia.org/wiki/Bainitehttps://en.wikipedia.org/wiki/Ledeburitehttps://en.wikipedia.org/wiki/Tempering_(metallurgy)#Physical_processeshttps://en.wikipedia.org/wiki/Widmanstatten_patternhttps://en.wikipedia.org/wiki/Crucible_steelhttps://en.wikipedia.org/wiki/Carbon_steelhttps://en.wikipedia.org/wiki/Spring_steelhttps://en.wikipedia.org/wiki/Alloy_steelhttps://en.wikipedia.org/wiki/Maraging_steelhttps://en.wikipedia.org/wiki/Stainless_steelhttps://en.wikipedia.org/wiki/Weathering_steelhttps://en.wikipedia.org/wiki/Cast_ironhttps://en.wikipedia.org/wiki/Gray_ironhttps://en.wikipedia.org/wiki/White_ironhttps://en.wikipedia.org/wiki/Ductile_ironhttps://en.wikipedia.org/wiki/Malleable_ironhttps://en.wikipedia.org/wiki/Wrought_ironhttps://en.wikipedia.org/wiki/Template:Steelshttps://en.wikipedia.org/wiki/Template_talk:Steelshttps://en.wikipedia.org/w/index.php?title=Template:Steels&action=edithttps://en.wikipedia.org/wiki/Carbon_steelhttps://en.wikipedia.org/wiki/Alloy_steelhttps://en.wikipedia.org/wiki/Toolhttps://en.wikipedia.org/wiki/Hardnesshttps://en.wikipedia.org/wiki/Wear#Abrasive_wearhttps://en.wikipedia.org/wiki/Austenitehttps://en.wikipedia.org/wiki/Heat_treatment


15/28

/1he manganesecontent is often kept low to minimi)e the possibility of cracking duringwater'uenching.

here are si+ groups of tool steels& water4hardening, cold4work, shock4resisting, high4speed, hot4work, and special purpose. he choice of group to select depends on, cost, working temperature,re'uired surface hardness, strength, shock resistance, and toughness re'uirements. /2he morese(ere the ser(ice condition $higher temperature, abrasi(eness, corrosi(eness, loading, the higherthe alloy content and conse'uent amount of carbides re'uired for the tool steel.

ool steels are used for cutting, pressing, e+truding, and coining of metals and other materials. heiruse for applications likeinHection moldingdue to their the resistance to abrasion is an importantcriterion for a mold that will be used to produce hundreds of thousands of parts is essential.

he!"#"4#!Lgrades of tool steel is the most common scale used to identify (arious grades of toolsteel. "ndi(idual alloys within a grade are gi(en a number* for e+ample& !2, I1, etc.

Contents

/hide

1 Water4hardening group

2 9old4work group

o 2.1 Iil4hardening

o 2.2 !ir4hardening

o 2.7 5igh carbon4chromium, K4type

o 2. 1.2:-: type

7 #hock4resisting group

5igh speed group

5ot4working group

- #pecial purpose group

: 9omparison

; #ee also

D eferences

10


16/28

'uenching, re'uiring the use of water. hese steels can attain high hardness $abo(e 59 -- andare rather brittle compared to other tool steels. W4steels are still sold, especially for springs, but aremuch less widely used than they were in the 1Dth and early 20th centuries. his is partly because W4steels warp and crack much more during 'uench than oil4'uenched or air hardening steels.

he toughness of W4group tool steels are increased by alloying with manganese, silicon andmolybdenum. 8p to 0.20% of (anadium is used to retain fine grain si)es during heat treating.

ypical applications for (arious carbon compositions are for W4steels&

0.-00.:% carbon& machine parts, chisels, setscrews* properties include medium hardness

with good toughness and shock resistance.

0.:-0.D0% carbon& forging dies, hammers, and sledges.

0.D11.10% carbon& general purpose tooling applications that re'uire a good balance of

wear resistance and toughness, such as rasps, drills, cutters, and shear blades.

1.111.70% carbon& files, small drills, lathe tools, ra)or blades, and other light4duty

applications where more wear resistance is re'uired without great toughness. #teel of about0.;% 9 gets as hard as steel with more carbon, but the free iron carbide particles in 1% or1.2% carbon steel make it hold an edge better. 5owe(er, the fine edge probably rusts off fasterthan it wears off, if it is used to cut acidic or salty materials.

Cold-work group/edit

he cold4work tool steels are a group of steels used to cut or form materials that are at lowtemperatures. he group consists of three groups of steels& oil4hardening, air4hardening, and highcarbon4chromium. his group possesses high hardenability and wear resistance, and a(eragetoughness and heat softening resistance. hey are used in production of larger parts or parts thatre'uire minimal distortion during hardening. he use of oil 'uenching and air4hardening helps reduce

distortion, a(oiding the higher stresses caused by the 'uicker water 'uenching. 3ore alloyingelements are used in these steels, as compared to the water4hardening class. hese alloys increasethe steels? hardenability, and thus re'uire a less se(ere 'uenching process and as a result are lesslikely to crack. hey ha(e high surface hardness and are often used to make knife blades. hemachinability of the oil hardening grades is high and low for the high carbon4chromium types.

2il-hardening/edit

!rad

eComposition "otes

'()$*)+C,($)-($.+Mn,)$/)+Cr,

)$/)+W

0t is a %ery good cold 1or2 steel and also ma2es %ery good 2ni%es and 3or2s$ 0t can be

hardened to about /456( 78C$

Air-hardening/edit

he first air4hardening grade tool steel was mushet steel, which was known as air-hardening steelatthe time.

3odern air4hardening steels are characteri)ed by low distortion during heat treatment because oftheir high4chromium content. hey also harden in air due to their alloy than oil4hardening grades.
https://en.wikipedia.org/w/index.php?title=Tool_steel&action=edit&section=2https://en.wikipedia.org/w/index.php?title=Tool_steel&action=edit&section=3https://en.wikipedia.org/w/index.php?title=Tool_steel&action=edit&section=3https://en.wikipedia.org/wiki/Carbonhttps://en.wikipedia.org/wiki/Carbonhttps://en.wikipedia.org/wiki/Carbonhttps://en.wikipedia.org/wiki/Manganesehttps://en.wikipedia.org/wiki/Manganesehttps://en.wikipedia.org/wiki/Manganesehttps://en.wikipedia.org/wiki/Chromiumhttps://en.wikipedia.org/wiki/Chromiumhttps://en.wikipedia.org/wiki/Tungstenhttps://en.wikipedia.org/wiki/Tungstenhttps://en.wikipedia.org/w/index.php?title=Tool_steel&action=edit&section=4https://en.wikipedia.org/wiki/Mushet_steelhttps://en.wikipedia.org/w/index.php?title=Tool_steel&action=edit&section=2https://en.wikipedia.org/w/index.php?title=Tool_steel&action=edit&section=3https://en.wikipedia.org/wiki/Carbonhttps://en.wikipedia.org/wiki/Manganesehttps://en.wikipedia.org/wiki/Chromiumhttps://en.wikipedia.org/wiki/Tungstenhttps://en.wikipedia.org/w/index.php?title=Tool_steel&action=edit&section=4https://en.wikipedia.org/wiki/Mushet_steel


17/28

heir machinability is good and they ha(e a balance of wear resistance and toughness $i.e. betweenthe K4 and shock4resistant grades. /7

!rad

eComposition "otes

A9".#($)+C,($)+Mn,/$)+Cr,

)$:+;i,($)+ Mo, )$(/-)$/)+

A common general purpose tool steel< it is the most commonly used %ariety o3 air5hardening

steel$ 0t is commonly used 3or blan2ing and 3orming punches, trimming dies, thread rolling

dies, and in=ection molding dies$":#

A:"/#($9/+ C, )$/+ Mn, /$)+ Cr, )$:+

;i, )$*-($.+ Mo, )$>-($.+

A."6#($)+ C, 9$)+ Mn, ($)+ Cr, )$:+

;i, )$*-($.+ Mo

A6"4#)$4+ C, ($>-9$/+ Mn, )$*-($9+

Cr, )$:+ ;i, )$*-($.+ Mo

This type o3 tool steel air5hardens at a relati%ely lo1 temperature ?appro@imately the sametemperature as oil5hardening types and is dimensionally stable$ There3ore it is commonly

used 3or dies, 3orming tools, and gauges that do not reuire e@treme 1ear resistance but do

need high stability$":#

A4">#9$))-9$>/+ C, )$>+ Mn, /$))-

/$4/+ Cr, )$:+ ;i, )$*-($.+ Mo,:$*-/$(/+ , )$/-($/ W

A>

"*#

)$/-)$6+ C, )$/+ Mn, .$4/-/$/)+

Cr, )$:+ ;i, ($(/-($6/+ Mo, ($)-($/ W

A*"()#)$/+ C, )$/+ Mn, )$*/-($(/+Si,

.$4/-/$))+ Cr, ($9/-($4/+ ;i,

($:-($>+ Mo, )$>-($.+

A()"((#($9/-($/)+ C, ($6-9$(+ Mn, ($)-($/+ Si, ($//-9$)/+ ;i, ($9/-

($4/+ Mo

This grade contains a uni3orm distribution o3graphiteparticles to increase machinability andpro%ide sel35lubricating properties$ 0t is commonly used 3or gauges, arbors, shears, and

punches$"(9#

High carbon-chromium -tpe/edithe K4type, of the cold4work class of tool steels, contain between 10% and 17% chromium. hesesteels retain their hardness up to a temperature of 2 C9 $:D: CF. 9ommon applications for thesetool steels include forging dies, die4casting die blocks, and drawing dies. Kue to their high chromiumcontent, certain K4type tool steels are often consideredstainlessor semi4stainless, howe(er theircorrosion resistance is (ery limited due to the precipitation of the maHority of their chromium andcarbon constituents as carbides.
https://en.wikipedia.org/wiki/Tool_steel#cite_note-oberg466-3https://en.wikipedia.org/wiki/Tool_steel#cite_note-4https://en.wikipedia.org/wiki/Carbonhttps://en.wikipedia.org/wiki/Carbonhttps://en.wikipedia.org/wiki/Carbonhttps://en.wikipedia.org/wiki/Manganesehttps://en.wikipedia.org/wiki/Manganesehttps://en.wikipedia.org/wiki/Manganesehttps://en.wikipedia.org/wiki/Chromiumhttps://en.wikipedia.org/wiki/Chromiumhttps://en.wikipedia.org/wiki/Nickelhttps://en.wikipedia.org/wiki/Nickelhttps://en.wikipedia.org/wiki/Nickelhttps://en.wikipedia.org/wiki/Molybdenumhttps://en.wikipedia.org/wiki/Vanadiumhttps://en.wikipedia.org/wiki/Vanadiumhttps://en.wikipedia.org/wiki/Tool_steel#cite_note-oberg466-3https://en.wikipedia.org/wiki/Tool_steel#cite_note-oberg466-3https://en.wikipedia.org/wiki/Tool_steel#cite_note-5https://en.wikipedia.org/wiki/Tool_steel#cite_note-6https://en.wikipedia.org/wiki/Tool_steel#cite_note-7https://en.wikipedia.org/wiki/Tool_steel#cite_note-oberg466-3https://en.wikipedia.org/wiki/Tool_steel#cite_note-oberg466-3https://en.wikipedia.org/wiki/Tool_steel#cite_note-8https://en.wikipedia.org/wiki/Tungstenhttps://en.wikipedia.org/wiki/Tool_steel#cite_note-9https://en.wikipedia.org/wiki/Tool_steel#cite_note-10https://en.wikipedia.org/wiki/Siliconhttps://en.wikipedia.org/wiki/Siliconhttps://en.wikipedia.org/wiki/Siliconhttps://en.wikipedia.org/wiki/Tool_steel#cite_note-11https://en.wikipedia.org/wiki/Graphitehttps://en.wikipedia.org/wiki/Graphitehttps://en.wikipedia.org/wiki/Graphitehttps://en.wikipedia.org/wiki/Tool_steel#cite_note-12https://en.wikipedia.org/w/index.php?title=Tool_steel&action=edit&section=5https://en.wikipedia.org/wiki/Stainless_steelhttps://en.wikipedia.org/wiki/Stainless_steelhttps://en.wikipedia.org/wiki/Tool_steel#cite_note-oberg466-3https://en.wikipedia.org/wiki/Tool_steel#cite_note-4https://en.wikipedia.org/wiki/Carbonhttps://en.wikipedia.org/wiki/Manganesehttps://en.wikipedia.org/wiki/Chromiumhttps://en.wikipedia.org/wiki/Nickelhttps://en.wikipedia.org/wiki/Molybdenumhttps://en.wikipedia.org/wiki/Vanadiumhttps://en.wikipedia.org/wiki/Tool_steel#cite_note-oberg466-3https://en.wikipedia.org/wiki/Tool_steel#cite_note-5https://en.wikipedia.org/wiki/Tool_steel#cite_note-6https://en.wikipedia.org/wiki/Tool_steel#cite_note-7https://en.wikipedia.org/wiki/Tool_steel#cite_note-oberg466-3https://en.wikipedia.org/wiki/Tool_steel#cite_note-8https://en.wikipedia.org/wiki/Tungstenhttps://en.wikipedia.org/wiki/Tool_steel#cite_note-9https://en.wikipedia.org/wiki/Tool_steel#cite_note-10https://en.wikipedia.org/wiki/Siliconhttps://en.wikipedia.org/wiki/Tool_steel#cite_note-11https://en.wikipedia.org/wiki/Graphitehttps://en.wikipedia.org/wiki/Tool_steel#cite_note-12https://en.wikipedia.org/w/index.php?title=Tool_steel&action=edit&section=5https://en.wikipedia.org/wiki/Stainless_steel


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!rad

eComposition "otes

D9

($/+C,(($)-(:$)+ Cr< additionally

)$./+Mn,)$):)+P,)$):)+S,($)+, )$*+Mo,)$:)+Si

D9 is %ery 1ear resistant but not as tough as lo1er alloyed steels$ The mechanical

properties o3 D9 are %ery sensiti%e to heat treatment$ 0t is 1idely used 3or the productiono3 shear blades, planer blades and industrial cutting tools< sometimes used 3or 2ni3e

blades$

+,565 tpe/edit

"#I 1.2:-:, also known as K" O i9r3o , !"#" -F:, and


19/28

F4type tool steel is water hardened and substantially more wear resistant than W4type tool

steel.

Comparison/edit

#$S$-S#% tool steel grades"(.#

&efining property #$S$-S#% grade Significant characteristics

Water5hardening W

Cold51or2ing

' 'il5hardening

A Air5hardening< medium alloy

D 7igh carbon< high chromium

Shoc2 resisting S

7igh speed

T Tungsten base

M Molybdenum base

7ot51or2ing 7

7(-7(* chromium base

79)-7:* tungsten base

7.)-7/* molybdenum base

Plastic mold P

Special purpose

L Lo1 alloy

F Carbon tungsten

Introduction
https://en.wikipedia.org/w/index.php?title=Tool_steel&action=edit&section=11https://en.wikipedia.org/wiki/Tool_steel#cite_note-14https://en.wikipedia.org/wiki/Tool_steel#cite_note-14https://en.wikipedia.org/w/index.php?title=Tool_steel&action=edit&section=11https://en.wikipedia.org/wiki/Tool_steel#cite_note-14


20/28

AISI 1018 mild/low carbon steel has excellent weldability and produces a uniform and harder case and it is considered as

the best steel for carburized parts. AISI 1018 mild/low carbon steel offers a good balance of toughness strength and

ductility. !ro"ided with higher mechanical properties AISI 1018 hot rolled steel also includes impro"ed machining

characteristics and #rinell hardness.

Specific manufacturing controls are used for surface preparation chemical composition rolling and heating processes. All

these processes de"elop a supreme $uality product that are suited to fabrication processes such as welding forging

drilling machining cold drawing and heat treating.

Chemical Composition

Element Content

%arbon % 0.1& ' 0.(0 )

Iron *e +8.81 ' ++.(, ) -as remainder

anganese n 0.,0 ' 0.+0 )

!hosphorous ! 0.0&0 )

Sulfur S 0.00 )

Physical Properties

Physical Properties Metric Imperial

2ensity 3.83 g/cc 0.(8& lb/in4

Mechanical Properties

Mechanical Properties Metric Imperial

5ardness #rinell 1(, 1(,

5ardness 6noop -%on"erted from #rinell hardness 1& 1&

5ardness 7ocwell # -%on"erted from #rinell hardness 31 31

5ardness 9icers -%on"erted from #rinell hardness 141 141

:ensile Strength ;ltimate &&0 !a ,4800 psi

:ensile Strength !a (+300 si

#ul odulus -:ypical for steel 1&0 >!a (0400 si

!oissons 7atio -:ypical *or Steel 0.(+0 0.(+0

achinability -#ased on AISI 1(1( steel. as 100) machinability 30 ) 30 )

Shear odulus -:ypical for steel 80.0 >!a 11,00 si

Electrical Properties

Electrical Properties Metric English Comments

=lectrical resisti"ity ?0@% -4(@* 0.00001+ 'cm 0.00001+ 'cm annealed condition

?100 @%/ (1( @* 0.0000(1+ 'cm 0.0000(1+ 'cm annealed condition

? (00 @%/4+( @* 0.0000(+4 'cm 0.0000(+4 'cm annealed condition

Machining

:he machinability of AISI 1018 mild/low carbon steel is graded at 38) of #111(.

Weldability

AISI 1018 mild/low carbon steel can be instantly welded by all the con"entional welding processes. Belding is not

recommended for AISI 1018 mild/low carbon steel when it is carbonitrided and carburized.

Cow carbon welding electrodes are to be used in the welding procedure and post'heating and pre'heating are not

necessary. !re'heating can be performed for sections o"er 0 mm. !ost'weld stress relie"ing also has its own beneficial

aspects lie the pre'heating process.


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Heat Treatment

:he heat treatment for AISI 1018 mild/low carbon steel consists of the following processesD

Normalizing

AISI 1018 mild/low carbon steel should be heated at 8+0@% E +&0@% and then cooled in still air.

Forging

:his process re$uires heating between 110@% E 1(80@% and AISI 1018 mild/low carbon steel is held until the

temperature becomes constant.

+00@% is the minimum temperature re$uired for the forging process.

:he steel is then cooled in air after this process.

Tempering

AISI 1018 mild/low carbon steel is tempered at between 10@% E (00@% for impro"ement of case toughness. :his

process has little or no effect on hardness.

:he occurrence of grinding cracs is reduced when AISI 1018 mild/low carbon steel is tempered at the abo"e

mentioned temperature.

Annealing

:he AISI 1018 mild/low carbon steel is heated at 830@% E +10@% and allowed to cool in a furnace

tress !elie"ing

00@% E 300@% is re$uired to relie"e stress in AISI 1018 mild/low carbon steel that is later cooled down in still air.

Case Hardening

:his process re$uires heating to be carried out between 380@% E 8(0@%. AISI 1018 mild/low carbon steel is then

$uenched in water.

Core !e#ining

:his is an optional process that re$uires heating at 880@% E +(0@%.

AISI 1018 mild/low carbon steel after being heated is moistened in oil or water.

Carburizing

%arburizing taes place at 880@% E +(0@%.

Applications o# AII $%$& Mild'(o) Carbon teel

It is used in bending crimping and swaging processes.


22/28

%arburized parts that include worms gears pins dowels non'critical components of tool and die sets tool

holders pinions machine parts ratchets dowels and chain pins use AISI 1018 mild/low carbon steel.

It is widely used for fixtures mounting plates and spacers.

It is suitably used in applications that do not need high strength of alloy steels and high carbon.

It pro"ides high surface hardness and a soft core to parts that include worms dogs pins liners machinery parts

special bolts ratchets chain pins oil tool slips tie rods anchor pins studs etc.

It is used to impro"e drilling machining threading and punching processes.

It is used to pre"ent cracing in se"ere bends.

2ate AddedD Fun (8 (01( G ;pdatedD Ful 14 (014

6ow carbon steels offer many applications. ruck bed floors, automobile doors, domestic appliances, and spare tire tubs are Hust a

few of the things made with these types of steel.


23/28

Medium Carbon Steel

The uses for medium-carbon steel are dened b the re!uirement for a high tensile strength and

ductilit that" despite its brittleness when compared to other forms of steel" make it the preferred

choice. #etween $.% and $.& percent carbon is added during the manufacturing process to create a

medium or mid-range steel product. This specic range of carbon is combined with a process of

!uenching 'i.e." cooling the steel from the outer surface to the inner( and tempering to create a

structure that has a consistent tensile strength 'referred to as Martensite( throughout the bod.

Shafts and )earing

*+le shafts" crankshafts and gearing plates are all made from medium-carbon steel. The

ductilit of the steel allows it to be formed into thin shafts or toothed plates without losing an of its

tensile strength.

,ressured Structures

The ductilit of the medium-carbon steel allows it to be shaped into plates for boilers and other

tanks that hae highl pressuried contents. Medium-carbon steel cannot be used for pressuried tank

sstems that contain cold li!uids or gasses because the Martensite structure of the steel makes it

brittle and susceptible to cold cracking. Stainless steel or other high carbon steels are used for those

tpes of applications.

ailwa *pplications

ailwa wheels" rails and other steel parts associated with the suspension of rail cars are made

of medium-carbon steel. The high tensile strength is necessar to withstand the changing force of therail cars on the rails.

Structural Steel

Structural steel beams" 0oiner plates and other shapes associated with building re!uire a high

tensile strength to resist the tor!ue and pressure of buildings and bridges. Special care must be taken

to properl insulate the steel to preent it from being a1ected b e+tremes of heat and cold" which can

change the Martensite structure and lessen its structural integrit.

http://www.ehow.com/info2345$6782uses-mediumcarbon-steel.html

ead more : http://www.ehow.com/info2345$6782uses-mediumcarbon-steel.html
http://www.ehow.com/info_8520946_uses-mediumcarbon-steel.htmlhttp://www.ehow.com/info_8520946_uses-mediumcarbon-steel.htmlhttp://www.ehow.com/info_8520946_uses-mediumcarbon-steel.htmlhttp://www.ehow.com/info_8520946_uses-mediumcarbon-steel.html


24/28

he fracture characteristics of steels are strongly influenced by martensite substructure, retained austenite stability, and morphology.

!ttracti(e strength4toughness properties ha(e been attained with Fe49r4943n alloys. hese alloys, when tested under sliding wear

conditions, also e+hibit good wear resistance which compares fa(orably with that of commercial wear4resistant alloys. he most significant

finding is an apparently strong correlation between sliding wear resistance and retained austenite, which in turn appears to correlate with

9harpy impact properties. 6ittle correlation was obser(ed between hardness and wear resistance for the e+perimental steels.

http&==www.sciencedirect.com=science=article=pii=0071-;;2D017;:

9igh Carbon Steel ,roperties ;ses

Steel is one of the most important construction metals in the world.


25/28

9igh carbon steel remains popular for a wide ariet of uses. This tpe of steel is preferred in

the manufacturing of man tools such as drill bits" knies" masonr nails" saws" metal cutting tools"

and woodcutting tools.

http&==www.ehow.com=listZ:D-7;Zhigh4carbon4steel4properties4uses.html

#tainless steel is usually di(ided into types&

a. Ferritic hese steels are based on 9hromium with small amounts of 9arbon usually less than 0.10%.hese steels ha(e a similar microstructure to carbon and low alloy steels. hey are usually limited inuse to relati(ely thin sections due to lack of toughness in welds. 5owe(er, where welding is notre'uired they offer a wide range of applications. hey cannot be hardened by heat treatment. 5igh9hromium steels with additions of 3olybdenum can be used in 'uite aggressi(e conditions such as

sea water. Ferritic steels are also chosen for their resistance to stress corrosion cracking. hey are notas formable as austenitic stainless steels. hey are magnetic.b. !ustenitic4 hese steels are the most common. heir microstructure is deri(ed from the addition of

ickel, 3anganese and itrogen. "t is the same structure as occurs in ordinary steels at much highertemperatures. his structure gi(es these steels their characteristic combination of weldability andformability. 9orrosion resistance can be enhanced by adding 9hromium, 3olybdenum and itrogen.hey cannot be hardened by heat treatment but ha(e the useful property of being able to be workhardened to high strength le(els whilst retaining a useful le(el of ductility and toughness. #tandardaustenitic steels are (ulnerable to stress corrosion cracking. 5igher nickel austenitic steels ha(eincreased resistance to stress corrosion cracking. hey are nominally non4magnetic but usually e+hibitsome magnetic response depending on the composition and the work hardening of the steel.

c. 3artensitic4 hese steels are similar to ferritic steels in being based on 9hromium but ha(e higher9arbon le(els up as high as 1%. his allows them to be hardened and tempered much like carbon andlow4alloy steels. hey are used where high strength and moderate corrosion resistance is re'uired.

hey are more common in long products than in sheet and plate form. hey ha(e generally lowweldability and formability. hey are magnetic.d. Kuple+4 hese steels ha(e a microstructure which is appro+imately 0% ferritic and 0% austenitic.

his gi(es them a higher strength than either ferritic or austenitic steels. hey are resistant to stresscorrosion cracking. #o called [lean duple+\ steels are formulated to ha(e comparable corrosionresistance to standard austenitic steels but with enhanced strength and resistance to stress corrosioncracking. [#uperduple+\ steels ha(e enhanced strength and resistance to all forms of corrosioncompared to standard austenitic steels. hey are weldable but need care in selection of weldingconsumables and heat input. hey ha(e moderate formability. hey are magnetic but not so much asthe ferritic, martensitic and A5 grades due to the 0% austenitic phase.

e. Arecipitation hardening $A54 hese steels can de(elop (ery high strength by adding elements suchas 9opper, iobium and !luminium to the steel. With a suitable [aging\ heat treatment, (ery fineparticles form in the matri+ of the steel which imparts strength. hese steels can be machined to 'uiteintricate shapes re'uiring good tolerances before the final aging treatment as there is minimal

distortion from the final treatment. his is in contrast to con(entional hardening and tempering inmartensitic steels where distortion is more of a problem. 9orrosion resistance is comparable tostandard austenitic steels like 1.701 $70.

6"& http&==www.bssa.org.uk=fa'.phpXidY10
http://www.ehow.com/list_7596348_high-carbon-steel-properties-uses.htmlhttp://www.bssa.org.uk/topics.php?article=20http://www.bssa.org.uk/topics.php?article=22http://www.bssa.org.uk/topics.php?article=22http://www.bssa.org.uk/topics.php?article=253http://www.bssa.org.uk/topics.php?article=23http://www.bssa.org.uk/topics.php?article=24http://www.bssa.org.uk/topics.php?article=24http://www.bssa.org.uk/faq.php?id=10http://www.bssa.org.uk/faq.php?id=10http://www.ehow.com/list_7596348_high-carbon-steel-properties-uses.htmlhttp://www.bssa.org.uk/topics.php?article=20http://www.bssa.org.uk/topics.php?article=22http://www.bssa.org.uk/topics.php?article=253http://www.bssa.org.uk/topics.php?article=23http://www.bssa.org.uk/topics.php?article=24http://www.bssa.org.uk/faq.php?id=10


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#teel 9orrosion

he corrosion process that takes place on a piece of uncoated steel is (ery comple+. Factors such as (ariations in

the composition=structure of the steel, presence of impurities due to the higher instance of recycled steel, une(en

internal stress, and=or e+posure to non4uniform en(ironment all affect the corrosion process.

"t is (ery easy for microscopic areas of the e+posed steel to become relati(ely anodic or cathodic to one another. !

large number of such areas can de(elop in a small section of the e+posed steel. Further, it is highly possible se(eral

different types of gal(anic corrosion cells are present in the same small area of an acti(ely corroding piece of steel.

!s the corrosion process progresses, corrosion products tend to build up in certain areas of the metal. hese

corrosion products ha(e different elemental compositions than the original state. he new compositions e+posed on

the surface lead to changes in the anodic and cathodic areas. !s the change in anodic and cathodic areas occur,

pre(iously uncorroded areas of the metal can be attacked and corrode. his will accelerate the o(erall corrosion of

the steel surface.

"ronand steel, the most commonly usedmetals,corrode in many media including most outdoor atmospheres. 8sually they are selected not for their

corrosion resistance but for such properties as strength, ease of fabrication, and cost. hese differences show up in the rate of metal lost due to

rusting. !ll steels and low4alloy steels rust in moist atmospheres. "n some circumstances, the addition of 0.7% copperto carbon steel can reduce the

rate of rusting by one 'uarter or e(en by one half. ! modern and comprehensi(e document on the subHect is the second edition of theclassic9II#"I


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9austic cracking of steam4generating boilers was a serious problem in the late 1Dth century $the necessary strong caustic solution was produced by

e(aporation of the (ery dilute solution inside the boiler as it escaped through leaks in the ri(eted seams and boiler e+plosions led to significant loss of

life. 3ore recently gas t ransmission pipelines ha(e cracked in carbonate solutions produced under protecti(e coatings as a result of cathodic protection

systems. "n this case the crack runs along the length of the pipe, and may propagate for (ery long distances by fast fracture. "f the gas cloud that is

released ignites, the resultant fireball is de(astating.

6ink&http&==www.corrosion4doctors.org=3at#elect=corrsteel.htm

he corrosion products of steel are o+ide particles and ha(e a distincti(e brown=red $rust color. Must a small amount

of these particles can cause an uncoated steel surface to appear corroded. #teel corrodes naturally when e+posed

to the atmosphere, but the corrosion process accelerates when electrochemical corrosion cells are acti(e on the

surface.

6"& http&==www.gal(ani)eit.org=corrosion=corrosion4process=steel4corrosion

#teel is the World?s 3ost ecycled 3aterial

#teel is the most recycled material on the planet, more than all other materials combined. #teel retains an e+tremely high o(erall recycling

rate, which in 2012, stood at ;; percent.

he ama)ing metallurgical properties of steel allow it to be recycled continually with no degradation in performance, and from one product to

another.

he sources for steel scrap are plentiful, but are classified into three main categories& home scrap, prompt scrap and obsolete scrap.
http://www.corrosion-doctors.org/MatSelect/corrsteel.htmhttp://www.corrosion-doctors.org/MatSelect/corrsteel.htmhttp://www.corrosion-doctors.org/MatSelect/corrsteel.htm


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5ome scrap is the scrap that is produced from within the mill itself and is a(ailable within weeks. Arompt scrap is scrap that it is produced

from manufacturing products from steel, and is a(ailable within months. Ibsolete scrap is scrap produced from steel products at the end of

their li(es and it may be decades before this scrap is a(ailable $e+ample& he @olden @ate

types of steel

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