Lub luag haujlwm tseem ceeb ntawm nickel hauv stainless hlau yog tias nws hloov cov qauv siv lead ua ntawm cov hlau. Ib qho ntawm cov laj thawj tseem ceeb rau kev sib ntxiv ntawm npib tsib xee rau stainless hlau yog qhov tsim ntawm austenitic siv lead ua qauv, uas txhim kho stainless hlau cov khoom xws li ductility, weldability thiab toughness, yog li nickel hu ua austenite qub. Cov qauv siv lead ua ntawm cov pa roj carbon zoo tib yam hu ua ferrite, uas yog lub cev-centered cubic (BCC) qauv, thiab npib tsib xee ntxiv los txhawb cov qauv siv lead ua los ntawm lub cev-centered cubic (BCC) qauv mus rau lub ntsej muag-centered cubic (FCC). ) qauv, uas yog hu ua austenite. Txawm li cas los xij, npib tsib xee tsis yog ib qho khoom tsis tshua muaj nrog cov khoom zoo li no. Feem ntau austenite-forming ntsiab yog: npib tsib xee, carbon, nitrogen, manganese, thiab tooj liab. Cov txheeb ze tseem ceeb ntawm cov ntsiab lus no hauv kev tsim austenite muaj qhov cuam tshuam tseem ceeb rau kev kwv yees cov qauv siv lead ua ntawm stainless hlau. Tam sim no, ntau cov qauv tau tsim los qhia txog qhov tseem ceeb ntawm cov khoom austenite-forming. Qhov nto moo tshaj plaws yog cov qauv hauv qab no: Austenite-forming peev xwm =Ni%+30C%+30N%+0.5Mn%+0.25Cu%
Nws tuaj yeem pom los ntawm qhov sib npaug no tias carbon yog lub zog austenite-forming lub caij nrog 30 npaug ntawm lub peev xwm los tsim austenite dua npib tsib xee, tab sis nws tsis tuaj yeem ntxiv rau corrosion-resistant stainless hlau vim tias tom qab vuam nws tuaj yeem ua rau sensitized corrosion thiab tom qab intergranular corrosion. teeb meem. Nitrogen kuj yog 30 npaug ntau lub peev xwm ntawm kev tsim austenite tshaj npib tsib xee, tab sis nws yog ib qho roj thiab tsuas yog txwv cov nitrogen tuaj yeem ntxiv rau cov hlau tsis muaj teeb meem porosity. Qhov sib ntxiv ntawm manganese thiab tooj liab tuaj yeem ua rau muaj teeb meem nrog txo lub neej ntawm refractory thiab vuam hauv cov txheej txheem steelmaking.
Raws li koj tuaj yeem pom los ntawm kev sib npaug npib tsib xee, qhov sib ntxiv ntawm manganese tsis zoo heev hauv kev tsim austenite, tab sis ntxiv ntawm manganese tso cai rau ntau nitrogen, uas yog ib qho muaj zog austenite qub, kom yaj rau hauv cov hlau tsis muaj steel. Nyob rau hauv 200 series stainless hlau, nws yog txaus manganese thiab nitrogen los hloov nickel los ua ib tug 100% austenitic qauv. Qhov qis dua cov ntsiab lus nickel, qhov ntau dua ntawm manganese thiab nitrogen uas yuav tsum tau ntxiv. Piv txwv li, Hom 201 stainless hlau tsuas muaj 4.5% nickel thiab 0.25% nitrogen. Los ntawm kev sib npaug npib tsib xee, cov nitrogens sib npaug rau 7.5% npib tsib xee hauv lawv lub peev xwm tsim austenite, yog li 100% austenite qauv kuj tuaj yeem tsim. Qhov no kuj yog txoj cai tsim ntawm 200 series stainless hlau. Hauv qee qhov 200 series stainless hlau uas tsis ua raws li tus qauv, vim tsis muaj peev xwm ntxiv cov manganese thiab nitrogen txaus, thiaj li tsim tau 100% austenitic qauv, tus nqi ntawm chromium ntxiv yog txo qis, uas yuav ua rau inevitably ua rau. poob ntawm corrosion kuj ntawm stainless hlau. .
Hauv cov hlau tsis muaj steel, ob lub zog tawm tsam ua ib txhij: ferrite-forming ntsiab kom tsim ferrite, thiab austenite-forming ntsiab tseem ua austenite. Cov qauv siv lead ua zaum kawg nyob ntawm qhov txheeb ze ntawm ob hom ntawm cov khoom ntxiv. Chromium yog ib qho ferrite-forming caij, yog li chromium yog nyob rau hauv kev sib tw kev sib raug zoo nrog austenite-forming ntsiab nyob rau hauv tsim ntawm stainless hlau siv lead ua qauv. Vim hais tias hlau thiab chromium yog ob qho tib si ferrite-tsim cov ntsiab lus, 400 series stainless hlau yog tag nrho ferritic stainless hlau uas yog hlau nplaum. Nyob rau hauv tus txheej txheem ntawm ntxiv austenite-forming element-nickel rau hlau-chromium stainless hlau, raws li cov ntsiab lus nickel nce, cov austenite tsim yuav maj mam nce mus txog rau thaum tag nrho cov ferrite qauv yog hloov mus rau hauv austenite qauv, yog li tsim 300 series stainless hlau. Yog tias tsuas yog ib nrab ntawm cov nyiaj npib tsib xee ntxiv, 50% ferrite thiab 50% austenite yog tsim, ib qho qauv hu ua duplex stainless hlau.
400 series stainless hlau yog hlau, carbon-chromium alloy. Cov hlau stainless no muaj cov qauv martensitic thiab hlau, yog li nws muaj cov khoom sib nqus zoo li qub. 400 series stainless hlau muaj zog tiv taus kub oxidation, thiab piv nrog carbon steel, nws lub cev thiab txhua yam khoom muaj kev txhim kho ntxiv. Feem ntau 400 series stainless hlau tuaj yeem kho cua sov.
300 series stainless hlau yog cov khoom siv hlau uas muaj hlau, carbon, npib tsib xee thiab chromium, cov khoom siv hlau tsis sib nqus hlau, uas muaj cov khoom zoo tshaj li 400 series stainless hlau. Vim lub austenitic qauv ntawm 300 series stainless hlau, nws muaj zog corrosion kuj nyob rau hauv ntau qhov chaw, zoo tiv thaiv puas los ntawm corrosion tshwm sim los ntawm hlau overstress, thiab nws cov khoom siv tsis cuam tshuam los ntawm kev kho cua sov. Kev npam.