Yam cuam tshuam rau cov hlau tsis muaj steel

Txawm hais tias stainless hlau phaj los yog kub-resistant steel phaj, austenitic steel phaj muaj qhov zoo tshaj plaws kev ua tau zoo, nrog txaus lub zog, zoo heev plasticity, thiab tsawg hardness, uas kuj yog ib qho ntawm cov laj thawj vim li cas lawv tau dav siv. Austenitic stainless hlau zoo ib yam li lwm cov ntaub ntawv hlau nyob rau hauv cov nqe lus ntawm tensile lub zog, yield zog, thiab hardness, uas nce nrog qhov kub thiab txias; Plasticity txo nrog txo qhov kub thiab txias. Nws lub zog tensile nce kuj zoo ib yam nyob rau hauv qhov kub thiab txias ntawm 15-80 degree C. Qhov tseem ceeb tshaj, raws li qhov kub thiab txias, nws qhov cuam tshuam toughness txo qis thiab tsis muaj qhov hloov pauv kub. Yog li stainless hlau muaj peev xwm tswj tau cov yas txaus thiab toughness ntawm qhov kub thiab txias. Lub tshav kub tsis kam ntawm stainless hlau hais txog nws lub peev xwm los tiv thaiv oxidation lossis roj nruab nrab corrosion ntawm qhov kub thiab txias, uas tseem hu ua thermal stability.
Qhov cuam tshuam ntawm chromium
Chromium yog cov khoom tseem ceeb tshaj plaws nyob rau hauv austenitic stainless hlau, thiab qhov ua tiav ntawm nws cov xeb kuj thiab corrosion kuj yog vim cov nyhuv ntawm alloying, uas txhawb cov passivation ntawm hlau thiab ua rau nws nyob rau hauv ib tug ruaj khov thiab passive lub xeev. ○ 1 Cov nyhuv ntawm chromium ntawm microstructure: Hauv austenitic stainless hlau, chromium yog ib qho tseem ceeb uas tsim thiab ruaj khov ferrite, txo qhov austenite cheeb tsam. Raws li cov ntsiab lus hlau nce, ferrite tuaj yeem tshwm sim hauv austenitic stainless hlau ( δ ) Kev tshawb fawb tau pom tias nyob rau hauv chromium nickel austenitic stainless hlau, thaum cov ntsiab lus carbon yog 0.1 feem pua ​​thiab cov ntsiab lus chromium yog 18 feem pua, cov npib tsib xee. cov ntsiab lus yuav tsum tau kom tau ib tug ruaj khov austenitic qauv yog qhov qis tshaj, txog 8 feem pua. Hauv qhov no, feem ntau siv 18Cr-8Ni hom chromium nickel austenitic stainless hlau yog qhov haum tshaj plaws nrog chromium thiab npib tsib xee cov ntsiab lus piv. Nyob rau hauv austenitic stainless hlau, raws li cov ntsiab lus chromium nce, qee cov theem ntawm intermetallic (xws li δ Qhov kev xav ntawm theem nce, thiab thaum molybdenum muaj nyob rau hauv cov hlau, cov ntsiab lus chromium yuav nce χ Kev sib npaug, raws li tau hais ua ntej, σ , χ Cov nag lossis daus ntawm theem tsis tsuas yog txo cov plasticity thiab toughness ntawm hlau, tab sis kuj txo cov corrosion kuj ntawm cov hlau nyob rau hauv ib co tej yam kev mob. Yog li txhim kho kev ruaj ntseg ntawm austenitic matrix, yog li ntawd, nws yog ib qho nyuaj kom tau txais Martensite qauv rau siab chromium (xws li ntau tshaj 20 feem pua) austenitic stainless hlau txawm tias tom qab ua hauj lwm txias thiab tsis kub kho.
Chromium yog ib qho muaj zog carbide tsim, thiab nws tsis muaj qhov tshwj xeeb hauv austenitic stainless hlau. Feem ntau chromium carbides hauv austenitic stainless hlau muaj xws li Cr23C6; Thaum cov hlau muaj molybdenum los yog chromium, carbides xws li Cr6C tas sij hawm kuj tuaj yeem pom, thiab lawv cov tsim tuaj yeem cuam tshuam rau cov khoom ntawm cov hlau nyob rau hauv tej yam kev mob. ○ 2 Cov txiaj ntsig ntawm chromium ntawm kev ua tau zoo: Feem ntau hais lus, tsuav yog austenitic stainless hlau tuav cov qauv ua tiav austenitic yam tsis muaj δ Kev tsim cov ferrite thiab lwm yam tsis cuam tshuam rau cov khoom siv kho tshuab los ntawm tsuas yog nce cov ntsiab lus chromium hauv cov hlau. Qhov cuam tshuam loj tshaj plaws ntawm chromium rau cov khoom ntawm austenitic stainless hlau yog corrosion kuj, feem ntau yog manifested li: chromium txhim kho oxidation tsis kam ntawm cov hlau nruab nrab thiab kev ua tau zoo ntawm acidic chloride nruab nrab; Raws li kev sib xyaw ua ke ntawm npib tsib xee, molybdenum, thiab tooj liab, chromium txhim kho cov hlau tsis muaj zog los txo cov xov xwm xws li organic acids, urea, thiab alkaline media; Chromium kuj tseem txhim kho qhov tsis kam ntawm cov hlau rau hauv zos corrosion, xws li intergranular corrosion. Pitting corrosion, Crevice corrosion thiab kev nyuaj siab corrosion kev ua tau zoo nyob rau hauv tej yam kev mob.