Martensitic stainless steels muaj ib lub cev-centered cubic siv lead ua qauv, thiab muaj ntau yam khoom thiab yog siv los ua stainless engineering steels, stainless hlau cuab yeej, thiab creep-resistant steels. Lawv yog cov hlau nplaum, thiab tsis zoo li corrosion-resistant li ferritic thiab austenitic stainless hlau vim lawv cov ntsiab lus chromium tsawg. Lawv poob rau hauv plaub pawg (nrog qee qhov sib tshooj):
Fe-Cr-C qib.Cov no yog thawj qib siv thiab tseem siv dav hauv engineering thiab hnav-resistant daim ntaub ntawv.
Fe-Cr-Ni-C qib.Qee cov pa roj carbon yog hloov los ntawm nickel. Lawv muaj ntau dua toughness thiab ntau dua corrosion kuj. Qib EN 1.4303 (Casting qib CA6NM) nrog 13 feem pua Cr thiab 4 feem pua Ni yog siv rau feem ntau Pelton, Kaplan, thiab Francis turbines hauv hydroelectric fais fab nroj tsuag vim nws muaj zoo casting zog, zoo weldability thiab zoo tiv thaiv cavitation yaig.
Cov qib nag lossis daus hardening.Qib EN 1.4542 (tseem hu ua 17/4PH), qib zoo tshaj plaws-paub, sib txuas martensitic hardening thiab nag lossis daus hardening. Nws ua tiav lub zog siab thiab zoo toughness thiab siv nyob rau hauv aerospace ntawm lwm yam kev siv.
Cov qib Creep-resisting.Ntxiv me me ntawm niobium, vanadium, boron, thiab cobalt nce lub zog thiab nkag siab txog li 650 degree (1,202 degree F).
Martensitic stainless hlau tuaj yeem kho cua sov kom muab cov khoom zoo dua qub. Kev kho cua sov feem ntau muaj peb kauj ruam:
Austenitizing,nyob rau hauv uas cov hlau yog rhuab mus rau ib tug kub ntawm 980-1,050 degree (1,800-1,920 degree F), nyob ntawm seb qib. Cov txiaj ntsig austenite muaj lub ntsej muag-centered cubic crystal qauv.
Quenching.Lub austenite tau hloov mus rau hauv martensite, lub cev tawv-centered tetragonal siv lead ua qauv. Lub quenched martensite yog ib qho nyuaj heev thiab nkig heev rau feem ntau daim ntawv thov. Qee qhov residual austenite yuav nyob twj ywm.
Tempering.Martensite yog rhuab mus txog 500 degree (932 degree F), tuav ntawm qhov kub thiab txias, ces cua txias. Kev kub siab kub txo qis zog thiab qhov kawg tensile lub zog tab sis ua rau kom elongation thiab cuam tshuam tsis kam.
Hloov qee cov pa roj carbon monoxide hauv martensitic stainless hlau los ntawm nitrogen yog qhov kev txhim kho tsis ntev los no. Cov hlau uas muaj txog li 0.4 feem pua nitrogen tau ua tiav, ua rau muaj zog dua thiab muaj zog thiab muaj zog dua corrosion. Raws li PESR yog kim, qis dua tab sis tseem ceeb cov ntsiab lus nitrogen tau ua tiav siv tus txheej txheem argon oxygen decarburization (AOD).
