430 vs 431 Stainless hlau: Ferritic vs Martensitic Qib

 

Dab tsi yog cov tshuaj muaj pes tsawg leeg, cov khoom siv kho tshuab, thiab cov ntawv thov tseem ceeb ntawm 430 thiab 431 stainless hlau?
Qib 430 (UNS S43000) yog ferritic stainless hlau, muaj li ntawm 16-18% chromium nrog tsawg carbon thiab tsis muaj npib tsib xee. Nws yog hlau nplaum, muaj zog nruab nrab thiab zoo ductility, thiab tsis hardenable los ntawm kev kho cua sov. Nws feem ntau yog siv rau hauv cov khoom siv sab hauv, cov khoom siv kho kom zoo nkauj hauv tsheb, chav ua noj splashbacks, thiab fasteners hauv qhov chaw me me. Qib 431 (UNS S43100) yog martensitic stainless hlau, muaj 15-17% chromium thiab 1.25-2.50% nickel. Nws tuaj yeem hardened los ntawm quenching thiab tempering kom ua tau siab zog thiab hardness. Nws cov ntawv thov tseem ceeb suav nrog cov khoom siv muaj zog, cov twj tso kua mis, cov khoom siv lub cev, thiab cov khoom siv dav hlau uas xav tau kev sib xyaw ua ke ntawm lub zog thiab kev tiv thaiv corrosion.

Lub peev xwm kho cua sov ntawm 431 tau hloov pauv nws qhov kev ua tau zoo li cas piv rau 430?
Lub peev xwm los kho cua sov 431 yog nws tus yam ntxwv txhais. Tom qab austenitizing thiab quenching, 431 tsim ib qho nyuaj martensitic qauv uas tuaj yeem tempered kom ua tiav ntau theem ntawm lub zog thiab toughness. Qhov no tso cai rau nws ncav cuag lub zog tensile zoo tshaj 1000 MPa thiab hardness mus txog HRC 44, muab kev hnav zoo heev. Hauv qhov sib piv, 430 tsis tuaj yeem ntxiv dag zog los ntawm kev kho cua sov; nws cov khoom yog tsau nyob rau hauv lub xeev annealed, muab tsuas yog nruab nrab lub zog. Qhov no ua rau 431 haum rau cov qauv thiab hnav cov khoom, thaum 430 tsuas yog txwv tsis pub- thauj khoom- cov kabmob, feem ntau yog cov khoom siv zoo nkauj lossis cladding.

Nyob rau hauv cov nqe lus ntawm corrosion kuj, ob qib no piv li cas, thiab dab tsi ib puag ncig haum rau txhua tus?
430 muaj qhov zoo corrosion kuj nyob rau hauv me me atmospheric, dej tshiab, thiab sab hauv tsev ib puag ncig, piv rau 304 rau ntau yam uas tsis yog - daim ntawv thov tseem ceeb. Txawm li cas los xij, nws muaj kev cuam tshuam rau pitting hauv cov tshuaj chloride-muaj cov chaw. 431, tom qab kev kho cua sov kom zoo thiab polishing, muaj corrosion kuj zoo nyob rau hauv ib puag ncig me me mus rau nruab nrab, feem ntau zoo dua 410 vim nws cov ntsiab lus chromium thiab nickel ntau dua. Txawm li cas los xij, nws qhov kev tiv thaiv corrosion feem ntau tsis zoo li 430 nyob rau hauv tib yam kev mob . 430 yog haum rau sab hauv tsev fixtures thiab qhuav sab nrauv trim, thaum 431 raug xaiv rau qhov chaw uas yuav tsum tau muaj zog nyob rau hauv me me corrosive chaw, xws li marine hardware los yog tshuaj twj tso kua mis Cheebtsam.

Dab tsi yog qhov txawv ntawm machinability, weldability, thiab formability ntawm 430 thiab 431?
430 muaj formability zoo heev thiab tuaj yeem yooj yim sib sib zog nqus nqus, khoov, thiab spun, zoo ib yam li cov hlau me me. Nws machinability yog ncaj ncees, tab sis nws cov weldability yog txwv; welding tuaj yeem ua rau cov qoob loo loj hlob thiab txo cov corrosion kuj nyob rau hauv tshav kub - cuam tshuam cheeb tsam . 431 muaj tsawg formability, tshwj xeeb tshaj yog nyob rau hauv lub hardened xeev, thiab nws machinability yog ncaj ncees nyob rau hauv lub annealed mob tab sis yuav tsis zoo tom qab hardening. Vuam 431 yuav tsum tau preheating thiab post-welding thaum tshav kub kub kev kho mob kom tsis txhob tawg thiab rov qab corrosion kuj. Rau fabrication nrog txoj kev sib sau, 430 yog qhov zoo dua; rau siab - lub zog welded qauv, 431 yuav tsum tau ceev faj ntau dua cov txheej txheem thiab thermal tswj.

Raws li tus tsim qauv lossis tus neeg yuav khoom, dab tsi yuav tsum txiav txim siab xaiv ntawm 430 thiab 431 stainless hlau?
Qhov kev xaiv yuav tsum tau tsav los ntawm kev ua haujlwm tseem ceeb thiab qhov chaw ua haujlwm. Xaiv 430 thaum daim ntawv thov xav tau kev tiv thaiv corrosion zoo, tus nqi qis, thiab yooj yim formability rau cov khoom tsis yog - cov khoom siv, xws li cov vaj huam sib luag zoo nkauj, luas, lossis cov khoom siv sab hauv. Xaiv 431 thaum cov khoom tivthaiv yuav tsum tiv taus cov neeg kho tshuab siab, hnav, lossis kev poob siab hauv qhov chaw me me, xws li hauv cov fasteners, shafts, lossis valve qhov chaw. Nco ntsoov xav txog tag nrho lub neej voj voog: yog tias qhov yuav tsum tau hardened tom qab machining, 431 yog tsim nyog; Yog tias nws yuav raug welded thiab raug huab cua, cov kev txwv ntawm ob qib yuav tsum tau ua tib zoo soj ntsuam, thiab lwm txoj kev xws li 304 lossis 316 yuav tsim nyog dua.