630 (17-4 PH) vs 631 (17-7 PH) Precipitation-Hardening Stainless Steels: Strength vs Toughness

 

Dab tsi yog lawv cov ntsiab lus tseem ceeb thiab cov cuab yeej cuab tam tseem ceeb sib txawv?

630 (17-4 PH) muaj 15–17.5% Cr, 3–5% Ni, 3–5% Cu, 0.15–0.45% Nb, nrog Tsawg dua los yog sib npaug rau 0.07% C. Hauv H900 tshav kub- kho mob, nws ua tiav lub zog ntawm RC 3 thiab a 10 yield ntsuas lub zog thiab ductility rau kev lag luam use.631 (17-7 PH) nta 16–18% Cr, 6.5–7.75% Ni, 0.75–1.5% Al, nrog tsawg dua lossis sib npaug li 0.09% C, thiab tsis muaj tooj liab lossis niobium. Nws TH1050 kev kho cua sov yields lub siab tshaj plaws ntawm ~ 1380 MPa thiab 42 HRC, nrog tshwj xeeb toughness ntawm subzero kub mus rau -200℃.Ob qib yog non-sib nqus nyob rau hauv cov tshuaj-annealed xeev thiab ua hlau nplaum tom qab nag lossis daus hardening.

Lawv cov txheej txheem kho cua sov txawv li cas rau kev ua haujlwm zoo?

Rau 630, tus qauv H900 lub voj voog yog: tshuaj anneal ntawm 1040 degree, quench mus rau chav tsev kub, ces muaj hnub nyoog ntawm 480℃rau 1 teev kom muaj zog. Kev laus ntawm qhov kub siab dua (piv txwv li, 620℃rau H1150) txo lub zog tab sis txhim kho corrosion kuj thiab toughness.631 yuav tsum muaj ob - cov txheej txheem rau kev ua haujlwm siab: tshuaj anneal ntawm 1065℃, quench mus rau chav tsev kub, ces muaj hnub nyoog ntawm 510℃rau 1 teev (TH1050 mob). Nws kuj tseem tuaj yeem ua kom txias- ua haujlwm ua ntej kev laus kom txhawb zog ntxiv los ntawm 10–15%. Ob qib yuav tsum tau muab tshuab rau hauv cov tshuaj -annealed xeev-lawv cov tawv tawv yog qhov nyuaj heev rau tshuab yam tsis muaj cuab yeej tshwj xeeb.

Nyob rau hauv daim ntawv thov twg yog ib qib irreplaceable dua lwm?

Xaiv 630 rau dav dav - lub zog, nruab nrab- daim ntawv thov corrosion: roj thiab roj downhole cov cuab yeej, valve stems, hydraulic cylinder rods, thiab kev kho mob cog (xws li, orthopedic screws) qhov twg biocompatibility thiab lub zog yog ib qho tseem ceeb.Opt rau 631 rau aerospace, kev tiv thaiv, thiab cryogenic iav. qhov chaw, satellite brackets, thiab kua natural gas (LNG) cov cuab yeej cia uas ntsib qhov kub thiab txias hloov pauv.631 kuj tseem nyiam rau siab - qhov kev pabcuam kub txog li 315℃, thaum 630 lub zog poob qis dua 260℃.

Lawv cov corrosion kuj piv rau lwm cov qib siab - zog li cas?

630 muaj corrosion kuj piv rau 304 stainless hlau, tiv taus atmospheric, dej tshiab, thiab tshuaj lom neeg corrosion. Nws ua tau zoo nyob rau hauv oilfield brines tab sis tsis pom zoo rau marine ib puag ncig yam tsis muaj kev tiv thaiv coatings.631 cov ntsiab lus chromium siab dua muab nws cov tshuaj chloride zoo me ntsis dua li 630, zam luv luv -lub sij hawm ntsev tsuag tshuaj nyob rau hauv ntug dej hiav txwv aerospace chaw. Nws tseem poob qis ntawm 316L's marine corrosion kuj.Ob qib ua tau zoo dua qib martensitic zoo li 410 thiab 420 hauv corrosive chaw, tab sis tsis tshua muaj resistant dua duplex stainless hlau (xws li, 2205) rau hnyav industrial puag ncig.

Tus nqi thiab kev tsim khoom lag luam yog dab tsi- tawm ntawm ob qib?

630 yog 15-20% pheej yig dua 631, ua rau nws tus nqi -kev xaiv zoo rau tsis yog{5}}aerospace siab- daim ntawv thov muaj zog. Nws cov ntsiab lus tooj liab kuj tseem txhim kho kev ua haujlwm zoo dua piv rau 631.631 muaj qhov tsim qis dua 630 vim nws cov ntsiab lus nickel thiab txhuas ntau dua, yuav tsum tau siv zog ntau dua rau kev khoov thiab sib sib zog nqus nqus kom tsis txhob tawg.Vuam yog tsis pom zoo rau qhov tseem ceeb ntawm kev thauj khoom ntawm ob qib - vuam cuam tshuam, kev cuam tshuam ntawm microstructure {13}. cua sov{14}} thaj tsam cuam tshuam los ntawm 30–40%.