17-4PH (630) Stainless Hlau: Cov Nroj Tsuag Ntau Yam-Hardening Alloy

 

Dab tsi yog cov tshuaj muaj pes tsawg leeg, tshwj xeeb ua kom zoo dua, thiab kev siv thawj zaug ntawm 17-4PH?
Nws muaj pes tsawg leeg muaj xws li ~ 15-17.5% Cr, 3-5% Ni, 3-5% Cu, thiab 0.15-0.45% Nb/Cb. Tus yuam sij rau nws cov khoom yog cov ntsiab lus tooj liab. Nws yog muab nyob rau hauv ib tug tov-kho (Cov Cai A) lub xeev, uas yog kuj mos thiab machinable. Tom ntej no-kub qis "aging" tshav kub kho precipitates nplua tooj liab hais, ua kom muaj zog nrog tsawg distortion. Qhov no tso cai rau complex qhov chaw yuav tsum machined ua ntej hardening. Cov khoom siv tseem ceeb suav nrog cov khoom siv dav hlau, turbine hniav, twj tso kua mis, lub zog, cov khoom siv hluav taws xob, pwm, thiab cov khoom siv muaj zog.

Cov txheej txheem nag lossis daus ua haujlwm li cas, thiab cov txheej txheem kev laus yog dab tsi?
Tom qab cov tshuaj kho thiab txias, cov hlau yog nyob rau hauv lub xeev martensitic. Kev laus ntawm 480-620℃(900-1150℃F) ua rau cov tooj liab supersaturated precipitate zoo li zoo, sib npaug sib npaug. Cov khoom no impede dislocation txav, ntxiv dag zog rau cov hlau. Cov xwm txheej muaj xws li H900 (hnub nyoog ntawm 900℃F), uas muab lub zog siab tshaj plaws (txog HRC 44) tab sis qis zog; H1025 thiab H1075 muaj cov khoom nruab nrab; thiab H1150 muab qhov zoo tshaj plaws toughness thiab kev nyuaj siab corrosion cracking kuj ntawm qis zog. Qhov xwm txheej raug xaiv raws li qhov xav tau ntawm cov cuab yeej tshuav.

Dab tsi yog qhov kev tiv thaiv corrosion thiab txhua yam khoom ntawm 17-4PH?
Nws cov corrosion kuj feem ntau piv rau Hom 304 stainless hlau nyob rau hauv ntau atmospheric, dej tshiab, thiab me me tshuaj ib puag ncig. Nws tsis zoo li corrosion-resistant li 316 hauv chlorides. Mechanically, tom qab kev laus, nws muaj peev xwm ua tau lub zog tensile tshaj 1300 MPa (190 ksi). Nws tuav zoo toughness thiab qaug zog. Nws tiv thaiv kev ntxhov siab corrosion tawg yog qhov zoo nyob rau hauv cov neeg laus tshaj - cov neeg laus (xws li H1150) tab sis tuaj yeem muaj kev txhawj xeeb hauv qhov siab tshaj - lub zog (xws li H900) hauv qee qhov chaw.

Hauv kev lag luam twg thiab cov ntawv thov tshwj xeeb yog 17-4PH ib qho kev xaiv cov khoom tseem ceeb?
Nws yog qhov tseem ceeb nyob rau hauv aerospace rau tsaws iav Cheebtsam, actuator qhov chaw, thiab cav mounts vim nws siab zog - mus rau - luj piv. Hauv kev lag luam tshuaj thiab roj & roj, nws yog siv rau li qub, shafts, thiab fittings xav tau lub zog thiab nruab nrab corrosion kuj. Kev lag luam kho mob siv nws rau cov cuab yeej phais thiab kev cog qoob loo. Nws kuj tau dav siv rau cov yas txhaj tshuaj pwm, tuag-casting tooling, thiab siab-kev ua kis las khoom siv qhov chaw hardness thiab polishability.

Dab tsi yog qhov tseem ceeb rau kev siv tshuab, vuam, thiab kev yuav khoom 17-4PH?
Machining:Ua tau zoo tshaj plaws hauv kev daws teeb meem - kho mob A.Vuam:Muaj peev xwm siv qhov sib txuam 17-4PH muab tub lim, tab sis yuav tsum tau ua hauv kev daws teeb meem- kho mob. Tag nrho cov kev sib dhos ces yuav tsum muaj kev daws teeb meem tag nrho thiab lub hnub nyoog voj voog kom rov zoo li qub; kev laus hauv zos ntawm ib qho kev sib txuas tsis zoo.Kev yuav khoom:Qhia qhov xwm txheej uas yuav tsum tau ua (xws li, Txoj Cai A rau kev tsim khoom, lossis Txoj Cai H900 rau cov khoom tiav). Cov ntaub ntawv xeem Mill yuav tsum paub meej txog chemistry, tshwj xeeb tshaj yog tooj liab thiab niobium. Ua haujlwm ze nrog tus kws kho cua sov uas tsim nyog, vim tias cov khoom yog nyob ntawm qhov tseeb thermal ua.