Peb cuam tshuam nrog stainless hlau tas li-los ntawm chav ua noj cookware thiab dav hlau cav hniav mus rau siab -siab li qub nyob rau hauv tob- hiav txwv roj thiab roj teb. Tseem, koj puas tau pom? Thaum "annealing" los txog, ntau tus neeg thawj qhov kev xav yog qhov kev xav ntawm carbon steel: "heat nws liab-kub thiab cia nws txias maj mam." Kuv tau pom deb dhau lawm ntau tus neeg dawm rau hauv qhov ntxiab no. Stainless hlau coj txawv txawv kiag li ntawm carbon hlau. Austenitic, ferritic, duplex, martensitic, nag lossis daus - hardening ... yog tias koj twv kho tsib hom stainless hlau nrog tib qhov kub thiab txias, qhov zoo tshaj plaws - xwm txheej yog kev cuam tshuam kev ua tau zoo, thiab qhov phem tshaj yog scrapping tag nrho cov khoom. Hnub no, kuv tab tom qhia kuv "secret stash" ntawm cov txheej txheem tsis ua haujlwm-tsis muaj fluff, tsuas yog siv tau, khw- pem teb-npaj paub- yuav ua li cas. Xav tias dawb rau bookmark qhov no, tab sis ua tib zoo nyeem-vim txhua tus lej sawv cev rau zaj lus qhia uas tau kawm nyuaj. Ua ntej, cia peb saib cov qauv universal kom koj tsis txhob poob siab ntawm tus puav. Txawm li cas los xij ntawm hom stainless hlau, muaj ib txoj hauv kev los xam lub sijhawm tuav: ** Lub Sijhawm Tuav=Ua Haujlwm Thickness ntawm Workpiece × Tuav Coefficient **. Cias muab tso, coj lub thickness (hauv millimeters) ntawm ib feem ntawm qhov thickest seem thiab muab nws los ntawm ib tug coefficient. Koj xaiv qhov coefficient li cas? Rau cov qauv, siv 0.8 mus rau 1.2 feeb ib millimeter; rau tuab lossis welded qhov chaw, tsoo nws mus txog 1.2-1.5 kom paub meej meej kev ntxhov siab; rau precision nyias-walled qhov chaw, 0.6-0.8 txaus. Khaws qhov no hauv siab-koj yuav xav tau nws rau txhua hom hlau uas peb tham. **1. Austenitic Stainless Steel (304, 316, 321)**: Cov no yog hom ntau tshaj plaws -non-sib nqus thiab tawv-tab sis lawv muaj ib qho tsis muaj zog loj: susceptibility rau "sensitization." Dab tsi yog rhiab heev? Nws tshwm sim thaum cov khoom siv sij hawm ntau dhau ntawm 425℃-870℃ntau yam; chromium tsiv tawm mus rau kev sib raug zoo nrog cov pa roj carbon monoxide, ua rau cov khoom muaj kev cuam tshuam rau hauv cheeb tsam corrosion. Yog li, txoj cai golden ntawm annealing ntawm no yog qhov yooj yim: mus qis lossis mus siab -tsuas yog tsis txhob nyob hauv nruab nrab. ** Tsawg-qhov kub thiab txias (320-360 degree)**: Haum rau qhov tseeb thiab nyias- cov khoom siv phab ntsa. Siv cov khoom tuav ntawm 1.0. Nyob rau ntawm qhov kub thiab txias no, kev ntxhov siab yog relieved nrog zoo tsis muaj deformation, thaum hardness thiab corrosion kuj yog tswj. Yuav ua li cas txias? Cias cia qhov txias maj mam nyob rau hauv lub qhov cub kom qis dua 200℃ua ntej tshem nws rau cua txias. Tsis txhob quench nws sai, los yog kev ntxhov siab yuav rov qab los. Siab -qhov kub thiab txias (850-900 degree): tshwj xeeb tshaj yog rau cov khoom siv welded thiab cov phaj tuab. Nws tshem tawm tag nrho cov kev ntxhov siab uas tshwm sim los ntawm kev vuam. Nco ntsoov txoj cai nruj no: tsis txhob tuav qhov kub ntawm 500℃thiab 700℃rau lub sijhawm ntev! Qhov no yog qhov chaw txaus ntshai rau intergranular corrosion; Muaj ntau qhov tsis txaus ntseeg cov kav dej xau los ntawm qhov tseeb qhov teeb meem no. 2. Ferritic stainless hlau (430, 409, 439): Cov hlau no muaj cov thermal conductivity zoo thiab tus nqi qis, tab sis lawv nkig thiab muaj qhov tsis muaj zog txaus tuag-lawv yog cov qoob loo loj hlob ntawm qhov kub thiab txias. Thaum qhov kub siab tshaj 850 degree, cov nplej loj hlob sai, ua rau cov khoom tsis tshua muaj nkig. Qhov kev ntxhov siab-relief annealing kub yog 750-850 degree, feem ntau yog siv los daws cov kev ntxhov siab sab hauv sab laug tom qab khoov lossis stamping. Siv qhov ntsuas tuav ntawm 0.9 feeb ib millimeter. Tom qab tuav, koj tuaj yeem txias qhov chaw hauv qhov cub lossis hauv huab cua- nws tsis muaj teeb meem ntau. Txawm li cas los xij, nco ntsoov: qhov kub yuav tsum tsis pub tshaj 850 degree. Txawm tias ib qib siab dua ua rau cov qoob loo loj tuaj; Thaum coarsening tshwm sim, nws yog irreversible, thiab ib feem yuav tsum tau muab pov tseg. Tsis tas li ntawd, tsis txhob thab sim qis-kub, ntev-lub sij hawm annealing; nws tsis muaj txiaj ntsig. Kev ntxhov siab rau kev ua haujlwm yog qhov tsis tshua muaj qhov kub thiab txias rau cov hlau no -nws yog qhov ua tiav ntawm lub sijhawm. 3. Duplex stainless hlau (2205, 2507): Cov no yog cov hlau zoo nkauj, sib txuas cov tawv tawv ntawm austenite nrog lub zog ntawm ferrite thiab muab kev tiv thaiv zoo rau pitting corrosion. Txawm li cas los xij, lawv muaj qhov ua kom yuam kev-lawv kub hnyiab heev-sensitive. Tag nrho cov kev ntxhov siab-relief annealing yuav tsum tau kub siab, tshwj xeeb tshaj yog 1020-1100℃. Qhov ntsuas kub no rebalances qhov piv ntawm ob theem thiab tso tawm tag nrho cov kev ntxhov siab vim los ntawm vuam. Siv cov khoom tuav ntawm 1.2, lossis nce nws mus rau 1.5 rau tuab-cov khoom siv phab ntsa welded. Ntawm no yog qhov tseem ceeb: tom qab lub sijhawm tuav, kev ua kom txias sai thiab zoo ib yam yog qhov tseem ceeb- nrawm dua, zoo dua - txhawm rau tiv thaiv kev tsim ntawm kev puas tsuaj sigma (σ) theem. Tuav cov khoom ntawm qhov kub ib ncig ntawm 900℃yog nruj me ntsis txwv! Qhov ntsuas kub no yog "lub vaj kaj siab" rau theem sigma; Thaum nws precipitates, cov khoom yuav nkig li iav, thiab nws cov corrosion kuj plummets. Tau kawg, rau nyias-cov phab ntsa, qhov qis- kho qhov kub thiab txias (320–360 degree)-zoo ib yam li cov siv rau austenitic steels- qee zaum ua haujlwm los daws qhov kev ntxhov siab siab, tab sis cov no tsuas yog kev ntsuas kev txwv tsis pub muaj qhov tsis sib haum xeeb uas tsis daws qhov teeb meem ntawm cov hauv paus hniav. (410, 420, 431): Cov ntaub ntawv no yog siv los txiav cov cuab yeej thiab cov kabmob vim lawv cov tawv tawv thiab hnav tsis kam. Txawm li cas los xij, lawv tsim muaj kev ntxhov siab sab hauv tom qab quenching thiab nquag ua kom tawg yog tias tsis kho. Qhov kev ntxhov siab{119}}relief temperature range yog 300–400℃. Tsis txhob raug dag los ntawm qhov kub thiab txias; nws yog raws nraim. Siv lub sijhawm tuav ntawm 1.0 feeb ib millimeter tuab, ua raws li cua txias. Qhov ntsuas kub no tau zoo tshem tawm cov kev ntxhov siab los ntawm kev siv tshuab lossis kev sib tsoo thaum khaws cov khoom siv siab hardness. Nws muaj qhov kub thiab txias "zones txaus ntshai" kom zam: 350-550℃. Tempering nyob rau hauv qhov ntau yam no induces "temper brittleness," ua rau poob qis hauv kev cuam tshuam toughness. Es tsis txhob ua ob qho tib si tawv thiab tawv, cov khoom yuav nyuaj tsis tau nkig, snapping raws li kev cuam tshuam. Qhov no yog qhov chaw qub nrog martensitic stainless hlau{132}} nag lossis daus-cov hlau tsis muaj zog (17-4PH, 15-5PH): Siv dav hauv aerospace applications thiab siab{142}}kawg pwm, cov hlau no tau txais lawv lub zog ntawm micros machining theem. Lub logic rau annealing lawv yog qhov sib txawv ntawm cov piv txwv yav dhau los. Lub hauv paus ntsiab lus tseem ceeb yog tias qhov kub ntawm qhov annealing yuav tsum tsis txhob dhau qhov kub ntawm kev laus, vim tias cov txheej txheem kev laus tseem ceeb heev rau cov khoom kom ua tiav nws cov khoom kawg. Yog hais tias qhov kub thiab txias ua rau lub zog ua kom muaj zog los nag ntxov ntxov, tom qab kev laus kho kom zoo yuav tsis zoo, thiab qhov kawg ntawm lub zog thiab qhov ntev yuav tsis ua raws li cov qauv tsim. Lub pre{150}}kev nyuaj siab{152}}relief kub feem ntau yog 480–550 degree, nrog rau qhov tuav ntawm 1.1, ua raws li qhov cub txias. Qhov ntsuas kub no yog qhov txaus los tshem tawm cov kev ntxhov siab los ntawm kev ua haujlwm ua ntej yam tsis tau ua rau cov nag lossis daus ntxov ntawm cov theem ntxiv. Xav txog qhov no: Koj muaj qhov precision ncej ua los ntawm 17-4 PH stainless hlau. Tom qab machining, nws tau deformed dhau qhov kev txwv tsis pub dhau, thiab koj xav siv high-temperature annealing kom ncaj nws. Koj yuav ua li cas? Koj puas yuav muaj kev pheej hmoo siab tshaj qhov kub thiab txias, lossis nrhiav lwm txoj kev daws teeb meem? Hauv kev tsim khoom, dab ntxwg nyoog yog nyob rau hauv cov ntsiab lus-tab sis qhov ntawd kuj yog qhov kev txawj ntse tseeb. Kuv vam tias tsab xov xwm no yuav ua rau koj muaj kev ntseeg siab ntxiv rau lub sijhawm tom ntej koj ua haujlwm stainless hlau qhov chaw. Nco ntsoov: tsis muaj kev txaj muag thaum nug cov lus nug thaum koj tsis paub ib yam dab tsi; qhov kev txaj muag tiag tiag los ntawm kev rhuav tshem ib feem thiab yuav tsum tau rov ua dua.
