Cov khoom siv hlau yog cov txheej txheem ua haujlwm feem ntau ua tiav los ntawm lub tshuab ua haujlwm 1580. Txhawm rau ua kom cov hlau ua haujlwm muaj qhov xav tau cov khoom siv dag zog, lub cev lub cev thiab cov khoom siv tshuaj lom neeg, ntxiv rau qhov tsim nyog xaiv cov ntaub ntawv thiab ntau yam txheej txheem tsim, txheej txheem kho cua sov yog feem ntau indispensable. Hlau yog cov khoom siv dav tshaj plaws hauv kev lag luam tshuab. Cov microstructure ntawm cov hlau yog qhov nyuaj thiab tuaj yeem tswj tau los ntawm kev kho cua sov. Yog li ntawd, kev kho cua sov ntawm cov hlau yog cov ntsiab lus tseem ceeb ntawm kev kho cua sov hlau. Ib qho ntxiv, txhuas, tooj liab, magnesium, titanium, thiab lwm yam thiab lawv cov hlau tuaj yeem hloov pauv lawv cov khoom siv dag zog, lub cev thiab tshuaj lom neeg los ntawm kev kho cua sov kom tau txais cov khoom sib txawv.
Kev kho cua sov feem ntau tsis hloov pauv cov duab ntawm cov khoom ua haujlwm thiab cov tshuaj lom neeg tag nrho, tab sis los ntawm kev hloov pauv cov txheej txheem sab hauv ntawm lub cev ua haujlwm, lossis hloov cov tshuaj lom neeg muaj pes tsawg leeg ntawm qhov chaw ua haujlwm, los muab lossis txhim kho kev ua haujlwm ntawm lub cev. Nws tus yam ntxwv yog txhawm rau txhim kho kev ua haujlwm sab hauv zoo, uas feem ntau tsis pom rau qhov muag liab qab.
Dab tsi yog txheej txheem ntawm kev kho cua sov hlau, cia' thawj zaug saib ntawm daim duab qhia chaw hauv qab no:
Qhov tseeb, lub luag haujlwm ntawm kev kho cua sov yog txhawm rau txhim kho cov khoom siv dag zog ntawm cov khoom siv, tshem tawm cov kev nyuab siab uas seem thiab txhim kho kev ua haujlwm ntawm cov hlau. Raws li lub hom phiaj sib txawv ntawm kev kho cua sov, cov txheej txheem kho cua sov tuaj yeem faib ua ob pawg: kev kho cua sov ua ntej thiab kev kho cua sov zaum kawg.
1. Kev kho cua sov ua ntej
Lub hom phiaj ntawm kev kho cua sov ua ntej yog txhawm rau txhim kho kev ua tiav, tshem tawm kev ntxhov siab sab hauv thiab npaj cov qauv hlau zoo rau kev kho cua sov zaum kawg. Cov txheej txheem kho cua sov suav nrog ua kom sov, ua kom zoo dua qub, laus dua, ua kom sov thiab ua kom sov, thiab lwm yam.
(1) Annealing thiab normalizing
Kev tshem tawm thiab ua kom zoo li qub tau siv rau qhov ua tiav cov txheej txheem kub. Cov pa roj carbon hlau thiab cov hlau hlau nrog cov ntsiab lus carbon ntau dua 0.5% feem ntau tau muab tshuaj txhuam txhawm rau txhawm rau txo lawv cov tawv thiab yooj yim txiav; carbon hlau thiab hlau hlau nrog cov ntsiab lus carbon tsawg dua 0.5% tau siv kom tsis txhob lo thaum lub zog hnyav dhau. Es tsis txhob, normalizing yog siv. Kev tshem tawm thiab ua kom zoo li qub tseem tuaj yeem ua kom zoo dua cov nplej thiab cov qauv zoo sib xws, npaj rau kev kho cua sov tom ntej. Kev tshem tawm thiab ua kom rov zoo li qub feem ntau tau teeb tsa tom qab qhov khoob tau tsim thiab ua ntej cov tshuab ntxhib.
(2) Kev kho neeg laus
Kev kho cov laus feem ntau yog siv los tshem tawm cov kev nyuaj siab sab hauv uas tsim los ntawm kev tsim khoom thiab ua haujlwm.
Txhawm rau zam kev thauj mus los ntau dhau ntawm kev ua haujlwm, rau ntu nrog qhov dav dav, kev kho neeg laus tuaj yeem npaj ua ntej ua tiav. Txawm li cas los xij, rau ntu uas muaj qhov yuav tsum tau ua kom siab dua (xws li lub thawv ntawm lub tshuab ua haujlwm sib tsoo, thiab lwm yam), yuav tsum tau teem ob lossis ntau txoj hauv kev kho cov laus. Feem ntau cov khoom yooj yim feem ntau tsis xav tau tshwj tsis yog rau cov castings. Rau qee qhov tshwj xeeb nrog qhov tsis zoo (xws li cov ntsia hlau tsis raug), txhawm rau tshem tawm qhov kev ntxhov siab sab hauv tsim thaum ua thiab ua kom lub tshuab ua haujlwm raug ntawm cov ntu, nws feem ntau tau teeb tsa ntawm kev ua haujlwm ntxhib thiab ib nrab ua tiav. Kev kho ntau yam kev laus. Rau qee qhov ua ntu ntu, kev kho cov laus yuav tsum tau npaj tom qab txheej txheem ncaj.
(3) Tempering
Kev ua kom sov thiab ua kom sov yog qhov kub ua kom sov tom qab quenching. Nws tuaj yeem tau txais cov qauv zoo thiab ua kom lub cev zoo sorbite los npaj rau kev txo qis ntawm kev hloov pauv thaum lub sij hawm tom ntej quenching thiab kho nitriding. Yog li ntawd, quenching thiab kub kuj tuaj yeem siv ua qhov kev kho cua sov ua ntej.
Vim yog qhov ua tau zoo tshaj plaws cov cuab yeej khoom ntawm qhov chaw tom qab quenching thiab kub, qee qhov uas tsis xav tau qhov hnyav thiab hnav tsis kam kuj tseem tuaj yeem siv ua txheej txheem kho cua sov zaum kawg.
2. Kev kho cua sov zaum kawg
Lub hom phiaj ntawm kev kho cua sov zaum kawg yog txhawm rau txhim kho cov khoom siv dag zog xws li tawv, hnav tsis kam thiab lub zog.
(1) Kev txiav tawm
Kev tua hluav taws suav nrog kev tua hluav taws thiab kev tua hluav taws tag nrho. Ntawm lawv, cov nplaim hluav taws tau siv dav vim yog kev hloov pauv me me, oxidation thiab decarburization, thiab cov nplaim hluav taws kub kuj tseem muaj qhov zoo ntawm lub zog sab nraud siab thiab tiv taus kev ua haujlwm zoo, thaum tswj tau zoo sab hauv thiab muaj zog tiv taus. Txhawm rau txhawm rau txhim kho cov khoom siv dag zog ntawm qhov chaw tawv tawv, kev kho cua sov xws li ua kom sov thiab ua kom sov lossis ua kom zoo yog feem ntau xav tau ua ntej kho cua sov. Cov txheej txheem txheej txheem dav dav yog: blanking-forging-normalizing (annealing) -bearning-quenching thiab tempering-semi-finishing-deg quenching-finishing.
(2) Carburizing thiab quenching
Carburizing thiab quenching yog haum rau cov pa roj carbon tsawg thiab cov hlau tsis tshua muaj hlau. Ua ntej, nce cov ntsiab lus carbon ntawm txheej txheej ntawm ntu. Tom qab quenching, txheej saum npoo yuav tau txais qhov nyuaj, thaum lub hauv paus tseem tseem tswj hwm qee lub zog thiab siab tawv thiab yas. Carburizing tau muab faib ua carburizing tag nrho thiab ib nrab carburizing. Nyob rau hauv cov ntaub ntawv ntawm ib nrab carburizing, anti-seepage ntsuas (tooj liab plating lossis anti-seepage khoom plating) yuav tsum tau noj rau qhov tsis-carburized ib feem. Txij li cov carburizing thiab quenching deformation loj, thiab carburizing qhov tob yog feem ntau ntawm 0.5 thiab 2mm, txheej txheem carburizing feem ntau tau teeb tsa ntawm ib nrab ua tiav thiab tiav.
Cov txheej txheem txheej txheem yog feem ntau: blanking-forging-normalizing-rough thiab semi-finishing-carburizing thiab quenching-finishing.
Thaum qhov tsis-carburized ntawm ib feem carburized ib feem tau txais txheej txheem txheej txheem ntawm kev tshem cov txheej txheej carburized ntau dhau tom qab nce cov npoo, cov txheej txheem tshem tawm cov txheej txheej carburized ntau yuav tsum tau npaj tom qab carburizing thiab ua ntej quenching.
(3) Kev kho mob Nitriding
Nitriding yog txheej txheem kev kho mob uas tso cai rau nitrogen atoms nkag mus rau hauv cov hlau kom tau txais txheej txheej ntawm nitrogen-muaj cov sib xyaw. Cov txheej nitriding tuaj yeem txhim kho qhov nyuaj, hnav tsis kam, qaug zog thiab tiv thaiv kev txhuam ntawm qhov chaw ntawm ntu. Vim tias qhov kev kho cua sov nitriding qis, qhov hloov pauv me me, thiab txheej txheej nitriding yog nyias (feem ntau tsis ntau tshaj 0.6 ~ 0.7mm), txheej txheem nitriding yuav tsum tau npaj kom deb li deb tau. Txhawm rau txo qhov deformation thaum lub sij hawm nitriding, nws feem ntau xav tau tom qab txiav. Ua kom muaj kev ntxhov siab-txo qhov kub thiab txias.
