Lub hom phiaj ntawm kev kho cua sov yog txhawm rau txhim kho cov khoom siv hluav taws xob ntawm cov kav dej steel thiab cov kav dej precision steel, tshem tawm cov kev ntxhov siab seem, thiab txhim kho machinability ntawm steel hlau. Nyob ntawm cov hom phiaj tshwj xeeb, cov txheej txheem kho cua sov tuaj yeem muab faib ua ob pawg: kev npaj kho cua sov thiab kev kho cua sov zaum kawg.
Kev npaj kho cua sov
Lub hom phiaj ntawm kev npaj kho cua sov yog txhawm rau txhim kho kev ua haujlwm, tshem tawm cov kev ntxhov siab sab hauv, thiab npaj cov qauv hlau zoo rau kev kho cua sov zaum kawg. Cov txheej txheem muaj xws li annealing, normalizing, laus, thiab quenching thiab tempering.
(1) Annealing thiab normalizing
Annealing thiab normalizing yog siv rau kub-ua hauj lwm blanks. Carbon steels thiab alloy steels uas muaj cov ntsiab lus carbon ntau dua 0.5% feem ntau yog annealed los txo lawv hardness thiab pab txiav. Hloov pauv, cov uas muaj cov ntsiab lus carbon hauv qab 0.5% tau ua kom zoo li qub kom tsis txhob muaj qhov muag ntau dhau uas tuaj yeem ua rau cov cuab yeej ua rau lub sijhawm txiav. Annealing thiab normalizing kuj ua kom zoo cov qauv nplej, homogenize microstructures, thiab npaj cov khoom siv rau kev kho cua sov tom ntej. Cov txheej txheem no feem ntau ua tom qab kev tsim khoom tsis muaj thiab ua ntej machining ntxhib.
(2) Kev laus kev kho mob
Kev laus kev kho mob feem ntau yog siv los tshem tawm cov kev ntxhov siab sab hauv tsim thaum lub sijhawm tsim khoom thiab machining. Rau cov khoom uas xav tau kev ua kom zoo, ib qho kev laus ib leeg ua ntej ua tiav kom tsis txhob muaj kev thauj mus los ntau dhau. Txawm li cas los xij, rau qhov chaw uas yuav tsum tau ua kom siab dua (xws li lub thawv ntawm lub tshuab tho txawv), ob lossis ntau dua kev kho mob yuav tsim nyog. Tej yam yooj yim feem ntau tsis tas yuav kho kev laus.
Sib nrug los ntawm castings, precision qhov chaw nrog tsis zoo rigidity (piv txwv li, precision txhuas screws) feem ntau undergo ntau yam kev laus kev kho mob ntawm ntxhib thiab semi-tiav machining kom tshem tawm cov kev ntxhov siab nyob rau hauv thiab stabilize kev ua kom raug. Qee qhov chaw axial kuj xav tau kev kho mob laus tom qab straightening.
(3) quenching thiab tempering
quenching thiab tempering yuav quenching tom qab high-temperature tempering. Cov txheej txheem no yields ib tug uniform thiab nplua-grained tempered sorbite qauv, npaj cov khoom rau txo deformation thaum lub sij hawm tom ntej nto quenching thiab nitriding. Yog li, quenching thiab tempering kuj tseem tuaj yeem ua kev npaj kho cua sov.
Vim nws cov khoom siv zoo heev, quenching thiab tempering kuj tuaj yeem siv los ua kev kho cua sov zaum kawg rau cov khoom uas xav tau me ntsis rau hardness thiab hnav tsis kam.
Kev kho cua sov kawg
Lub hom phiaj ntawm kev kho cua sov zaum kawg yog los txhim kho cov khoom siv kho tshuab xws li hardness, hnav tsis kam, thiab lub zog.
(1) Quenching
quenching tuaj yeem yog nto quenching lossis los ntawm quenching. Deg quenching yog dav siv vim tsawg deformation, oxidation, thiab decarburization. Nws muaj lub zog sab nraud, zoo hnav tsis kam, thiab tswj tau zoo sab hauv toughness thiab cuam tshuam tsis kam. Txhawm rau txhim kho cov khoom siv hluav taws xob ntawm qhov chaw-quenched, kev npaj kho cua sov zoo li quenching thiab tempering lossis normalizing feem ntau ua ntej ua ntej. Cov txheej txheem raug yog: txiav → forging → normalizing (los yog annealing) → ntxhib machining → quenching thiab tempering → semi-tiav machining → nto quenching → tiav machining.
(2) Carburizing thiab quenching
Carburizing thiab quenching yog tsim rau cov pa roj carbon tsawg thiab cov hlau tsis tshua muaj hlau. Cov txheej txheem no ua rau cov pa roj carbon ntsiab lus ntawm qhov chaw ntawm qhov chaw, uas ua rau lub siab tawv tom qab quenching, thaum lub hauv paus tseem muaj zog nruab nrab, siab toughness, thiab plasticity. Carburizing tuaj yeem yog tag nrho lossis ib nrab, nrog rau yav tom ntej yuav tsum tau ntsuas los tiv thaiv carburizing (piv txwv li, tooj liab plating lossis anti-carburizing txheej) rau cov cheeb tsam uas tsis yog carburized. Vim yog qhov tseem ceeb deformation thiab carburizing qhov tob feem ntau ntawm 0.5 thiab 2mm, cov txheej txheem carburizing feem ntau yog teem sijhawm ntawm semi-tiav thiab tiav machining.
Cov txheej txheem raug yog: txiav → forging → normalizing → ntxhib thiab semi-tiav machining → carburizing thiab quenching → tiav machining.
Thaum qhov tsis-carburized feem ntawm ib feem ntawm cov carburized yog loj kom tso cai rau tshem tawm cov txheej carburized ntau dhau, qhov kev tshem tawm no yuav tsum tshwm sim tom qab carburizing tab sis ua ntej quenching.
(3) Nitriding
Nitriding yuav infiltrating nitrogen atoms rau hauv cov hlau nto los tsim ib txheej ntawm nitrogen tebchaw. Cov txheej nitrided txhim kho qhov nyuaj ntawm qhov chaw, hnav tsis kam, qaug zog, thiab corrosion kuj. Txij li thaum nitriding ua haujlwm ntawm qhov kub thiab txias nrog tsawg deformation thiab tsim ib txheej nyias (feem ntau tsis ntau tshaj 0.6-0.7mm), cov txheej txheem nitriding yuav tsum tau teem caij lig li sai tau. Txhawm rau txo qis deformation thaum lub sij hawm nitriding, kev ntxhov siab-relieving high-temperature tempering yog feem ntau ua tom qab txiav.
