Lub peev xwm los tiv thaiv kev puas tsuaj thiab tiv thaiv indentation yog ob yam tseem ceeb ntawm qee yam hlau.Thaum xaiv ib hom hlau, ib qho tseem ceeb uas yuav tsum tau coj mus rau hauv tus account yog nws hardness, uas yog ntsuas ntawm cov khoom. Qhov chaw sab nrauv ntawm cov hlau yog qhov tseem ceeb tshaj plaws los txiav txim siab qhov zoo tagnrho hardness rau. Qhov no yog vim qhov tseeb tias nws yog qhov chaw uas tau txais ncaj qha ntaus thiab abraded tshaj plaws. Qee cov hlau tau dhau los ua cov txheej txheem hu ua case hardening los hloov lawv qhov hardness kom ntseeg tau tias hardness ntawm cov hlau substrate yog tsim nyog.
Case Hardening yog dab tsi?
Case hardening yog txheej txheem kev kho cua sov uas ua kom tawv tawv ntawm cov hlau substrate thaum tuav cov tub ntxhais softer. Qhov no tso cai rau muab cov khoom zoo tshaj plaws ntawm cov hlau mos thiab tawv rau hauv ib feem.
Piv nrog rau cov khoom siv tawv, cov khoom muag muag tuaj yeem tiv taus qhov cuam tshuam zoo dua. Tsis tas li ntawd, nws muaj zog dua, muaj zog dua, thiab tawv dua, tab sis nws cov hnav tsis kam yog tsis txaus. Txhawm rau kom paub tseeb tias cov khoom tsis hnav tawm ntawm kev puas tsuaj lossis kev sib txhuam, kev hnav zoo yog qhov tseem ceeb. Peb tuaj yeem txo cov khoom hnav zoo heev yam tsis muaj kev txi lwm yam zoo los ntawm kev ua kom tawv nqaij sab nrauv xwb.
Ib txheej nyias, tawv tawv tuaj yeem tau txais ntau txoj hauv kev, suav nrog los ntawm kev ntxiv cov khoom ntxiv rau saum npoo los yog hloov cov qauv siv lead ua. Tab sis qhov kub thiab txias yog yuav luag ib txwm xav tau rau cov ntaub ntawv hardening, tsis hais hom twg.
Vim li cas Case Harden?
Muaj ob peb lub laj thawj los ua kom cov khoom tawv tawv dua li sim ua kom tawv tawv tag nrho cov khoom hlau. Ib qho laj thawj yog kev ua haujlwm zoo. Tsawg zog thiab tsawg lub sij hawm yuav tsum tau ua kom sov lub sab nrauv ntawm ib tug hlau uas tsis yog nws tag nrho cov seem. Cov kev ua tau zoo no tuaj yeem ua rau muaj kev txuag nyiaj ntau hauv kev tsim khoom loj. Lwm qhov laj thawj vim li cas cov ntaub ntawv tawv tawv tau siv dav yog vim kev ua haujlwm. Nws tuaj yeem muaj txiaj ntsig zoo kom muaj cov hlau nrog lub plhaub tawv sab nraud thiab cov khoom siv sab hauv ntau dua. Ib qho piv txwv ntawm qhov no yuav yog thaum cov hlau xav tau los tiv thaiv kev puas tsuaj, tab sis tseem yuav tsum muaj peev xwm nqus tau qhov cuam tshuam yam tsis ua rau muaj kev puas tsuaj tag nrho.
Types ntawm Case Hardening Methods
Lub hauv paus ntsiab lus ntawm rooj plaub hardening yog qhov yooj yim heev. Peb xav kom lub nto los ua ib tug nyuaj qauv hu ua martensite. Tab sis cov qauv no tsuas yog thaum cov khoom siv hlau raug quenched ntawm qhov kub thiab txias thiab muab cov ntsiab lus carbon ntawm steel alloy siab txaus.
Yog tias cov ntsiab lus carbon txaus, peb tsuas yog yuav tsum tau cua sov thiab quench qhov. Tab sis yog tias cov ntsiab lus carbon tsawg lossis yog tias peb xav tau qhov nyuaj, cov ntsiab lus xws li carbon thiab nitrogen yuav tsum tau ntxiv rau cov khoom siv saum npoo. Tam sim no cia peb saib cov txheej txheem sib txawv siv los ua kom tiav cov ntaub ntawv hardening raws li cov ntsiab lus saum toj no.
Cua sov thiab quenching
Kev lig kev cai, cua sov thiab quenching tau siv los ua kom tawv tawv hauv ntau yam hlau. Ib txoj hauv kev ntawm rooj plaub-hardening hlau yog siv cov nplaim hluav taws xob ncaj qha rau cov hlau. Kev siv cov cua kub inductive tshwm sim qee zaus. Cov hlau ntu qhov kub thiab txias tau nce sai hauv ob qho xwm txheej. Yog li ntawd, austenite siv lead ua qauv hloov pearlite siv lead ua qauv.
Thaum lub teeb kub tau mus txog, ib feem yog txias sai heev, feem ntau yog muab tso rau hauv dej. Qhov no hloov cov qauv siv lead ua ib zaug ntxiv, lub sij hawm no los ntawm austenite mus rau martensite uas yog ib qho nyuaj heev.
Txij li thaum tsuas yog qhov saum npoo tau hloov pauv hauv cov qauv siv lead ua, qhov nyuaj tsuas yog nyob ntawm qhov chaw. Tab sis nyob rau hauv thiaj li yuav tau txais txiaj ntsig los ntawm txoj kev no, yuav tsum muaj cov pa roj carbon txaus hauv cov khoom qub. Nyob rau hauv cov ntaub ntawv ntawm tsawg carbon cov ntsiab lus (<0.3%) in the metal part, this method will not yield favourable results.
Carburising
Yog tias cov pa roj carbon ntau qis dua 0.3%, peb yuav tsum ntxiv cov pa roj carbon ntau ntxiv rau qhov ua ntej nws ua rau cua sov + quenching. Muab ib feem los ntawm cov txheej txheem carburising yog ib txoj hauv kev ua li ntawd.
Carburizing suav nrog cua sov cov khoom siv hlau rau lub sijhawm ua ntej thaum muaj cov pa roj carbon monoxide sab nraud. Cov pa roj carbon monoxide los ntawm cov khoom carbonaceous diffuses rau hauv cov hlau thaum kub kub. Cov cua kub ntau dua thiab lub sij hawm cua sov ntev ua rau cov pa roj carbon absorbed rau hauv cov hlau ntau dua.
Thaum carburising nce cov ntsiab lus ntawm cov hlau txheej txheej, peb muab nws los ntawm nplaim taws hardening los yog induction hardening kom cov hardness.
Nitriding
Rau cov hlau alloy uas muaj cov khoom xws li txhuas, chromium thiab molybdenum, peb tuaj yeem siv nitriding rau cov ntaub ntawv hardening.
Ib feem yog rhuab nyob rau hauv lub xub ntiag ntawm nitrogen gas thiab dissociated ammonia los ua nitrides. Cov nitrides kuj nce hardness ntawm cov khoom.
Txij li thaum cov khoom yog rhuab mus rau 620 degree (1150 degree F), nitriding feem ntau tshwm sim ntawm qis kub. Lub diffusion thiab ua kom tawv tawv yuav tob dua qhov ntev nws khaws cia ntawm qhov kub thiab txias.
Dab tsi ntawm cov hlau tuaj yeem ua Case Hardened?
Cov hlau uas tuaj yeem ua kom tawv nqaij feem ntau txwv rau cov ntaub ntawv ferrous, txawm hais tias muaj cov xwm txheej tshwj xeeb xws li nitriding ntawm qee cov titanium lossis aluminium alloys. Cov ferrous hlau feem ntau cov ntaub ntawv hardened yog:
Tsawg carbon steel
High carbon hlau
Cam khwb cia hlau
Siab zog qis alloy steel
Cov cuab yeej steel
Stainless hlau
Qee cov khoom sib xws uas cov ntaub ntawv hardened muaj xws li:
Gears
Fasteners
Camshafts
Qws
Pins
