Muaj ntau yam kev tsim khoom los tsim ib qhokev cai hlau ib feem. Txhua tus muaj nws tus kheej txheej ntawm qhov zoo thiab qhov tsis zoo. Qee yam tseem ceeb cuam tshuam rau kev xaiv cov txheej txheem suav nrog cov hauv qab no:
- Ntau yam ntawm cov khoom xav tau
- Kev tsim cov khoom siv hlau
- Yuav Tsum Tau Txais
- Hlau specification
- Qhov yuav tsum tau ua tiav
- Tus nqi cuab yeej
- Economics ntawm machining piv rau cov txheej txheem nqi
- Cov khoom xa tuaj
Casting
Cov txheej txheem casting yog nchuav los yog txhaj cov hlau molten rau hauv pwm uas muaj kab noj hniav nrog cov duab uas xav tau.castings. Cov txheej txheem hlau casting tuaj yeem raug cais los ntawm hom pwm lossis los ntawm lub siab siv los sau cov pwm nrog kua hlau. Yog hais tias los ntawm hom pwm, cov txheej txheem casting tuaj yeem muab faib ua xuab zeb casting, peev casting thiab hlau tuag casting; hos yog hais tias los ntawm lub siab siv los sau cov pwm, cov txheej txheem casting yuav muab faib ua lub ntiajteb txawj nqus casting, tsis tshua muaj siab casting thiab siab casting.
Cov ntsiab lus ntawm Casting
Casting yog txheej txheem solidification. Yog li ntawd, lub microstructure tuaj yeem raug kho kom zoo, xws li cov qauv nplej, theem hloov pauv thiab nag lossis daus. Txawm li cas los xij, qhov tsis xws luag xws li shrinkage porosity, kab nrib pleb thiab kev sib cais kuj tseem cuam tshuam nrog kev sib koom ua ke. Cov teeb meem no tuaj yeem ua rau qis dua cov khoom siv kho tshuab. Kev kho cua sov tom ntej yog feem ntau yuav tsum tau txo qis kev ntxhov siab thiab ua kom zoo rau cov khoom siv kho tshuab.
Qhov zoo ntawm Casting:
- Cov khoom loj thiab nyuaj hlau casting yog ib qho yooj yim.
- Tus nqi ntau lawm, tshwj xeeb los ntawm cov kab molding tsis siv neeg.
- Kev tsim qauv yooj yim yog muaj thiab tsim nyog dua.
- Ntau hom hlau muaj: grey hlau, ductile hlau, carbon hlau, hlau alloy,stainless hlau, aluminium alloy, tooj dag, bronze thiab zinc alloy.
Disadvantages ntawm Casting:
- Cov teeb meem hauv cov castings
-Shrinkage porosity
- Hlau projections
- Kev sib tsoo, kub tearing, txias kaw
- Oxide, ua pa
- Misruns, ntim tsis txaus
- Kev suav nrog
- Yuav tsum tau kaw cov txheej txheem tswj thiab tshuaj xyuas (porosity yuav tshwm sim)
Forging
Forging yog txheej txheem kev tsim khoom uas cov hlau zoo li cov yas deformation nyob rau hauv lub siab zoo rau hauv qhov chaw muaj zog. Raws li yog siv cov pwm forging, cov txheej txheem forging yog invided rau hauv qhib tuag forging thiab kaw tuag forging. Tab sis yog tias los ntawm qhov kub ntawm cov hlau forged thiab alloy ua ntej forging, cov txheej txheem forging yuav muab faib ua txias forging, sov forging thiab kub forging.
Fundamentals ntawm Forging
Forging los yog txias forming yog metalforming txheej txheem. Tsis muaj melting thiab thiaj li solidification koom nrog. Yas deformation ua rau muaj ntau qhov kev hloov pauv uas ua rau muaj kev ntxhov siab ntau dua. Qhov tseeb tiag, kev sib zog ua kom tawv nqaij yog vim muaj kev cuam tshuam ntawm kev cuam tshuam nrog lwm yam kev cuam tshuam thiab lwm yam teeb meem (xws li cov ciam teb nplej). Tib lub sijhawm, cov duab ntawm cov khoom siv lead ua (dendrites) hloov tom qab cov yas ua haujlwm ntawm cov hlau.
Qhov zoo ntawm Forging:
- Zoo Mechanical zog (yield zog, ductility, toughness)
- Kev ntseeg tau (siv rau qhov tseem ceeb)
- Tsis muaj kua hlau kho
Disadvantages ntawm Forging:
- Tuag tsis puv
- Tuag tsis ua hauj lwm
- Cov duab txwv thaum txiav undercuts los yog cored seem yuav tsum tau
- Tag nrho cov nqi feem ntau yog siab dua casting
- Ntau cov kauj ruam feem ntau xav tau
Peb tuaj yeem paub qhov txawv ntawm kev ua haujlwm kub los ntawm kev ua haujlwm txias. Kub ua hauj lwm yog ua los ntawm qhov kub ntawm recrystallization; txias-ua haujlwm yog ua hauv qab nws. Nyob rau hauv kub ua hauj lwm strain hardening thiab distorted grain qauv yog sai heev tshem tawm los ntawm tsim ntawm tshiab strain-free nplej raws li qhov tshwm sim ntawm recrystallization. Kev nrawm nrawm ntawm qhov kub ua haujlwm kub pab hauv homogenizing lub preform. Thawj porosity kuj tuaj yeem txo qis, nws thiaj li kho tau. Metallurgical phenomena xws li strain hardening thiab recrystallization yog ib qho tseem ceeb vim hais tias cov kev hloov nyob rau hauv cov qauv ua rau ib tug nce nyob rau hauv ductility thiab toughness nyob rau hauv lub xeev cam khwb cia.
Ib qho tseem ceeb uas yuav tsum nco ntsoov yog tias qhov zoo ntawm cov khoom siv thiab kev kho cua sov yuav yog qhov tseem ceeb tshaj qhov sib txawv ntawm casting thiab forging nyob rau hauv qee kis.
Post lub sij hawm: Feb-24-2021