Nyob rau hauv ib txwm muaj xwm txheej, qhov tseeb ntawm qhov ntev ntawm cov castings raug cuam tshuam los ntawm ntau yam xws li cov qauv casting, cov khoom siv casting, pwm ua, plhaub ua, ci, nchuav, thiab lwm yam. Txhua qhov chaw lossis kev ua haujlwm tsis tsim nyog ntawm txhua qhov txuas yuav hloov pauv qhov nrawm ntawm qhov casting. Qhov no ua rau muaj kev hloov pauv ntawm qhov tseeb ntawm cov castings los ntawm qhov yuav tsum tau ua. Cov hauv qab no yog cov yam uas tuaj yeem ua rau muaj qhov tsis zoo ntawm qhov tseeb ntawm cov castings:
(1) Qhov cuam tshuam ntawm cov qauv casting: a. Casting phab ntsa tuab, qhov nrawm shrinkage loj, phab ntsa casting nyias, qhov nrawm shrinkage me. b. Qhov nrawm shrinkage dawb yog loj, thiab qhov nrawm shrinkage cuam tshuam yog me.
(2) Qhov cuam tshuam ntawm cov khoom siv casting: a. Cov pa roj carbon ntau dua hauv cov khoom siv, qhov me dua qhov linear shrinkage rate, thiab qhov qis dua cov pa roj carbon, qhov ntau dua qhov linear shrinkage rate. b. Qhov casting shrinkage rate ntawm cov khoom siv feem ntau yog raws li nram no: casting shrinkage rate K=(LM-LJ)/LJ × 100%, LM yog qhov loj ntawm qhov cavity, thiab LJ yog qhov loj ntawm casting. K raug cuam tshuam los ntawm cov hauv qab no: pwm quav ciab K1, casting qauv K2, alloy hom K3, pouring kub K4.
(3) Qhov cuam tshuam ntawm kev ua pwm rau qhov nrawm ntawm cov castings: a. Qhov cuam tshuam ntawm qhov kub ntawm kev txhaj tshuaj ciab, qhov siab ntawm kev txhaj tshuaj ciab, thiab lub sijhawm tuav siab rau qhov loj me ntawm kev nqis peev yog qhov pom tseeb tshaj plaws hauv qhov kub ntawm kev txhaj tshuaj ciab, ua raws li qhov siab ntawm kev txhaj tshuaj ciab, thiab lub sijhawm tuav siab tau lees paub Tom qab kev nqis peev tau tsim, nws muaj qhov cuam tshuam me ntsis rau qhov loj me kawg ntawm kev nqis peev. b. Qhov nrawm ntawm kev txhaj tshuaj ciab (pwm) cov khoom siv yog li 0.9-1.1%. c. Thaum lub pwm nqis peev khaws cia, yuav muaj kev ntswj ntxiv, thiab nws tus nqi ntswj yog li 10% ntawm tag nrho cov ntswj, tab sis thaum khaws cia rau 12 teev, qhov loj me ntawm pwm nqis peev yeej ruaj khov. d. Qhov nrawm ntawm kev ntswj radial ntawm lub pwm ciab tsuas yog 30-40% ntawm qhov nrawm ntawm kev ntswj ntev. Qhov kub ntawm kev txhaj tshuaj ciab muaj qhov cuam tshuam ntau dua rau qhov nrawm ntawm kev ntswj dawb dua li qhov nrawm ntawm kev ntswj uas cuam tshuam (qhov kub zoo tshaj plaws ntawm kev txhaj tshuaj ciab yog 57-59 ℃, Qhov kub siab dua, qhov nrawm dua).
(4) Cov khoom siv ua plhaub: siv xuab zeb zircon, hmoov zircon, xuab zeb Shangdian thiab hmoov Shangdian. Vim lawv cov coefficient nthuav dav me me, tsuas yog 4.6 × 10-6 / ℃, lawv tuaj yeem raug tsis quav ntsej.
(5) Cov nyhuv ntawm lub plhaub ci: Vim tias qhov coefficient nthuav dav ntawm lub plhaub me me, thaum qhov kub ntawm lub plhaub yog 1150 ℃, nws tsuas yog 0.053%, yog li nws tuaj yeem tsis quav ntsej.
(6) Qhov cuam tshuam ntawm qhov kub thiab txias casting: qhov kub thiab txias casting siab dua, qhov nrawm dua qhov shrinkage, thiab qhov kub thiab txias casting qis dua, qhov nrawm me dua, yog li qhov kub thiab txias casting yuav tsum tsim nyog.
Lub sijhawm tshaj tawm: Kaum Ib Hlis-15-2021