Yuav muaj qhov tsis xws luag hauv txhua qhov casting.Lub hav zoov ntawm cov teeb meem no yuav ua rau muaj kev phom sij loj heev rau qhov zoo ntawm qhov casting.Kev kho vuam kom tshem tawm cov kev tsis zoo no hauv cov txheej txheem tsim khoom kuj yuav coj lub nra hnyav rau cov txheej txheem ntau lawm..Tshwj xeeb, raws li lub valve yog nyias-plhaub casting uas raug rau siab thiab kub, lub compactness ntawm nws sab hauv yog ib qho tseem ceeb heev.Yog li ntawd, qhov tsis xws luag sab hauv ntawm castings dhau los ua qhov kev txiav txim siab cuam tshuam rau qhov zoo ntawm castings.
Internal tsis xws luag ntawm valve castings mas muaj xws li pores, slag inclusions, shrinkage porosity thiab tawg.
Ntawm no yuav qhia txog ib qho ntawm qhov tsis xws luag - slag inclusions thiab tawg
(1) Xuab zeb suav nrog (slag):
Sand inclusion (slag), feem ntau hu ua trachoma, yog ib qho tsis sib xws los yog qhov tsis sib xws nyob rau sab hauv ntawm qhov casting.Lub qhov yog tov nrog molding xuab zeb los yog steel slag, thiab qhov loj yog tsis xwm yeem.Sib sau ua ke hauv ib lossis ntau qhov chaw, feem ntau nyob rau sab sauv.
Ua rau cov xuab zeb suav nrog (slag):
Slag suav nrog yog tsim los ntawm kev sib cais steel slag nkag mus rau hauv casting nrog cov hlau molten thaum lub sij hawm smelting los yog pouring txheej txheem ntawm molten hlau.Sand inclusion yog tshwm sim los ntawm tsis txaus compactness ntawm kab noj hniav thaum molding.Thaum molten hlau yog poured rau hauv kab noj hniav, molding xuab zeb yog ntxuav los ntawm cov hlau molten thiab nkag mus rau hauv lub casting.Tsis tas li ntawd, kev ua haujlwm tsis raug thaum kho thiab kaw lub thawv, thiab qhov tshwm sim ntawm cov xuab zeb poob kuj yog qhov ua rau cov xuab zeb suav nrog.
Cov txheej txheem los tiv thaiv cov xuab zeb suav nrog (slag):
①Thaum molten hlau yog smelted, tso pa thiab slag yuav tsum tau tas li kom huv si.Tom qab cov hlau molten tso tawm, nws yuav tsum tau calmed nyob rau hauv lub ladle, uas yog conducive rau lub floating ntawm lub steel slag.
② Lub hnab ntim ntawm cov hlau molten yuav tsum tsis txhob muab tig ntau li ntau tau, tab sis lub hnab ntim tshuaj yej lossis lub hnab ntim hauv qab, thiaj li tiv thaiv cov slag nyob rau sab sauv ntawm cov hlau molten los ntawm kev nkag mus rau hauv cov kab noj hniav nrog cov hlau molten. .
③ Casting slag ntsuas yuav tsum tau ua thaum cov hlau molten yog nchuav kom txo cov hlau slag nkag mus rau hauv kab noj hniav nrog cov hlau molten.
④ Txhawm rau txo qhov muaj peev xwm ntawm cov xuab zeb suav nrog, xyuas kom lub compactness ntawm cov xuab zeb pwm thaum molding, ceev faj tsis txhob poob cov xuab zeb thaum kho pwm, thiab tshuab pwm kab noj hniav kom huv si ua ntej kaw lub thawv.
(2) Kev tawg:
Feem ntau ntawm cov kab nrib pleb hauv castings yog kub tawg nrog cov duab tsis sib xws, nkag mus lossis tsis nkag mus, txuas ntxiv lossis cuam tshuam, thiab cov hlau ntawm qhov tawg yog tsaus lossis muaj oxidation nto.
Muaj ob qho laj thawj rau cov kab nrib pleb: qhov kub thiab txias siab thiab ua kua zaj duab xis deformation.
Kev kub ntxhov siab yog qhov kev ntxhov siab uas tsim los ntawm qhov shrinkage thiab deformation ntawm molten steel ntawm qhov kub thiab txias.Thaum qhov kev ntxhov siab dhau lub zog lossis cov yas deformation txwv ntawm cov hlau ntawm qhov kub no, cov kab nrib pleb yuav tshwm sim.Ua kua zaj duab xis deformation yog tsim cov kua zaj duab xis ntawm cov nplej ntawm molten steel thaum solidification thiab crystallization.Nrog rau kev nce qib ntawm solidification thiab crystallization, cov kua zaj duab xis yog deformed.Thaum tus nqi deformation thiab deformation ceev tshaj ib qho kev txwv, cov kab nrib pleb tshwm sim.Qhov kub ntawm qhov kub tawg yog li 1200-1450 ° C.
Yam uas ua rau tawg:
①S thiab P cov ntsiab lus hauv cov hlau yog cov teeb meem uas ua rau tawg.Lawv eutectic nrog hlau txo lub zog thiab plasticity ntawm cam khwb cia hlau ntawm qhov kub thiab txias, ua rau tawg.
② Cov slag suav nrog thiab kev sib cais hauv cov hlau ua rau muaj kev ntxhov siab ntau ntxiv, yog li ua rau muaj kev kub ntxhov.
③ Qhov ntau dua qhov linear shrinkage coefficient ntawm qib steel, ntau dua qhov nyiam ntawm thermal cracking.
④ Cov thermal conductivity ntau dua ntawm cov qib steel, qhov ntau dua qhov nro ntawm qhov chaw, qhov zoo dua qhov kub thiab txias, thiab qhov me me ntawm thermal cracking.
⑤ Cov qauv tsim ntawm cov casting tsis zoo nyob rau hauv manufacturability.Piv txwv li, lub fillet yog me me heev, lub phab ntsa thickness sib txawv yog loj heev, thiab lub siab concentration yog loj, uas yuav ua rau tawg.
⑥ Lub compactness ntawm cov xuab zeb pwm yog siab dhau lawm, thiab cov neeg pluag concession ntawm cov tub ntxhais hinders lub shrinkage ntawm lub casting thiab ua rau kom cov kev xav ntawm cov kab nrib pleb.
⑦ Lwm yam xws li kev npaj tsis raug ntawm cov dej ntws tawm, kev kub ceev ceev ntawm cov castings, kev ntxhov siab ntau dhau los ntawm kev txiav cov risers thiab kev kho cua sov yuav cuam tshuam rau tiam ntawm cov kab nrib pleb.
Raws li qhov ua rau thiab cuam tshuam ntawm cov kab nrib pleb saum toj no, cov kev ntsuas sib xws tuaj yeem raug coj los txo thiab zam qhov tshwm sim ntawm qhov tawg tsis xws luag.
Raws li kev soj ntsuam saum toj no ntawm cov laj thawj ntawm qhov tsis xws luag, nrhiav cov teeb meem uas twb muaj lawm, thiab siv cov kev txhim kho zoo sib xws, ib txoj hauv kev los daws cov teeb meem casting tuaj yeem pom, uas muaj txiaj ntsig zoo rau kev txhim kho qhov zoo ntawm casting.
Post lub sij hawm: Aug-11-2022