Vim li cas thiaj tsis tuaj yeem txo cov ntsiab lus oxygen txhim kho lub neej qaug zog ntawm cov kabmob hlau? Tom qab kev soj ntsuam, nws ntseeg tau tias yog vim li cas yog tias tom qab tus nqi ntawm oxide inclusions raug txo, cov sulfide ntau dhau los ua qhov tsis zoo cuam tshuam rau lub neej qaug zog ntawm cov hlau. Tsuas yog los ntawm kev txo cov ntsiab lus ntawm oxides thiab sulfides tib lub sijhawm, cov khoom siv tuaj yeem siv tau tag nrho thiab lub neej qaug zog ntawm cov kabmob hlau tuaj yeem txhim kho tau zoo.
Yam dab tsi yuav cuam tshuam rau lub neej qaug zog ntawm cov kabmob steel? Cov teeb meem saum toj no tau txheeb xyuas raws li hauv qab no:
1. Cov nyhuv ntawm nitrides rau lub neej qaug zog
Qee cov kws tshawb fawb tau taw qhia tias thaum nitrogen ntxiv rau cov hlau, qhov ntim feem ntawm nitrides txo qis. Qhov no yog vim qhov txo qis ntawm qhov nruab nrab qhov loj ntawm cov khoom siv hauv cov hlau. Kev txwv los ntawm kev siv tshuab, tseem muaj ntau qhov kev suav nrog cov khoom me me dua 0.2 in. suav. Nws yog qhov tseeb ntawm cov khoom me me nitride uas muaj kev cuam tshuam ncaj qha rau lub neej qaug zog ntawm cov kabmob steel. Ti yog ib qho ntawm cov khoom muaj zog tshaj plaws los tsim nitrides. Nws muaj qhov sib nqus me me thiab yooj yim rau ntab. Ib feem ntawm Ti tseem nyob hauv cov hlau los tsim ntau lub kaum sab xis. Xws li kev suav nrog yuav ua rau muaj kev ntxhov siab hauv zos thiab qaug zog tawg, yog li nws yog qhov tsim nyog los tswj qhov tshwm sim ntawm cov kev suav no.
Cov txiaj ntsig kev sim qhia tau hais tias cov ntsiab lus oxygen hauv cov hlau raug txo kom qis dua 20ppm, cov ntsiab lus nitrogen tau nce, qhov loj, hom thiab kev faib tawm ntawm cov khoom tsis yog xim hlau tuaj yeem txhim kho, thiab cov khoom ruaj khov tau txo qis. Txawm hais tias nitride hais nyob rau hauv cov hlau nce, cov hais me me heev thiab raug faib nyob rau hauv ib tug dispersed lub xeev ntawm lub grain ciam teb los yog nyob rau hauv lub grain, uas yuav ua tau ib tug haum zoo, yog li ntawd lub zog thiab toughness ntawm bearing steel yog zoo matched, thiab lub hardness thiab lub zog ntawm cov hlau yog loj heev. , tshwj xeeb tshaj yog kev txhim kho cov nyhuv ntawm kev sib cuag qaug zog lub neej yog lub hom phiaj.
2. Cov nyhuv ntawm oxides rau lub neej qaug zog
Cov ntsiab lus oxygen hauv cov hlau yog qhov tseem ceeb cuam tshuam rau cov khoom siv. Qhov qis dua cov ntsiab lus ntawm cov pa oxygen, qhov siab dua qhov purity thiab ntev dua qhov sib npaug ntawm lub neej. Muaj kev sib raug zoo ntawm cov ntsiab lus oxygen hauv cov hlau thiab oxides. Thaum lub sij hawm solidification txheej txheem ntawm molten steel, yaj cov pa oxygen ntawm txhuas, calcium, silicon thiab lwm yam ntaub ntawv oxides. Cov ntsiab lus oxide suav nrog yog kev ua haujlwm ntawm cov pa oxygen. Raws li cov ntsiab lus oxygen txo, cov oxide suav nrog yuav txo qis; cov ntsiab lus nitrogen yog tib yam li cov ntsiab lus oxygen, thiab kuj muaj kev sib raug zoo nrog cov nitride, tab sis vim hais tias cov oxide yog dispersed ntau nyob rau hauv cov hlau, nws plays tib lub luag hauj lwm raws li lub fulcrum ntawm cov carbide. , yog li nws tsis muaj kev puas tsuaj rau lub neej qaug zog ntawm cov hlau.
Vim tias muaj cov oxides, cov hlau rhuav tshem qhov txuas ntxiv ntawm cov hlau matrix, thiab vim tias qhov nthuav dav coefficient ntawm oxides me dua qhov nthuav coefficient ntawm cov kabmob steel matrix, thaum raug hloov kev ntxhov siab, nws yog ib qho yooj yim los tsim kev ntxhov siab thiab ua. keeb kwm ntawm hlau qaug zog. Feem ntau ntawm cov kev ntxhov siab concentration tshwm sim ntawm oxides, point inclusions thiab matrix. Thaum qhov kev ntxhov siab nce mus txog qhov loj txaus, cov kab nrib pleb yuav tshwm sim, uas yuav nthuav dav thiab ua kom puas. Qhov qis dua cov plasticity ntawm cov inclusions thiab cov duab sharper, qhov ntau dua qhov kev ntxhov siab concentration.
3. Cov nyhuv ntawm sulfide rau qaug zog lub neej
Yuav luag tag nrho cov ntsiab lus ntawm sulfur nyob rau hauv steel muaj nyob rau hauv daim ntawv ntawm sulfides. Qhov siab dua cov sulfur cov ntsiab lus hauv cov hlau, qhov siab dua cov sulfide hauv cov hlau. Txawm li cas los xij, vim hais tias cov sulfide tuaj yeem ua tau zoo nyob ib puag ncig los ntawm oxide, qhov cuam tshuam ntawm oxide ntawm lub neej qaug zog yog txo, yog li cov kev cuam tshuam ntawm tus naj npawb ntawm kev suav nrog rau lub neej qaug zog tsis yog kiag li, ntsig txog qhov xwm txheej, qhov loj me thiab kev faib tawm ntawm cov tshuaj sulfide. cov suav nrog. Qhov muaj qee qhov kev suav nrog, qhov qis dua lub neej qaug zog yuav tsum yog, thiab lwm yam cuam tshuam yuav tsum raug txiav txim siab. Nyob rau hauv bearing steel, sulfides yog dispersed thiab faib nyob rau hauv ib tug zoo zoo, thiab yog tov nrog oxide inclusions, uas yog nyuaj rau txheeb xyuas txawm los ntawm metallographic txoj kev. Cov kev sim tau lees paub tias raws li cov txheej txheem qub, kev nce qib ntawm Al muaj txiaj ntsig zoo ntawm kev txo qis oxides thiab sulfides. Qhov no yog vim Ca muaj peev xwm desulfurization muaj zog. Kev suav nrog tsis tshua muaj kev cuam tshuam rau lub zog, tab sis muaj kev phom sij ntau dua rau lub zog ntawm cov hlau, thiab qhov kev puas tsuaj yog nyob ntawm lub zog ntawm cov hlau.
Xiao Jimei, tus kws tshaj lij paub zoo, tau taw qhia tias kev suav nrog hauv cov hlau yog ib theem nkig, qhov siab dua qhov ntim feem, qhov qis dua qhov toughness; qhov loj qhov loj ntawm cov inclusions, qhov ceev lub toughness poob. Rau lub toughness ntawm cleavage puas, qhov me me ntawm cov inclusions thiab qhov me me qhov sib nrug ntawm cov inclusions, lub tougher tsis tsuas tsis txo, tab sis nce. Cleavage fracture tsis tshua muaj tshwm sim, yog li ua kom lub zog tawg tawg. Qee tus neeg tau ua qhov kev sim tshwj xeeb: ob pawg ntawm cov hlau A thiab B yog tib yam hlau, tab sis cov kev suav nrog hauv txhua qhov sib txawv.
Tom qab kev kho cua sov, ob pawg ntawm cov hlau A thiab B tau mus txog tib lub zog tensile ntawm 95 kg / mm ', thiab cov txiaj ntsig zoo ntawm cov hlau A thiab B yog tib yam. Nyob rau hauv cov nqe lus ntawm elongation thiab cheeb tsam txo, B steel yog me ntsis qis dua A steel yog tseem tsim nyog. Tom qab qhov kev sim qaug zog (rotational bending), nws pom tau tias: Cov hlau yog cov khoom siv lub neej ntev nrog rau kev qaug zog siab; B yog cov khoom siv lub neej luv luv nrog kev txwv tsis pub qaug zog. Thaum qhov kev ntxhov siab ntawm cov qauv hlau yog me ntsis siab dua qhov kev qaug zog ntawm cov hlau A, lub neej ntawm B steel tsuas yog 1/10 ntawm cov hlau A. Kev suav nrog hauv cov hlau A thiab B yog oxides. Nyob rau hauv cov nqe lus ntawm tag nrho cov nqi ntawm inclusions, lub purity ntawm steel A yog phem tshaj li ntawm cov hlau B, tab sis cov oxide hais ntawm steel A yog ntawm tib qhov loj thiab sib npaug; steel B muaj qee qhov loj-particle suav nrog, thiab kev faib khoom tsis sib xws. . Qhov no qhia tau hais tias Mr. Xiao Jimei qhov kev xav yog qhov tseeb.
Post lub sij hawm: Lub Xya hli ntuj-25-2022