2. Automotive bearing cov khoom thiab ua kom tiav
Nyob rau tam sim no, lub tsheb lag luam tau tsim ntawm lub teeb, xis, muaj zog, siab zog, compact qauv, ruaj khov, kev ua kom zoo thiab kev ntseeg siab. Tsis tas li ntawd, vim muaj kev nce qib ntawm cov khoom siv tswj hluav taws xob, lub tsheb tseem tab tom tsim ntawm kev coj ntawm kev siv hluav taws xob tsawg, yooj yim thiab yooj yim, kev lag luam muaj zog thiab lwm yam kev ua haujlwm, yog li cov kabmob yob, ua ib qho tseem ceeb ntawm kev txhawb nqa lub tsheb, yuav tsum yoog raws cov ncauj ke no.
Thaum lub sijhawm ua haujlwm ntawm kev muab cov kabmob tsheb, qhov chaw ntawm lub cev sib dhos thiab lub nplhaib sab saum toj yuav tsum tiv taus zoo siab, uas tuaj yeem mus txog 5000N / mm2 los ntawm kev xam. Thaum cov kabmob tau khiav, nws tsis yog tsuas yog yob tab sis kuj swb, uas yog qhov raug siab thiab hloov kev sib cuag, tab sis kuj cuam tshuam los ntawm lub zog centrifugal, raws li qhia hauv daim duab 6. Raws li cov ntaub ntawv sau, cov qauv tsis ua haujlwm loj. ntawm cov thev naus laus zis tau tev, pitting, adhesion, ntaus, pob txha lov, poob ntawm qhov raug, suab nrov nrov dhau ntawm tus qauv, thiab lwm yam, yog li ntawd, qhov kev ua tau cov kabmob steel muaj qhov yuav tsum ua hauv qab no: (1) siab huv. (2) cov pa oxygen tsawg. Siab hardness thiab hnav tsis kam. (4) zoo dim seem. (5) txaus compressive zog thiab deformation tsis kam. 6. Kev ua haujlwm zoo hauv tshuab.
Raws li ib qho ntawm cov tshwj xeeb tseem ceeb steel ntau yam, qhov zoo thiab ua haujlwm ntawm kev coj tus kheej hlau loj cuam tshuam cov xim hlau ntau ntawm ib lub teb chaws. Yog lawm, lub neej thiab kev ntseeg siab ntawm cov tsav tsheb muaj feem xyuam nrog kev tsim thawj zaug, kev tsim khoom, kev siv roj, kev teeb tsa thiab txij nkawm, tab sis cov ntaub ntawv raw yog qhov tseem ceeb.
Los ntawm, hauv pib cov kabmob sib dhos ntawm ntau lub ntsiab, ntxiv rau lub tawb los ntawm tus thawj stamping steel kom nrov rau cov khoom nylon PA66 + 30% GF (xws li kev txhaj tshuaj molding) thiab foob yog feem ntau siv cov khoom siv roj hmab (xws li ACM + SUS430 (SPCC), NBR), Tuam Tshoj' s nws pib cov menyuam thiab cov dav siv sab hauv thiab sab nraud yog li nrog wC = 0.95% ~ 1.05%, wCr = 1.40% ~ 1.65% ntawm cov pa roj carbon ntau chromium bearing steel, txhawm rau txhim kho lub hardenability kom tau raws li qhov xav tau ntawm ib feem hloov pauv, nce cov ntsiab lus ntawm Mo tuaj yeem txhim kho cov txheej txheem ntawm qhov muaj zog siab siab carbonium chromium bearing steel: Cr6, 100, 100 crmo xws li Lub Tebchaws Yelemees, Sweden SKF2, SKF3, 52100.3, 52100.4, hauv Tebchaws Asmeskas, Nyiv' s SUJ2, SUJ3, SUJ4, SUJ5 thiab lwm yam, siv rau martensitic tawv tawv, kuj tsim rau super tuab phab ntsa kabmob qhov chaw ntawm bainite hardening, cov tshuaj lom neeg muaj qhov sib txawv me ntsis ntawm lawv, raws li lub rooj sib piv 1, cov no tuaj yeem yog qhov sib txawv ntawm GCr15 hlau.
表 1 GCr15 与 100Cr6 成分 成分 （分数））%）%）
牌号 | C | Cr | Si | Mn | S | P | Mo | N | Cu | O |
GCr15 | 0.95～1.05 | 1.4～1.65 | 0.15～0.35 | 0.25～0.45 | 12ppm | 20ppm | ≤0.1 | ≤0.2 | ≤0.25 | 10ppm |
100Cr6 | 0.93～1.05 | 1.35～1.6 | 0.15～0.35 | 0.25～0.45 | 10ppm | 25ppm | ≤0.1 | ≤0.3 | ≤0.25 | 8ppm |
Txawm hais tias ntau yam yog ib leeg, nws tseem yog qhov kev xav tau zoo tshaj plaws ntawm cov qauv hlau (cov hlau tsis muaj steel, cov kabmob hlau, lub caij nplooj ntoos hlav steel, cov hlau tsis xeb, cov taub hau txias hlau). Nruj yog qhov yuav tsum txhim kho cov pa huv hlau kom nruj me ntsis O, S, Ca, N, Ti thiab lwm yam kab kawm cov ntsiab lus, kuj yuav tsum tswj kev smelting, casting, yob, forging thiab lwm cov txheej txheem hlau tuaj yeem ua rau muaj qhov tsis xws luag, xws li nqus degassing, electroslag remelting, ua kom zoo nkauj taws ua kom sov. Nws yog qhov tsis tseem ceeb ntawm qhov tseeb uas txo cov ntsiab lus oxygen yuav ua rau lub neej ntev kev nkees nkees ntawm cov kabmob hauv kev lag luam. LIG. 7 qhia cov nkhaus sib txheeb ntawm cov pa oxygen thiab txheeb ze lub neej ntawm cov kabmob. Hauv GB / T 18254 - 2002, O cov ntsiab lus ntawm cov pa roj carbon siab chromium bearing steel tau hais meej: tuag nrum steel ≤15ppm, nruam cov hlau ≤12ppm, nyob rau hauv ntau lawm tiag tiag, nrog kev txhim kho ntawm cov khoom siv hlau thiab cov txheej txheem ntau dua kev tswj hwm, Qib qis yuav ncav cuag 5ppm. Ntxiv rau, cov txheej txheem kev cog lus lossis kev pom zoo rau cov txheej txheem smelting, tsis suav cov xim hlau, cais tawm, txiav cov txheej pov tseg, macrostructure, microstructure, carbide inhomogeneity, qhov zoo tshaj plaws thiab dimension kam rau ua kev txwv yog kev koom tes, xws li steel mills thiab cov khoom lag luam ntau lawm hauv cov steel Hoobkas, yuav tsum nruj soj ntsuam thiab kev tswjhwm nruj, yuav tsum tsis txhob saib xyuas.
Yuav tsum tau ntxiv, nws pib tus kabmob dhau ntawm feem ntau ntawm cov kabmob yob, tsuas yog cov crankshaft bearing, txuas cov pas nrig, piston bushing, poob siab absorber nrog kev taw qhia, gearbox rov qab iav bushing, thiab lwm yam ntxiv rau cov kabmob zawv zawg, lawv tsis txhob' t koom nrog kev kub kev kho, kev cia siab rau cov hmoov metallurgy sintering + dov sib sau, cov khoom siv yog feem ntau ntawm wC 0.15% lossis tsawg dua kev lag luam steel (xws li, 08 Al), ntxaiv watts rau alloy txheej (xws li Al - Sn20Cu lossis hom tin, txhuas, tooj liab lossis txhuas coj cov khoom sib txawv). Qhov kev kho cua sov tau tham tom qab kuj yog rau lub tsheb yob cov kabmob.
3. Kev siv cua sov kho tshuab ntawm tsheb nqa tau
Lub luag haujlwm tseem ceeb ntawm cov khoom siv sib xyaw ua ke chromium hauv kev tsim kho cov kabmob steel yog txhawm rau txhim kho lub zog ntawm cov hlau, kom cov ntu hauv quenching, tempering ntawm ntu tag nrho kom tau ntau cov qauv tsis sib xws. Chromium tuaj yeem tsim cov hlau cementite (Fe, Cr) 3 c, austenitic lis cov roj, thaum rhaub kom txo cov steel overheating rhiab heev, txhim kho qhov hnav tsis kam, thiab tuaj yeem ua rau cov steel quenching thaum tau zoo acicular lossis cryptocrystalline martensite, nce ntawm lub hauv paus ntawm siab lub zog steel toughness, feem ntau tsis tas yuav cryogenic kev kho mob ntawm nws tus kheej cov kabmob, tshwj tsis yog tias qhov seem loj stability thiab cov ntsiab lus ntawm residual austenite muaj qhov tshwj xeeb.
(1) cov txheej txheem ntau lawm kev ntawm cov tsheb nqa cov seem
Cov kev tsim tawm dav dav ntawm steel pob ntxuag lub cev yog: bar khoom → pob billet kub tho sib sau → pob (cov ntaub ntawv) → mos sib tsoo treatment kho cua sov → nyuaj sib tsoo → zoo sib tsoo → zoo sib tsoo → zoo sib tsoo (polishing).
Cov txheej txheem tsim tawm dav hauv cov nplhaib sab hauv thiab sab nraud yog: cov khoom siv yeeb nkab (txias txias) → ua kom zoo, → tig → mos sib tsoo → kho kom sov → kho kub → sib tsoo → tiav.
Txoj kev ua haujlwm dav dav ntawm lub tawb yog: cov tawb zoo (nylon): dawb paug → tig → kos duab, kos qhov rai → kho qhov.
Lub tsev stamping (hlau): cov khoom txaij lossis cov ntaub ntawv → tsim, txiav txiav → hauv qab qhov rais → qhov cuam tshuam → siab nqes hav → nthuav dav → nthuav dav treatment
Cov kabmob nws pib, lub nplhaib sab nraud, sab hauv lub nplhaib sib dhos lub cev, lub log hub cov kabmob ob lossis peb tiam ntawm lub flange yuav tsum muaj kev kho kom raug cua sov, txhawm rau muab kev ua si tag nrho rau lub peev xwm ntawm cov khoom siv nws tus kheej, kom tau txais cov kev cia siab ua haujlwm thiab txhim kho lub neej kev pabcuam. ntawm cov khoom sib dhos ua ke, feem ntau suav nrog kev hais lus spheroidizing annealing, quenching + npau taws ntawm qhov kub tsawg, kev kho tshuaj cua sov, kev kho cua sov induction thiab lwm yam.
(2) kho cov cua sov ntawm cov txheej txheem tseem ceeb ntawm cov tsheb
Hauv qab no yog cov lus qhia luv luv ntawm cov cuab yeej siv kho cua sov, cov txheej txheem piv txwv, kev xav tau ntawm cov txuj ci, thiab kev kwv yees kev tsim kho.
Spheroidal annealing cov khoom siv feem ntau yog siv qhov cub hluav taws xob tiv thaiv ua kom cov nplaim hluav taws xob tsis zoo, tsis muaj oxidation, thiab tuaj yeem txhim kho cov khoom siv ntawm cov khoom seem. Qhov kub ntawm cov khoom kub cov kabmob yog 835 ~ 850 ℃, thiab ntsuas kub spherification yog 750 ~ 760 ℃, raws li qhia hauv FIG. 8. 8.
Tom qab lub pob yob lub cev tau raug tsim tawm, lub nruam nitrogen puag tiv thaiv kev tiv thaiv huab cua annealing rauv taws nrog aixielin roller hauv qab yog siv, raws li qhia hauv FIG. 9a. Spheroidal annealing kub yog 760 ℃, cov pa oxygen muaj peev xwm ,900, lwg taw tes ≤20 ℃, dej ntws nrawm qis 0.18 ± 0.02m3 / h, cua sov siab 150 ~ 300MPa, lub zog tawv ≤210HBW, decarburization txheej tsawg dua lossis sib npaug ntawm 0.25mm, mesh carbide ≤CN4.2, lub zog tawv ntawm cov pob steel tom qab tag nrho quenching thiab tempering yuav tsum ntawm 60HRC saum toj no.
Quenching thiab tempering cov cuab yeej siv feem ntau kuj siv kev tiv thaiv ib puag ncig cua sov, xws li cov saw hlau rauv taws, lub tog raj cua sov lossis lub laub-taws ua kom sov, li pom hauv FIG. 9b, nrog kev ua haujlwm siab ntau lawm thiab kev siv zog tsawg. Cov kev lag luam hauv nruab nrog suav nrog jiangsu fengdong, sab qaum teb kev lag luam, hangzhou jinzhou thiab lwm yam.
Siv rau sab hauv thiab sab nraud kev tiv thaiv cua sov ua kom sov tsis tu ncua, txuas ntxiv kom txo qhov deformation, siv KR468G tshwj xeeb roj quenching roj thiab kho cov cua kub xws li kub, lub sijhawm, ceev ntawm conveyor txoj siv khiav lossis tseem tuaj yeem siv rau hauv martensite gradation ntawm ntsev da dej quenching thiab cov txheej txheem nkhaus yog muaj nyob hauv daim duab 10, 63 ~ 64.5 HRC hardness tom qab quenching, tom qab 180 ntxiv lossis rho tawm 10 ℃ tempering hardness 61 ~ 63 HRC, kos rau taper nplhaib ib ncig ntawm 0.05 hli, 0.15 hli lossis tsawg dua ntawm cylindricity.
Qhov thib ob thiab thib peb tiam ntawm tsheb hub bearings yog nruab nrog flanges. Cov khoom siv yog S55C, thiab qhov saum npoo tawv ntawm thaj chaw quenched yuav tsum mus txog ntau dua 60HRC. Nws raug nquahu kom siv automatic induction quenching ntau lawm kab, zoo li hauv FIG. 9c. Qhov nruab nrab txias txias yog dej-raws quenching tov nrog kho cov teeb meem. Lub zog ntawm cov tshuaj quenching yog 0.2-0.6mpa.
Quenching thiab tempering cov cuab yeej siv feem ntau kuj siv kev tiv thaiv ib puag ncig cua sov, xws li cov saw hlau rauv taws, lub tog raj cua sov lossis lub laub-taws ua kom sov, li pom hauv FIG. 9b, nrog kev ua haujlwm siab ntau lawm thiab kev siv zog tsawg. Cov kev lag luam hauv nruab nrog suav nrog jiangsu fengdong, sab qaum teb kev lag luam, hangzhou jinzhou thiab lwm yam.
Siv rau sab hauv thiab sab nraud kev tiv thaiv cua sov ua kom sov tsis tu ncua, txuas ntxiv kom txo qhov deformation, siv KR468G tshwj xeeb roj quenching roj thiab kho cov cua kub xws li kub, lub sijhawm, ceev ntawm conveyor txoj siv khiav lossis tseem tuaj yeem siv rau hauv martensite gradation ntawm ntsev da dej quenching thiab cov txheej txheem nkhaus yog muaj nyob hauv daim duab 10, 63 ~ 64.5 HRC hardness tom qab quenching, tom qab 180 ntxiv lossis rho tawm 10 ℃ tempering hardness 61 ~ 63 HRC, kos rau taper nplhaib ib ncig ntawm 0.05 hli, 0.15 hli lossis tsawg dua ntawm cylindricity.
Qhov thib ob thiab thib peb tiam ntawm tsheb hub bearings yog nruab nrog flanges. Cov khoom siv yog S55C, thiab qhov saum npoo tawv ntawm thaj chaw quenched yuav tsum mus txog ntau dua 60HRC. Nws raug nquahu kom siv automatic induction quenching ntau lawm kab, zoo li hauv FIG. 9c. Qhov nruab nrab txias txias yog dej-raws quenching tov nrog kho cov teeb meem. Lub zog ntawm cov tshuaj quenching yog 0.2-0.6mpa.
Nrog cov kev txhim kho tas mus li ntawm cov cuab yeej siv kho cua sov hauv tsev thiab cov cuab yeej siv tshuab ntau lawm, daim ntawv thov hauv kev tsim thiab kev ua tiav ntawm cov khoom siv roj tsheb tau tau dhau los ua neeg paub tab. Lub thawv qub lub thawv cua sov, lub tshuab ua kom sov sov zoo nkauj, ntsev da dej ua kom sov, lub tshuab ua kom sov, cov cua kub cua sov thiab lwm yam khoom siv tau yooj yim tshem tawm, tam sim no ntau ntawm cov neeg nyiam yog cov khoom siv tiv thaiv huab cua pab los ntawm siab viav vias adsorption, zaj duab xis nitrogen ntau lawm thiab lwm yam thev naus laus zis , nrog rau cov menyuam cov menyuam siv hlua taws ua kom sov raws li qhov hluav taws xob ntawm tag nrho quench xa kab thiab tsis siv neeg induction quenching rov kab tau dhau los ua qhov tseem ceeb. Ib qho ntxiv, kev hloov pauv ntawm kev tiv thaiv ib puag ncig mus rau cov huab cua tswj tau tau thiab lub cua sov tswj lub tshuab los ntawm cov hlau xov tooj ib leeg rau pawg tswj hwm computer yuav maj mam dhau los ua ob txoj kev loj.