Yog vim li cas Bearing Steel Xav Tau Forging thiab Preparatory Heat Treatment
Siab - carbon chromium bearing steel xws li GCr15, npog los ntawm GB / T 18254 hauv Suav teb thiab los ntawm lub pob thiab cov menyuam bearing steel seem ntawm EN ISO 683-17 thoob ntiaj teb, yog alloyed heev thiab hardens mus rau ib tug heev hardness. Qhov kev sib xyaw ua ke no kuj ua rau cov qauv nrum ntxhib thiab tshuaj sib cais, nrog cov carbides concentrated hauv bands thiab ntawm cov ciam teb.
Forging rhuav tshem cov qauv cam khwb cia thiab kaw cov porosity sab hauv, thiab kev npaj kho cua sov uas ua raws li coj cov hlau mus rau qhov muag muag, machinable thiab structurally uniform mob ua ntej lub nplhaib tig thiab thaum kawg hardened. Hla lossis shortening cov kauj ruam no tshwm sim tom qab yog distortion, tawg lossis luv luv lub neej.
Los ntawm Ingot mus rau Billet: Cropping thiab Diffusion Annealing
Txoj kev pib nrog ingot casting. Sab saum toj ntawm lub ingot, uas muaj cov yeeb nkab shrinkage thiab qhov hnyav tshaj qhov sib cais, raug txiav tawm kom cov khoom puas tsis nkag mus rau hauv cov khoom. Cov kauj ruam kev cog qoob loo no yog qhov txiav txim siab rau kev coj tus kheej zoo, vim tias kev suav nrog thiab cov porosity concentrated hauv lub hau pov tseg tsis tuaj yeem raug tshem tawm los ntawm cov txheej txheem tom qab.
Cov qoob loo qoob loo yog tom qab ntawd muab qhov sib txawv ntawm qhov sib txawv, qhov ntev siab -kub tsau uas cia cov ntsiab lus alloying thiab cov pa roj rov faib los ntawm ntu. Diffusion annealing txo cov macrosegregation tau txais los ntawm casting thiab softens lub ingot txaus rau thawj forging lag luam. Nws yog ib qho qeeb, lub zog- kev kho mob hnyav, tab sis nws ua rau cov qauv pib sib txawv ntau dua li cov hlau uas tau muab los ntawm cov hlau tsis tu ncua.
Forging Practice thiab Carbide Segregation
Forging yog ua nyob rau hauv theem. Lub ingot yog thawj zaug chim thiab ua hauj lwm rau hauv ib lub polyhedron kom deformation ua nyob rau hauv ob peb cov lus qhia, uas lov lub dendritic network thiab disperses cov banded carbides. Lub qhov khoob yog ces forged mus rau qhov yuav tsum tau bar los yog nplhaib seem nrog ib tug tswj forging piv thiaj li hais tias lub deformation mus txog qhov chaw ntawm seem.
Kev tswj qhov kub thiab txias yog qhov tseem ceeb. Thawj qhov kub forging yuav tsum tsis txhob siab dhau, vim overheating coarsens lub austenite grain thiab tuaj yeem ua rau kub hnyiab ntawm cov ciam teb; nws yuav tsum tsis txhob yuav tsawg heev uas cov hlau ua hauj lwm nyob rau hauv ib tug nkig ntau yam. Tom qab qhov kawg forging hla lub qhov khoob yog txias rau hauv txoj kev tswj hwm, siv cov cua txias los yog cov tshuaj tsuag kom txias, kom cov carbide tes hauj lwm tsis ua rau cov av ua ntej austenite grain ciam teb.
Cov kabmob feem ntau yog tsim los ntawm txoj kev forging es tsis yog los ntawm qhov yooj yim nruam casting vim cov forged dawb paug muaj ib tug sounder thawj qauv thiab ib tug ntau yam carbide tis, uas yog ib qho tseem ceeb rau dov kev tiv thaiv qaug zog.
Spheroidize Annealing thiab Network Carbide Control
Tom qab forging thiab blanking, cov khoom yog spheroidize annealed. Cov kev kho mob tuav cov hlau hauv qab qhov ntsuas kub tseem ceeb rau lub sijhawm ntev thiab tom qab ntawd txias nws maj mam, hloov cov lamellar carbide rau hauv cov globules me me dispersed hauv ferritic matrix. Qhov tshwm sim yog ib tug mos mos, machinable qauv nrog ib tug txawm carbide tis thiab ib tug hardness tsawg txaus rau tig, thiab nws kuj npaj cov qauv kom qhov kawg hardening kev kho mob muab ib tug zoo, uniform martensite.
Spheroidize annealing yog siv nyob rau hauv ntau cov ntaub ntawv rau tuav, daim hlau los yog blocks, hlau thiab yeeb nkab, thiab dov rings, vim hais tias cov seem thiab lub hom phiaj kev ua hauj lwm txawv. Qhov twg forging los yog txias tau tawm hauv lub network ntawm carbides nyob rau hauv cov ciam teb ntawm grain, ib tug normalizing kev kho mob yog siv los rhuav lub network ua ntej spheroidize annealing, vim hais tias ib tug unbroken network yog ib qho nyuaj rau tshem tawm tom qab thiab ua raws li txoj kev tawg.
Kev soj ntsuam thiab cov ntsiab lus zoo
Txheeb xyuas qhov chaw cog qoob loo thiab pov tseg qhov hnyav, kom cov yeeb nkab shrinkage raug tshem tawm tag nrho.
Sau lub diffusion anneal voj voog, vim nyob rau hauv -soaking nplooj segregation uas forge tsis tuaj yeem tshem tawm.
Tswj lub forging pib thiab tag kub, tsis muaj reheating uas coarsens cov nplej.
Tswj tus ncej-forging txias npaum li cas kom tsis txhob carbide tes hauj lwm nyob rau hauv lub grain ciam teb.
Tshawb xyuas spheroidize annealing los ntawm hardness thiab los ntawm metallographic kev ntsuam xyuas ntawm carbide puab thiab tis.
Ntsuas carbide banding, decarburisation qhov tob thiab lub suab sab hauv ua ntej qhov khoob raug tso tawm mus rau machining.
FAQ
Q: Vim li cas lub sab saum toj ntawm ingot cropped?
Nws muaj cov yeeb nkab shrinkage thiab kev sib cais tsis zoo, uas tsis tuaj yeem kho tom qab ntawm tus txheej txheem.
Q: Dab tsi yog diffusion annealing ua tiav?
Nws txo macrosegregation thiab softens lub ingot, muab ib tug ntau yam qauv ua ntej forging.
Q: Vim li cas lub ingot chim siab rau polyhedron ua ntej?
Ua hauj lwm cov hlau nyob rau hauv ntau cov lus qhia lov lub dendritic network thiab disperses banded carbides.
Q: Lub hom phiaj ntawm spheroidize annealing yog dab tsi?
Nws tsim globular carbides nyob rau hauv ib tug ferritic matrix, txo hardness rau machining thiab npaj cov qauv rau hardening.
Q: Yuav ua li cas yog network carbides tshem tawm?
Kev kho mob normalizing yog siv los rhuav lub network ua ntej spheroidize annealing.
Q: Puas yog txoj kev forging raug nqi ntau dua?
Yog lawm, qhov ingot, diffusion anneal thiab forging sequence raug nqi ntau dua li nruam casting, tab sis nws muab cov qauv zoo dua qub thiab kev ntseeg siab dua.
