Kuv Thaum tshav kub kub kho kab nrib pleb
Yam ntxwv:
Morphology: Thaum tshav kub kub kho cov kab nrib pleb feem ntau tsim nyob rau hauv martensitic transformation cheeb tsam, yog li lawv cov kab nrib pleb yuav tawg raws cov siv lead ua los yog tawg los ntawm cov siv lead ua. Cov kab nrib pleb tuaj yeem yog radial, cais kab lossis net.
Qhov chaw: Cov kab nrib pleb feem ntau yuav tshwm sim ntawm cov ces kaum ntse ntawm qhov chaw ua haujlwm, ntawm kev hloov pauv sai ntawm ntu ntu.
Seem: Cov seem ntawm qhov quenching tawg yog feem ntau tsis oxidized thiab tej zaum yuav dawb, npub dawb los yog lub teeb liab (dej xeb tshwm sim los ntawm quenching).
Ua rau:
Kev sib tsoo tshwm sim thaum qhov kev ntxhov siab loj uas tau tsim thaum lub sij hawm quenching ntau dua li cov khoom siv nws tus kheej lub zog thiab tshaj cov yas deformation txwv.
Tej zaum nws yuav cuam tshuam rau yam xws li kub kub quenching kub thiab txias ceev heev.
Yog vim li cas rau kev kho cua sov tawg
a. Khoom siv metallurgical zoo:
Metallurgical teeb meem xws li shrinkage thiab loj dov tsis xws luag yuav ua rau cov khoom inhomogeneities uas ua rau muaj kev pheej hmoo ntawm quenching tawg.
Metallurgical defects xws li macroscopic segregation, solid solution segregation, solid solution hydrogen, forging and rolling defects, slag entrapment, ferrite-pearlitic banding organization thiab carbide banding organization yuav ua ib leeg los yog ua ke nrog macroscopic lossis microscopic internal stresses ua rau quenching tawg.
b. Cov khoom siv carbon cov ntsiab lus thiab alloying ntsiab:
Kev nce hauv cov ntsiab lus ntawm cov pa roj carbon monoxide yuav txo qis lub zog tawg ntawm martensite, yog li ua kom muaj kev nyiam ntawm quenching tawg.
Alloying cov ntsiab lus xws li Mn, Cr, V, Mo, thiab lwm yam yuav ua rau kom muaj kev xav ntawm quenching kab nrib pleb nrog qhov nce ntawm nws cov ntsiab lus.
Txawm li cas los xij, lub caij B tuaj yeem txhim kho qhov kev ua tau zoo, thaum qhov tsim nyog ntawm cov ntsiab lus tsis tshua muaj hauv ntiaj teb tuaj yeem txo qhov kev sib txhuam uas xav tau rau kev txav mus los, txo qhov nyiam ua rau tawg tawg.
c. Cov txheej txheem quenching:
Kev tswj tsis raug ntawm quenching cua sov txoj kev thiab cua sov tus nqi, cua sov tsis sib xws, thiab kub quenching siab heev yuav ua rau quenching tawg.
quenching cua txias txoj kev tsis tsim nyog, qhov cua txias yog ceev heev, txias tsis sib xws, nrog rau kev xaiv tsis raug ntawm cov cua txias nruab nrab kuj yog ib qho ua rau.
quenching ua ntej lub workpiece tsis npaj rau kev kho cua sov los yog kev kho mob tsis raug, nrog rau tempering tsis raws sij hawm kuj yuav ua rau quenching tawg.
d. Qhov loj thiab cov duab ntawm lub workpiece:
Lub kaum ntse ntse ntawm cov khoom ua haujlwm, kev hloov pauv ntawm ntu ntu yog qhov tsim nyog rau kev tsim cov quenching tawg, vim tias cov chaw no muaj kev ntxhov siab ntau.
Cov ncej loj loj yog qhov ua rau thermal stress-induced tawg yog tias lawv tsis raug quenched thaum quenching.
e. Internal defects:
Cov teeb meem uas twb muaj lawm nyob rau hauv cov khoom, xws li vapor npuas, inclusions, hairline, dawb me ntsis, thiab lwm yam, tej zaum yuav dhau los ua ib qho ntawm cov kab nrib pleb nyob rau hauv qhov kev txiav txim ntawm kev kho cua sov kev nyuaj siab thiab maj mam nthuav.
f. Martensite intrinsic brittleness:
Lub intrinsic brittleness ntawm martensite yog qhov ua rau quenching tawg, thiab nws cov qauv siv lead ua, tshuaj muaj pes tsawg leeg, metallurgical tsis xws luag, thiab lwm yam.
Quenching cov kab nrib pleb yog qhov tshwm sim los ntawm kev sib xyaw ua ke, thiab yuav tsum tau txiav txim siab thiab ua kom zoo rau ntau yam, xws li kev xaiv cov khoom siv, kev tswj cov txheej txheem, kev tsim cov khoom ua haujlwm, thiab lwm yam, txhawm rau txo qhov kev pheej hmoo ntawm Quenching cov kab nrib pleb.
Yam ntxwv:
Morphology: forging cov kab nrib pleb yog tsim los ntawm qhov kub thiab txias, cov kab nrib pleb yog tuab thiab feem ntau muaj nyob rau hauv daim ntawv ntawm ntau lub strips, tsis muaj qhov zoo, tsis muaj kev coj zoo. Qee zaum nyob ib ncig ntawm qhov tawg tsis yog tag nrho decarburised tab sis semi-decarburised.
Txoj hauj lwm: feem ntau ua nyob rau hauv lub coarse organization, kev nyuaj siab concentration los yog alloying ntsiab ntawm lub segregation.
Ntu ntu: qhov tawg tuaj yeem yog xim av tsaus, lossis txawm tias muaj cov tawv nqaij ntawm cov pa oxygen, qhov no yog vim qhov tawg ntawm forging deformation kom nthuav dav thiab sib cuag nrog huab cua.
Ua rau:
Raw khoom defects:
Residual shrinkage: Tsis tiav kaw qhov pores lossis qhov hauv cov khoom siv raw tuaj yeem ua rau txo qis lub zog ntawm cov khoom thaum lub sijhawm forging, uas ua rau nws yooj yim los tsim cov kab nrib pleb.
Inclusions nyob rau hauv steel:
non-metallic inclusions, carbide segregation, heterogeneous hlau inclusions nyob rau hauv cov ntaub ntawv raw tej zaum yuav tsis muaj zog lub continuation ntawm cov khoom thiab txhawb kev tsim cov kab nrib pleb.
Txoj kev forging tsis raug:
cua sov tsis raug:
Cov cua kub kub yog siab dhau los yog qis dhau, uas tuaj yeem ua rau tsis sib xws ntawm kev ntxhov siab hauv cov khoom siv, uas ua rau tawg tawg thaum lub sij hawm forging.
deformation tsis zoo:
qhov deformation tus nqi yog loj heev, lub plasticity ntawm cov hlau tsis txaus los tiv thaiv cov duab ntawm lub siab, yooj yim rau rupture. Qhov kev tawg no feem ntau tshwm sim thaum pib ntawm forging theem, thiab nthuav dav sai.
Tsis zoo txias tom qab forging:
qhov txias txias yog nrawm dhau los yog qeeb dhau, tuaj yeem ua rau muaj kev ntxhov siab hauv cov khoom siv, ua rau tawg.
Kev kho cua sov tsis raws sijhawm:
tom qab forging tsis raws sijhawm thiab kev kho cua sov tsim nyog, tuaj yeem ua rau cov khoom siv hauv kev ntxhov siab tsis zoo tso tawm, yog li ua rau muaj kev pheej hmoo ntawm kev tawg.
g. Kev tswj kub tsis raug:
Hauv cov txheej txheem cua sov thiab cua txias, yog tias qhov ntsuas kub tsis raug tswj tau zoo, nws yuav ua rau muaj kev ntxhov siab ntau dhau ntawm cov khoom, yog li ua rau tawg. Piv txwv li, nyob rau hauv cov txheej txheem quenching, yog tias qhov txias yog ceev heev, quenching tawg yuav tshwm sim.
h. Material stress concentration:
Yog hais tias muaj kev ntxhov siab nyob rau hauv lub forging, xws li cov ces kaum ntse thiab hla ntu kev hloov pauv, thaum qhov kev ntxhov siab dhau ntawm cov khoom muaj peev xwm, nws yuav ua rau tawg.
