Vim muaj qhov kub thiab txias thaum lub sij hawm forging thiab ua cov forgings, qhov muaj tempering kub yog txwv. Txhawm rau tiv thaiv brittleness los ntawm kev nce thaum lub sij hawm tempering, nws yog ib qho tsim nyog kom tsis txhob muaj ob qhov kub thiab txias, uas ua rau nws nyuaj rau kho cov khoom siv kho tshuab. Thawj hom temper brittleness. Thawj hom temper brittleness uas tshwm sim thaum tempering ntawm 200 thiab 350 ℃ kuj hu ua low-temperature temper brittleness. Yog hais tias thawj hom temper brittleness tshwm sim thiab ces rhuab mus rau ib tug ntau dua kub rau tempering, lub brittleness yuav raug tshem tawm thiab tej yam toughness yuav tsum tau ntxiv dua. Nyob rau lub sijhawm no, yog tias tempered nyob rau hauv qhov kub ntawm 200-350 ℃, qhov brittleness yuav tsis tshwm sim. Los ntawm qhov no, nws tuaj yeem pom tau tias thawj hom temper brittleness yog irreversible, li no nws tseem hu ua irreversible temper brittleness. Qhov thib ob hom temper brittleness. Ib qho tseem ceeb ntawm temper brittleness nyob rau hauv lub thib ob hom forged zog yog hais tias, nyob rau hauv tas li ntawd mus ua brittleness thaum lub sij hawm qeeb txias thaum lub sij hawm tempering ntawm 450 thiab 650 ℃, maj mam dhau los ntawm lub brittle txoj kev loj hlob cheeb tsam ntawm 450 thiab 650 ℃ tom qab tempering ntawm siab dua kub. kuj ua rau brittleness. Yog tias cov cua txias sai dhau los ntawm qhov chaw tsim kho brittle tom qab kub-kub tempering, nws yuav tsis ua rau embrittlement. Qhov thib ob hom temper brittleness yog thim rov qab, yog li nws tseem hu ua reversible temper brittleness. Qhov thib ob ntawm temper embrittlement phenomenon yog qhov nyuaj heev, thiab sim piav qhia txhua qhov tshwm sim nrog ib txoj kev xav yog qhov nyuaj heev, vim tias yuav muaj ntau dua ib qho laj thawj rau embrittlement. Tab sis ib yam yog qhov tseeb, cov txheej txheem embrittlement ntawm ob hom temper brittleness yog inevitably ib tug reversible txheej txheem uas tshwm sim nyob rau hauv lub grain ciam teb thiab yog tswj los ntawm diffusion, uas yuav ua rau tsis muaj zog ntawm grain ciam teb thiab tsis ncaj qha mus rau martensite thiab residual austenite. Nws zoo nkaus li tsuas muaj ob qhov ua tau rau cov txheej txheem thim rov qab no, uas yog kev sib cais thiab ploj ntawm cov atoms ntawm cov ciam teb, thiab nag lossis daus thiab tawg ntawm nkig theem raws li cov ciam teb.
Lub hom phiaj ntawm tempering hlau tom qab quenching thaum lub sij hawm forging thiab ua cov forgings yog: 1. txo brittleness, tshem tawm los yog txo cov kev ntxhov siab. Tom qab quenching, steel qhov chaw muaj qhov tseem ceeb hauv kev ntxhov siab thiab brittleness, thiab tsis ua kom npau taws raws sijhawm feem ntau ua rau deformation los yog tawg ntawm cov hlau. 2. Tau txais cov khoom siv kho tshuab uas xav tau ntawm cov khoom ua haujlwm. Tom qab quenching, lub workpiece muaj siab hardness thiab siab brittleness. Txhawm rau ua kom tau raws li qhov sib txawv ntawm kev ua haujlwm ntawm ntau yam khoom siv, lub hardness tuaj yeem hloov kho los ntawm qhov tsim nyog tempering kom txo qis brittleness thiab tau txais qhov yuav tsum tau toughness thiab plasticity. 3. Stabilize lub workpiece loj. 4. Rau qee cov hlau alloy uas nyuaj rau soften tom qab annealing, high-temperature tempering yog feem ntau siv tom qab quenching (los yog normalizing) kom tsim nyog aggregate carbides nyob rau hauv cov hlau, txo hardness, thiab pab txiav txiav.
Thaum forging forgings, temper brittleness yog ib qho teeb meem uas yuav tsum tau muab sau tseg. Nws txwv qhov ntau ntawm tempering kub muaj, raws li qhov kub thiab txias uas ua rau kom brittleness ntxiv yuav tsum tau zam thaum lub sij hawm tempering. Qhov no ua rau muaj teeb meem hauv kev kho cov khoom siv kho tshuab.
Thawj hom temper brittleness feem ntau tshwm sim ntawm 200-350 ℃, tseem hu ua low-temperature brittleness. Qhov no brittleness yog irreversible. Thaum nws tshwm sim, rov ua kom sov rau qhov kub siab dua rau tempering tuaj yeem tshem tawm brittleness thiab txhim kho qhov cuam tshuam toughness dua. Txawm li cas los xij, tempering nyob rau hauv qhov kub ntawm 200-350 ℃ yuav ua rau qhov brittleness ib zaug ntxiv. Yog li ntawd, thawj hom temper brittleness yog irreversible.
Ib qho tseem ceeb ntawm hom thib ob ntawm temper brittleness yog qhov txias qeeb thaum lub sij hawm tempering ntawm 450 thiab 650 ℃ tuaj yeem ua rau brittleness, thaum maj mam dhau los ntawm qhov kev loj hlob ntawm brittle cheeb tsam ntawm 450 thiab 650 ℃ tom qab tempering ntawm kub dua tuaj yeem ua rau brittleness. Tab sis yog tias cov cua txias sai dhau los ntawm thaj tsam kev txhim kho brittle tom qab high-temperature tempering, brittleness yuav tsis tshwm sim. Hom thib ob ntawm temper brittleness yog thim rov qab, thiab thaum brittleness ploj mus thiab rov ua dua thiab maj mam txias dua, brittleness yuav rov qab los. Cov txheej txheem embrittlement no yog tswj los ntawm diffusion thiab tshwm sim ntawm cov ciam teb, tsis ncaj qha ntsig txog martensite thiab residual austenite.
Nyob rau hauv cov ntsiab lus, muaj ntau lub hom phiaj rau tempering hlau tom qab quenching thaum lub sij hawm forging thiab ua cov forgings: txo brittleness, tshem tawm los yog txo cov kev ntxhov siab nyob rau hauv, tau txais cov khoom uas yuav tsum tau, stabilizing workpiece loj, thiab adapting tej alloy steels uas nyuaj rau soften thaum annealing. txiav los ntawm high-temperature tempering.
Yog li ntawd, nyob rau hauv cov txheej txheem forging, nws yog ib qho tsim nyog yuav tsum tau ua tib zoo xav txog qhov cuam tshuam ntawm tempering brittleness, thiab xaiv qhov tsim nyog tempering kub thiab txheej txheem txheej txheem kom tau raws li qhov yuav tsum tau ntawm cov khoom, thiaj li ua tau zoo txhua yam khoom thiab stability.
Post lub sij hawm: Oct-16-2023
