Kev kho cua sov yog ib txoj hauv kev nrov los hloov kho cov khoom ntawm qee yam hlau. Ib txoj hauv kev zoo tshaj plaws los hloov cov hlau rau qhov xav tau ntawm ib puag ncig lossis daim ntawv thov yog tuaj yeem hloov kho nws lub zog, toughness, thiab hardness yam tsis hloov pauv nws cov tshuaj muaj pes tsawg leeg. Hlau tuaj yeem kho cua sov hauv ntau txoj hauv kev, tab sis quenching yog ib txoj hauv kev siv ntau tshaj plaws.
Quenching yog dab tsi?
quenching yog ib kauj ruam hauv ntau cov txheej txheem kho cua sov uas muaj cua sov rau qhov yuav tsum tau kub thiab muab tso rau hauv qhov nruab nrab quenching kom txias sai. Lwm cov txheej txheem kev kho cua sov feem ntau ua raws li quenching, xws li kev laus, tempering, lossis annealing kom ua tiav qhov xav tau. Los ntawm kev ua kom txias sai sai ntawm cov hlau, koj tuaj yeem tiv thaiv lossis txhawb kev tsim cov microstructures sib txawv hauv cov hlau kom ua tiav cov khoom koj xav tau rau daim ntawv thov.
Ntau hom crystalline microstructures muaj xws li:
· Austenite: Austenite cov ntaub ntawv thaum hlau yog rhuab thaum hlau ua hauj lwm. Nws yog ib qho tawv tsis tau tsim microstructure uas zoo heev rau vuam. Austenitic steel muaj ntau yam kev siv, tab sis nws feem ntau ua haujlwm ntxiv los tsim cov hlau martensitic.
· Martensite: Martensitic transformation yog dab tsi tshwm sim thaum koj txias rhuab hlau sai. Thaum martensitic steel yog ib qho nyuaj, nws kuj yog nkig heev. Ua hauj lwm cov hlau tom qab quenching pab kom rov qab tau qee qhov ductility rau nws thiab txo cov kev ntxhov siab sab hauv.
· Ferrite: Ferrite yog mos, thermodynamically ruaj khov microstructure uas tsim ua ntej hloov mus rau hauv austenite. Nws feem ntau tshwm sim hauv cov hlau tsis tshua muaj carbon.
· Cementite: Cementite yog ib qho thermodynamically unstable microstructure uas muaj hlau thiab carbon. Nws nruj microstructure ua rau ib qho nyuaj heev tab sis nkig hlau.
· Pearlite: Kev ua kom txias qeeb ua rau pearlite microstructure, uas yog tsim los ntawm cov txheej txheem sib hloov ntawm ferrite thiab cementite. Cov qauv no muaj zog thiab hnav nrog siab hnav tsis kam.
· Npav: Bainite yog ib qho nyuaj, nkig microstructure uas tsim thaum cov hlau tivthaiv yog txias sai dua qhov txias ntawm pearlite tab sis qeeb dua martensite.
Hom Quenching Media
Cov txheej txheem quenching tuaj yeem ua tiav siv ntau yam ntawm quenching media. Txhua qhov nruab nrab muaj qhov tshwj xeeb quenching zoo ntawm nws tus kheej. quenching ceev, quenching ib puag ncig teeb meem, quenching xov xwm hloov, thiab quenching media nqi yog yam yuav tsum tau coj mus rau hauv tus account thaum txiav txim siab hom kev siv xov xwm.Ntawm no yog cov hom tseem ceeb ntawm quenching media:
Cua
Cua yog ib qho nrov quenching media siv los txias hlau rau quenching. Kev them taus yog ib qho txiaj ntsig tseem ceeb ntawm huab cua; nws txoj kev them taus yog qhov tshwm sim ntawm nws txoj kev loj hlob hauv ntiaj teb. Qhov tseeb, txhua yam khoom uas tau ua kom sov thiab tom qab ntawd tso cai rau txias rau hauv chav sov tsuas yog los ntawm kev tso tseg ib leeg yog suav tias yog cua quenched. Huab cua quenching kuj yog ua kom txhob txwm ua thaum nws yog compressed thiab yuam ib ncig ntawm cov hlau raug quenched. Qhov no ua rau qhov txias sai dua li huab cua, txawm tias huab cua compressed tseem tuaj yeem txias ntau cov hlau qeeb heev los hloov cov khoom siv kho tshuab.
Dej
Dej muaj peev xwm quench rhuab hlau sai heev thiab. Hlau tej zaum yuav txias sai sai los ntawm quenching nws nyob rau hauv dej, uas yog zoo rau mus txog lub siab tshaj plaws hardness nyob rau hauv tej daim ntawv thov. Txawm li cas los xij, vim muaj qhov nro sab hauv, nws cov cua txias tuaj yeem ua rau muaj kev cuam tshuam thiab tawg. Yog li ntawd, cov txheej txheem metallurgical ntxiv yog xav tau los ua kom tiav cov khoom.
Dej, zoo li ntau cov pa roj, tau yooj yim tau thiab tsis muaj kev cuam tshuam rau ib puag ncig, ua rau nws qhov nruab nrab quenching. Cov hnab ntim hauv chav tuaj yeem cuam tshuam cov txheej txheem ntawm quenching nrog dej; Yog tias qhov no tshwm sim, tus kws tsim hluav taws xob yuav tsum swirl cov khoom hauv nruab nrab kom cov huab cua ntub dej los ntawm kev tsim thiab nthuav tawm cov kab mob.
Roj
Roj muaj peev xwm quench rhuab hlau ntau sai dua li compressed cua. Ib lub ntsiab lus uas tau ua kom sov yog muab tso rau hauv lub tank uas muaj roj kom quenched. Ib feem kuj tuaj yeem yaug nrog roj. Vim tias cov roj sib txawv muaj qhov sib txawv ntawm qhov txias txias thiab cov ntsiab lus flash, lawv nquag ua haujlwm hauv ntau daim ntawv thov.
Brine
Brine, los yog dej ntsev, ua rau ib qho zoo heev quenching nruab nrab kom txias ceev. Nws txias sai dua huab cua, dej, thiab roj. Qhov no yog vim hais tias, thaum sib tov ntawm ntsev thiab dej los rau hauv kov nrog ib tug kub hlau, nws tiv thaiv cov creation ntawm huab cua globules. Yog li ntawd, cov kua yuav npog ib feem ntawm cov hlau saum npoo ntau dua li cov pa npuas yuav.
Quench Hardening hlau
Hlau tsim nyog tau txais ib qho tshwj xeeb hais thaum cov txheej txheem quenching tau tham vim tias nws cov khoom siv tshuab yog qhov nkag siab zoo rau quenching. Los ntawm cov txheej txheem quenching hu ua quench hardening, steel yog nce mus rau qhov kub siab tshaj nws qhov kub thiab txias recrystallization thiab txias sai heev ntawm cov txheej txheem quenching. Qhov ceev ceev quenching hloov cov qauv siv lead ua ntawm cov hlau, piv nrog qhov txias txias. Nyob ntawm cov ntsiab lus carbon thiab alloying cov ntsiab lus ntawm cov hlau, nws tuaj yeem tawm nrog ib qho nyuaj, nkig ntau dua microstructure, xws li martensite lossis bainite, thaum nws dhau los ua cov txheej txheem quench hardening. Cov microstructures no ua rau muaj zog ntxiv thiab hardness rau cov hlau. Txawm li cas los xij, lawv tawm ntawm cov hlau tsis yooj yim rau kev tawg thiab nrog kev txo qis hauv ductility. Vim li no, qee cov hlau yog annealed lossis normalized tom qab quench hardening txheej txheem.
