Lub hom phiaj yog dab tsi npau taws rau cov pa hluav taws xob cov hlau?
Kev ntsuas hluav taws xob carbon ua ke rau cov hlau quenched rau qhov kub siab hauv qab no AC1 (kev tuav nws rau lub sijhawm lossis maj mam txias. Nws cov haujlwm tseem ceeb yog txhawm rau kho cov khoom ua tiav tom qab thiab "qhov kev ua tiav" cov khoom siv me me, ua tiav qhov sib npaug, hardness, kev nruj, thiab ductility. Qhov no tuaj yeem faib rau hauv tsib lub luag haujlwm tseem ceeb:
1. Tshem tawm cov kev ntxhov siab sab hauv kev ntxhov siab los tiv thaiv kev tawg lossis deformation hauv feem
Txheej txheem txias nrawm thaum lub sij hawm quenching tuaj yeem ua rau muaj kev ntxhov siab sab hauv kev ntxhov siab hauv cov hlau. Qhov no feem ntau yog vim ob qhov chaw:
Kev ntxhov siab tectonic: Thaum Austenite sai hloov mus rau martensite, nws cov ntim nthuav dav (martensite loj dua Austenite los ntawm ntim). Txawm li cas los xij, cov nqi sib txawv ntawm cov ntu sib txawv ntawm cov ntu sib txawv, lossis cov npoo}} pa taws qhov kev hloov pauv thiab tsim cov kev ntxhov siab sab hauv.
Thermal Kev ntxhov siab: Thaum lub sijhawm txias txias, qhov kub ntawm qhov tseem ceeb, ua rau muaj qhov tseem ceeb dua li cov tub ntxhais, ua rau muaj kev ntxhov siab tensile thiab compressive kev ntxhov siab.
If these internal stresses are not eliminated, at best, they can cause deformation of the part during storage or processing (such as bending of shafts or warping of plates), or at worst, directly cause cracking (especially in high-carbon structural steel or large-cross-section parts). Thaum lub sij hawm tempering, atoms nce zog thaum cua sov, uas tuaj yeem txo qis kev dattice distortion los ntawm kev sib txawv thiab tshem tawm kev ntxhov siab, maj mam tso sab hauv kev ntxhov siab.
Piv txwv li, tom qab quenching, kev ntxhov siab sab hauv ntawm 45 hlau tuaj yeem ncav tau ntau pua MPA. Tom qab qes - kub npau taws ntawm 200 degree, kev ntxhov siab no tuaj yeem tau txais kev pab cuam tshuam los ntawm 50% {} 60 7%. Tom qab high-kub tempering ntawm 500 degree, tus nqi ntxhov siab tuaj yeem ncav cuag ntau dua 80%, tiv thaiv kev tiv thaiv tsis ua haujlwm.
2. Txo cov brittleness thiab txhim kho cov hlau txoj kev nruj thiab muaj kuab yas
Txawm hais tias quenched carbon txheej txheem hlau muaj cov tawv tawv heev thiab lub zog, nws martensaturated daws teeb meem, "ua rau muaj kev sib txawv ntawm kev sib txawv thiab tsis tshua muaj kev cuam tshuam. Qhov no ua rau muaj kev tsis tshua muaj zog thiab tsis tshua muaj qoob loo. (Piv txwv li, qhov cuam tshuam lub zog ntawm quenched 45 steel tsuas yog 5-10J, ua rau nws tsis haum rau qhov tsis tsim nyog siv raws li cov khoom tiav. Ib qho ntawm cov haujlwm tseem ceeb ntawm tempering yog los txo brittleness. Thaum lub sijhawm ua cua sov, cov roj pleev cov roj ua ntej los ntawm cov martensite (ua kom maj mam marty), txo qis zuj zus mus rau kev tshem tawm cov kev tawm tsam thiab kev sib txuas.
Piv txwv li, 45 hlau muaj qhov cuam tshuam lub zog nqus nqus ntawm kwv yees li 8J tom qab quenching (untempered). Lub zog no nce mus rau 15 {{{4 4}}} 20- kub kub, tab sis txaus rau qis {} kev siv cov ntawv thov tsawg). Tom qab high-kub tempering ntawm 550 degree, qhov cuam tshuam lub zog nqus nce mus nce dua 50j (txhim kho nws kom tiv thaiv kev cuam tshuam nruab nrab).
Rau siab siab -} cov hlau roj teeb (xws li 65 tus kheej txhim kho tom qab kev ua kom muaj zog ntxiv, tiv thaiv cov ntu kom yooj yim thaum raug rau sab nraud.
3. Kho kom haum hardness thiab lub zog kom tau raws li cov kev thov sib txawv
Tom qab quenching, hlau ncav cuag lub zog tawv thiab lub zog (piv txwv li lub zog (45-60 thiab lub zog tensile ntawm ntau dua 1000 tom qab quenching). Txawm li cas los xij, tsis yog txhua daim ntawv thov yuav tsum muaj kev nyuaj siab heev. Kev ua tau zoo yuav tsum muaj rau cov khoom sib txawv sib txawv (xws li cov cuab yeej xav tau kev sib npaug thiab kev sib npaug, thiab cov txuas yuav tsum muaj cov yees xeeb). Tempering tso cai kho kom haum ntawm hardness thiab lub zog los tswj cov cua sov kub:
Tsawg - kub tempering (150 {} Qhov no feem ntau siv hauv cov ntawv thov uas xav tau ob peb lub siab tawv thiab muaj qee yam kev txiav tawm thiab hnav cov khoom tawg-resistant bushings).
Nruab nrab - kub tempering (350- 500-grained cementite + ferrite), txo lub hardness), txo qhov nyuaj rau 100%. Ntawm HRC 35-45, lub zog tseem nyob ntawm 700-800 MPa, thaum lub elasticity tau txhim khu kev txhim kho (elastic txwv nce mus txog 300-400 mpa). Nws yog qhov tsim nyog rau springs thiab elastic Cheebtsam (xws li kev poob siab lub zog nqus dej txhaws thiab tshuab cuab tam chucks).
High - kub tempering (500 {2} {{10} {650 degree), ntxiv txo lub hardness rau hrc 25-35. Lub zog yog tswj ntawm 600-800 MPa, thiab cov tawv thiab kev sib luag tau txhim kho. Nws yog qhov haum rau cov chaw tseem ceeb uas yuav tsum tau sib npaug ntawm lub zog thiab lub zog, sib txuas microsctriling thiab qhov ntev los ua kom ntseeg tau ntev lub sij hawm ntev thiab kev ntseeg tau.
Quenched Martensite yog qhov tsis - kev sib npaug ntawm cov qauv hluav taws xob thiab maj mam hloov cov qauv rau kev sib npaug). Qhov no "kev laus" tuaj yeem ua rau cov hauv qab no thaum ub- kev siv lossis cia khoom:
Tsim kev tsim nyog: Martensite maj mam decomposes rau hauv Pearlite lossis cementite, uas ua rau ib qho kev kawm tiav hauv cov khoom (xws li hardness thiab elasticity);
Kev hloov pauv tsis txaus: Microstructural kev hloov pauv yog nrog cov kev hloov pauv me me, piv txwv li qhov tseeb tab sis cov khoom siv ntsuas cov kabmob thiab ntsuas cov cuab yeej).
Temperating nrawm kev ua kom nag thiab cov qauv cua sov (piv txwv li lub xeev siab dua (piv txwv li tsis muaj zog Qhov no ua rau:
Xauv lub Microstructure: Tiv thaiv kev ua tau zoo thaum lub sijhawm siv tom ntej;
Txhim kho qhov ntev: Tshem tawm qhov kev pheej hmoo ntawm "Kev Txom Nyem Kev Nyab Xeeb,"}}}}}}} Cov txheej txheem txuas ntxiv (txhim kho tshuab txuas ntxiv (txhim kho kev luam ntawv txuas ntxiv (txhim kho kev luam ntawv txuas ntxiv (txhim kho tshuab txuas ntxiv (txhim kho kev luam ntawv txuas ntxiv (txhim kho tshuab txuas ntxiv (txhim kho tshuab txuas ntxiv (txhim kho kev luam ntawv txuas ntxiv (txhim kho tshuab txuas ntxiv (txhim kho kev luam ntawv txuas ntxiv (txhim kho kev luam ntawv txuas ntxiv (txhim kho kev luam ntawv txuas ntxiv (txhim kho tshuab txuas ntxiv (txhim kho kev luam ntawv txuas ntxiv (txhim kho tshuab txuas ntxiv (txhim kho kev luam ntawv txuas ntxiv (txhim kho tshuab txuas ntxiv (txhim kho kev luam ntawv txuas ntxiv (txhim kho kev luam ntawv txuas ntxiv (txhim kho tshuab txuas ntxiv (txhim kho kev luam ntawv txuas ntxiv (txhim kho tshuab txuas ntxiv (txhim kho tshuab txuas ntxiv (txhim kho kev luam ntawv txuas ntxiv (txhim kho tshuab txuas ntxiv (txhim kho tshuab txuas ntxiv (txhim kho tshuab txuas ntxiv (txhim kho kev luam ntawv txuas ntxiv (txhim kho kev luam ntawv txuas ntxiv (txhim kho kev luam ntawv txuas ntxiv (txhim kho kev luam ntawv txuas ntxiv (txhim kho tshuab txuas ntxiv (txhim kho tshuab txuas ntxiv (txhim kho tshuab txuas ntxiv (txhim kho tshuab txuas ntxiv (txhim kho kev luam ntawv txuas ntxiv (txhim khu
Lub hardness ntawm quenched steel yog qhov siab heev (piv txwv li, 45 hlau nce mus txog HRC 55-60 tom qab quenching). Kev txiav ncaj qha ncaj qha (xws li tig thiab milling) ntsej muag ob qhov teeb meem loj:
Kev hnav sai sai hnav: high - Hardness} Lub Hardness Hlau sai sai hnav lub siab- cov nqi ceev;
Tsawg dawb machining precision: ntau dhau hardness tuaj yeem yooj yim coj mus chipping thiab chatter txiav, piv txwv, ua tiav tus nqi ra hauv qab 3.2μm).
Tempering lub stenched steel ntawm ib nrab {{0} heal} Kev kub siab tuaj yeem txo qhov nyuaj rau hrc 25} {- rau-txiav "ntau).
Txij ntawm no, tus hlau lub microstructure yog tempered troostite lossis tempered troostite, uas ua rau muaj kev nyuaj siab. Cov cuab yeej ua haujlwm yog tusyees faib thaum txiav, ua kom qeeb qeeb.
Cov roj hmab ntxiv kom tau nti (kev tiv thaiv cov cuab yeej ua kom tiav), txhim kho txoj kev ua kom tiav qis dua (org