Txhais:
Spheroidizing annealing yog txheej txheem annealing rau spheroidize carbide (cementite Fe3C) nyob rau hauv steel.The steel yog rhuab mus rau 20 ~ 30 degree saum Ac1, tuav rau ib lub sij hawm ntawm lub sij hawm, thiab ces maj mam txias mus rau ib tug kub me ntsis qis dua Ac1, thiab nyob twj ywm rau. ib lub sij hawm ntawm lub sij hawm, thiaj li hais tias lub koom haum transformation tiav, thiab lub koom haum ntawm spheroidal los yog granular carbide yog uniformly faib nyob rau hauv lub ferrite matrix.
Ntau yam ntawm kev thov:
Spheroidizing annealing yog tsuas yog siv rau eutectoid steel thiab hypereutectoid steel, xws li cov cuab yeej carbon steel, alloy cuab yeej steel, bearing steel thiab hais txog. Cov hlau yog cua txias tom qab dov thiab forging, thiab cov qauv tsim yog lamellar pearlite thiab mesh cementite, uas yog tawv thiab nkig, tsis tsuas yog nyuaj rau txiav, tab sis kuj yooj yim rau deform thiab tawg thaum lub sij hawm quenching txheej txheem. Lub spheroidizing annealing tau yog ib tug kheej kheej pearlite qauv, nyob rau hauv uas lub cementite yog kheej kheej hais, dispersed nyob rau hauv lub ferritic matrix, piv nrog flake pearlite, tsis tsuas yog tsawg hardness, yooj yim txiav, thiab nyob rau hauv lub quenching cua sov, austenite nplej tsis yooj yim. kom loj hlob, txias workpiece deformation thiab cracking nyiam yog me me. Tsis tas li ntawd, spheroidizing annealing kuj tseem siv tau rau qee cov hlau hypoeutectoid uas yuav tsum tau txhim kho cov yas deformation (xws li stamping, txias taub hau, thiab lwm yam).
Spheroidizing annealing kub kub yog Ac1 ntxiv (20 ~ 40) degree los yog Acm-(20 ~ 30) degree, thiab isothermal txias los yog ncaj qha qeeb txias tom qab tshav kub preservation. Hauv spheroidizing annealing, austenization yog "tsis tiav", tsuas yog cov flake pearlite hloov mus rau hauv austenite, thiab ib qho me me ntawm cov carbide ntau dhau yog yaj. Yog li ntawd, nws yog tsis yooj yim sua kom tshem tawm lub network carbide, xws li hypereutectoid steel network carbide tshwm sim, nws yuav tsum tau normalized ua ntej lub spheroidizing annealing, tshem tawm nws, thiaj li yuav xyuas kom meej cov txheej txheem ntawm spheroidizing annealing.
Cov txheej txheem:
Muaj ntau cov txheej txheem nodular annealing, thiab ob txoj kev siv feem ntau yog qhov zoo tib yam nodular annealing thiab isothermal nodular annealing. Ordinary spheroidizing annealing yog kom sov cov hlau mus rau 20 ~ 30 degree saum toj no Ac1, tuav lub cua sov rau ib lub sij hawm tsim nyog, thiab ces maj mam txias nrog lub cub tawg, txias mus txog 500 degree tawm ntawm qhov cub cua txias. Isothermal spheroidizing annealing yog tib yam li cov txheej txheem spheroidizing annealing zoo tib yam tom qab cua sov thiab tuav, nrog rau lub qhov cub txias kom sov me ntsis qis dua Ar1 lub sij hawm isothermal yog 1.5 npaug ntawm nws cov cua sov thiab tuav lub sij hawm. Tom qab isothermal txias nrog rau qhov cub kom txog 500 degree tawm ntawm cov cua txias. Piv nrog rau qhov zoo tib yam nodularization annealing, isothermal nodularization annealing tsis tsuas yog tuaj yeem ua rau lub voj voog luv, tab sis kuj tuaj yeem ua rau cov qauv nodularization zoo ib yam, thiab tuaj yeem tswj cov tawv tawv tom qab annealing.
Spheroidizing annealing yog tsuas yog siv rau ntau tshaj-eutectoid carbon steel thiab hlau alloy hlau (xws li steel siv nyob rau hauv manufacturing tej cuab yeej, ntsuas cov cuab yeej, pwm). Nws lub hom phiaj tseem ceeb yog txo qhov hardness, txhim kho lub machinability, thiab npaj rau tom qab quenching. Cov txheej txheem no yog qhov tsim nyog rau kev ua cov yas thiab txiav, tab sis kuj tseem txhim kho cov neeg kho tshuab toughness. Tshwj xeeb tshaj yog rau cov kabmob steel, cuab yeej steel thiab lwm yam hlau, xws li kev siv spheroidizing annealing ua ntej quenching, koj tuaj yeem tau txais cov teebmeem hauv qab no:
Bearing steel:uniform quenching nyhuv; Txo quenching deformation; Ua kom quenching hardness; Txhim kho workpiece txiav kev ua tau zoo; Txhim kho bearing zog xws li hnav tsis kam thiab pitting kuj.
Cov cuab yeej steel:uniform quenching nyhuv; Inhibition ntawm quenching cracking, quenching dabtsi yog khoov thiab lwm yam tshwm sim; Txhim kho hnav tsis kam, hniav sharpness thiab kev pab lub neej.
Raws li qib steel thiab lub hom phiaj ntawm annealing, nodular annealing tuaj yeem muab faib ua hom hauv qab no:
(1) Ordinary spheroidizing annealing, uas yog, cov hlau yog rhuab mus rau 730 ~ 740 degree C rau lub sij hawm txaus, thiab ces maj mam txias rau 650 degree C ntawm ib tug ceev ntawm tsawg tshaj li 20 degree C / h. Cov txheej txheem annealing no yog tsim rau cov cuab yeej carbon steels ze ntawm eutectoid muaj pes tsawg leeg.
(2) Periodic spheroidizing annealing, tseem hu ua cyclic annealing. Nws yog rov ua kom sov thiab txias ntawm qhov kub ntawm qhov ze ntawm A, feem ntau rau 3 mus rau 4 lub voj voog, kom cov flake pearlite yaj thiab precipitated ob peb zaug thaum rov ua dua, thiab cov carbide nodulated. Cov txheej txheem muaj lub voj voog ntau lawm ntev, kev ua haujlwm tsis yooj yim thiab kev tswj xyuas nyuaj, thiab tsim nyog rau cov hlau nrog pearlite loj.
(3) isothermal spheroidizing annealing. Feem ntau, nws yog rhuab mus rau 800 ± 10 ° C, thiab tom qab ntawd txias rau 700 ± 10 ° C (ze A1) ntev ntev tom qab rwb thaiv tsev, thiab tom qab ntawd txias rau 600 ° C ntawm qhov ceev ntawm 30 ~ 50 ° C / h. . General bearing steel feem ntau siv cov txheej txheem no.
(4) Deformation - spheroidizing annealing. Thaum cov yas deformation yog ua ke nrog spheroidizing annealing txheej txheem, qhov ceev thiab distortion ntawm dislocation nyob rau hauv steel yog nce vim yas deformation, uas yuav ua rau kom lub dissolution thiab spheroidization ntawm flake carbide thaum lub sij hawm annealing, yog li ceev tus nqi ntawm spheroidization thiab shortening lub sij hawm. spheroidization.
