Qhov sib txawv ntawm BK, GBK, BKS, NBK hauv STEEL.

Qhov sib txawv ntawm BK, GBK, BKS, NBK hauv STEEL.

TSAB NTAWV:

Annealing thiab normalizing hlau yog ob qho kev kho cua sov.
Lub hom phiaj ntawm kev kho cua sov ua ntej: txhawm rau tshem tawm qee qhov tsis xws luag hauv qhov khoob thiab cov khoom ua tiav ib nrab, thiab npaj lub koom haum rau kev ua haujlwm txias tom qab thiab kev kho cua sov zaum kawg.
Lub hom phiaj ntawm kev kho cua sov zaum kawg: kom tau txais qhov kev ua tau zoo ntawm lub workpiece.
Lub hom phiaj ntawm annealing thiab normalizing yog tshem tawm tej yam tsis xws luag tshwm sim los ntawm kub ua cov hlau, los yog npaj rau kev txiav tom ntej thiab zaum kawg kev kho cua sov.

 Annealing ntawm steel:
1. Lub tswv yim: Cov txheej txheem kev kho cua sov ntawm cov cua sov steel qhov chaw kom haum rau qhov kub thiab txias (saum toj no lossis qis dua Ac1), ua kom nws nyob rau lub sijhawm, thiab tom qab ntawd maj mam txias kom tau txais cov qauv nyob ze rau qhov sib npaug yog hu ua annealing.
2. Lub hom phiaj:
(1) Txo hardness thiab txhim kho plasticity
(2) Txhim kho cov nplej thiab tshem tawm cov txheej txheem tsis xws luag
(3) Tshem tawm kev ntxhov siab sab hauv
(4) Npaj lub koom haum rau quenching
Hom: (Raws li qhov kub thiab txias, nws tuaj yeem muab faib ua annealing saum toj no lossis qis dua qhov kub thiab txias (Ac1 lossis Ac3)). spheroidizing annealing; Cov tom kawg suav nrog recrystallization annealing thiab kev ntxhov siab nyem annealing.)

•  Ua kom tiav annealing (GBK + A):

1) Lub tswv yim: Thaum tshav kub kub ntawm cov hlau hypoeutectoid (Wc = 0.3% ~ 0.6%) rau AC3 + (30 ~ 50) ℃, thiab tom qab nws tau ua tiav austenitized, txuag hluav taws xob thiab ua kom txias txias (tom qab lub cub tawg, faus rau hauv xuab zeb, txiv qaub), Cov txheej txheem kev kho cua sov kom tau txais cov qauv nyob ze rau lub xeev sib npaug yog hu ua tiav annealing.2) Lub hom phiaj: Kho cov nplej, cov qauv zoo ib yam, tshem tawm cov kev ntxhov siab sab hauv, txo cov tawv tawv, thiab txhim kho kev ua haujlwm.
2) Cov txheej txheem: ua kom tiav annealing thiab qeeb txias nrog lub cub tawg tuaj yeem ua kom cov nag lossis daus ntawm proeutectoid ferrite thiab hloov pauv ntawm supercooled austenite rau hauv pearlite hauv qhov kub thiab txias hauv qab Ar1.Lub sijhawm tuav ntawm lub workpiece ntawm qhov kub ntawm qhov annealing tsis tsuas yog ua rau lub workpiece kub hnyiab tau, uas yog, cov tub ntxhais ntawm lub workpiece ncav cuag qhov xav tau cua sov kub, tab sis kuj xyuas kom meej tias tag nrho cov homogenized austenite pom kom ua tiav recrystallization.Lub sijhawm tuav ntawm kev ua tiav annealing muaj feem xyuam rau cov khoom xws li steel muaj pes tsawg leeg, workpiece thickness, lub cub tawg loading peev xwm thiab lub cub tawg txoj kev.Hauv kev tsim khoom tiag tiag, txhawm rau txhim kho kev tsim khoom, kev sib tsoo thiab cua txias txog li 600 ℃ tuaj yeem tawm ntawm qhov cub thiab cua txias.
Scope ntawm daim ntawv thov: casting, vuam, forging thiab dov ntawm nruab nrab carbon steel thiab nruab nrab carbon alloy steel, thiab lwm yam. Nco ntsoov: Tsawg carbon steel thiab hypereutectoid steel yuav tsum tsis txhob tag nrho annealed.Lub hardness ntawm qis carbon steel yog tsawg tom qab tau tag nrho annealed, uas yog tsis conducive rau txiav ua.Thaum lub hypereutectoid steel yog rhuab mus rau austenite lub xeev saum toj no Accm thiab maj mam txias thiab annealed, ib tug network ntawm theem nrab cementite yog precipitated, uas ho txo ​​lub zog, plasticity thiab tej yam toughness ntawm hlau.

• Spheroidizing annealing:

1) Lub tswv yim: Cov txheej txheem annealing rau spheroidize carbides hauv hlau yog hu ua spheroidizing annealing.
2) Txheej txheem: General spheroidizing annealing txheej txheem Ac1 + (10 ~ 20) ℃ yog txias nrog rauv rau 500 ~ 600 ℃ nrog cua txias.
3) Lub hom phiaj: txo hardness, txhim kho lub koom haum, txhim kho plasticity thiab txiav kev ua tau zoo.
4) Scope ntawm daim ntawv thov: tsuas yog siv rau kev txiav cov cuab yeej, ntsuas cov cuab yeej, pwm, thiab lwm yam ntawm eutectoid steel thiab hypereutectoid steel.Thaum cov hlau hypereutectoid muaj ib lub network ntawm cov cementite theem nrab, nws tsis tsuas yog muaj zog hardness thiab nyuaj rau kev txiav, tab sis kuj ua rau cov hlau brittleness, uas yog nquag quenching deformation thiab tawg.Vim li no, cov txheej txheem spheroidizing annealing yuav tsum tau ntxiv tom qab kev ua haujlwm kub ntawm cov hlau kom spheroidize cov flake infiltrate nyob rau hauv cov reticulated secondary cementite thiab pearlite kom tau granular pearlite.
Txias tus nqi thiab isothermal kub kuj yuav cuam tshuam cov nyhuv ntawm carbide spheroidization.Cov cua txias ceev los yog qhov kub tsis tshua muaj isothermal yuav ua rau pearlite tsim ntawm qhov kub thiab txias.Cov carbide hais yog qhov zoo heev thiab cov txiaj ntsig sib sau ua ke me me, uas ua rau nws yooj yim los tsim flaky carbides.Yog li ntawd, lub hardness yog siab.Yog tias qhov txias txias qeeb dhau los yog qhov kub ntawm isothermal siab dhau lawm, cov khoom carbide tsim yuav coarser thiab cov nyhuv agglomeration yuav muaj zog heev.Nws yog ib qho yooj yim los tsim granular carbides ntawm txawv thickness thiab ua rau hardness tsawg.

•  Homogenization annealing (diffusion annealing):

1) Cov txheej txheem: Cov txheej txheem kev kho cua sov ntawm cov cua sov alloy steel ingots lossis castings rau 150 ~ 00 ℃ saum Ac3, tuav rau 10 ~ 15h thiab maj mam txias kom tshem tawm cov tshuaj tsis sib xws.
2) Lub Hom Phiaj: Tshem tawm dendrite cais thaum lub sij hawm crystallization thiab homogenize muaj pes tsawg leeg.Vim qhov kub thiab txias thiab lub sijhawm ntev, cov nplej austenite yuav raug coarsened hnyav heev.Yog li ntawd, nws yog ib qho tsim nyog yuav tau ua kom tiav annealing los yog normalizing kom zoo cov nplej thiab tshem tawm overheating defects.
3) Scope ntawm daim ntawv thov: feem ntau yog siv rau alloy steel ingots, castings thiab forgings nrog zoo siab.
4) Nco tseg: Kub diffusion annealing muaj lub voj voog ntev ntau lawm, kev siv hluav taws xob siab, oxidation loj thiab decarburization ntawm lub workpiece, thiab tus nqi siab.Tsuas yog qee qhov zoo alloy steels thiab alloy steel castings thiab steel ingots nrog hnyav segregation siv cov txheej txheem no.Rau castings nrog qhov loj me me lossis carbon steel castings, vim tias lawv cov qib sib dua ntawm kev sib cais, ua kom tiav annealing tuaj yeem siv los kho cov nplej thiab tshem tawm kev ntxhov siab.

• Kev nyuaj siab nyem annealing

1) Lub tswv yim: Annealing kom tshem tawm qhov kev ntxhov siab los ntawm kev ua cov yas deformation, vuam, thiab lwm yam.(Tsis muaj distortion tshwm sim thaum lub sij hawm kev ntxhov siab annealing)
2) Txheej txheem: maj mam ua kom sov lub workpiece mus rau 100 ~ 200 ℃ (500 ~ 600 ℃) hauv qab Ac1 thiab khaws cia rau ib lub sijhawm (1 ~ 3h), ces maj mam txias rau 200 ℃ nrog rau qhov cub, thiab tom qab ntawd txias. nws tawm ntawm qhov cub.
Hlau feem ntau yog 500 ~ 600 ℃
Cam khwb cia hlau feem ntau tshaj 550 buckles ntawm 500-550 ℃, uas yuav yooj yim ua rau graphitization ntawm pearlite.Vuam qhov feem ntau yog 500 ~ 600 ℃.
3) Scope ntawm daim ntawv thov: Tshem tawm cov kev ntxhov siab nyob rau hauv cam khwb cia, forged, welded qhov chaw, txias stamped qhov chaw thiab machined workpieces kom stabilize qhov loj ntawm steel qhov chaw, txo deformation thiab tiv thaiv cracking.

Normalizing ntawm steel:
1. Lub tswv yim: cua sov cov hlau kom 30-50 ° C saum Ac3 (los yog Accm) thiab tuav nws rau lub sij hawm tsim nyog;Cov txheej txheem kev kho cua sov ntawm cov cua txias hauv cov cua tseem hu ua normalizing steel.
2. Lub hom phiaj: Refine grain, uniform qauv, kho hardness, thiab lwm yam.
3. Lub koom haum: Eutectoid steel S, hypoeutectoid steel F + S, hypereutectoid steel Fe3CⅡ + S
4. txheej txheem: Normalizing tshav kub preservation lub sij hawm yog tib yam li ua tiav annealing.Nws yuav tsum tau ua raws li lub workpiece los ntawm kev kub hnyiab, uas yog, cov tub ntxhais mus txog qhov yuav tsum tau ua kom sov qhov kub thiab txias, thiab cov yam ntxwv xws li steel, thawj cov qauv, qhov cub muaj peev xwm thiab cov khoom siv cua sov yuav tsum tau txiav txim siab.Feem ntau siv cov txheej txheem ua kom txias txias yog tshem cov hlau tawm ntawm lub qhov cub cua sov thiab txias nws hauv huab cua.Rau qhov loj, tshuab, txau thiab kho qhov kev ncua deb ntawm cov hlau qhov chaw kuj tuaj yeem siv los tswj cov cua txias ntawm cov hlau qhov chaw kom ua tiav lub koom haum thiab kev ua haujlwm.

5. Kev siv ntau yam:

• 1) Txhim kho qhov kev ua haujlwm ntawm cov hlau.Cov pa roj carbon steel thiab cov hlau tsis tshua muaj hlau nrog cov ntsiab lus carbon tsawg dua 0.25% muaj qhov qis qis tom qab annealing, thiab yooj yim rau "ko" thaum txiav.Los ntawm normalizing kev kho mob, dawb ferrite yuav txo tau thiab flake pearlite tau.Ua kom lub hardness tuaj yeem txhim kho lub machinability ntawm cov hlau, ua rau lub neej ntawm cov cuab yeej thiab qhov ua tiav ntawm qhov chaw ua haujlwm.
• 2) Tshem tawm cov thermal ua tsis xws luag.Medium-carbon structural steel castings, forgings, dov qhov chaw thiab welded qhov chaw yog feem ntau ua rau overheating defects thiab banded lug xws li coarse nplej tom qab cua sov.Los ntawm kev kho kom zoo, cov txheej txheem tsis zoo no tuaj yeem raug tshem tawm, thiab lub hom phiaj ntawm cov nplej ua kom zoo, cov qauv zoo ib yam thiab tshem tawm ntawm kev ntxhov siab sab hauv tuaj yeem ua tiav.
• 3) Tshem tawm lub network carbides ntawm hypereutectoid steel, yooj yim spheroidizing annealing.Hypereutectoid steel yuav tsum tau spheroidized thiab annealed ua ntej quenching kom yooj yim machining thiab npaj cov qauv rau quenching.Txawm li cas los xij, thaum muaj cov carbides loj network hauv cov hlau hypereutectoid, cov nyhuv spheroidizing zoo yuav tsis ua tiav.Net carbide tuaj yeem raug tshem tawm los ntawm normalizing kev kho mob.
• 4) Txhim kho cov khoom siv kho tshuab ntawm cov khoom siv sib xws.Qee cov pa roj carbon steel thiab alloy steel qhov chaw uas muaj kev ntxhov siab me ntsis thiab kev ua haujlwm tsis tshua muaj qhov yuav tsum tau ua kom ua tiav qee yam kev ua haujlwm txhua yam, uas tuaj yeem hloov kho quenching thiab tempering raws li qhov kawg kev kho cua sov ntawm cov khoom.

Kev xaiv ntawm annealing thiab normalizing
Lub ntsiab sib txawv ntawm annealing thiab normalizing:
1. Cov cua txias ntawm normalizing yog me ntsis sai dua annealing, thiab cov degree ntawm undercooling ntau dua.
2. Cov qauv tau txais tom qab normalizing yog finer, thiab lub zog thiab hardness yog siab tshaj li ntawm annealing.Kev xaiv ntawm annealing thiab normalizing:

• Rau cov pa roj carbon tsawg nrog cov ntsiab lus carbon <0.25%, normalizing feem ntau yog siv es tsis txhob annealing.Vim tias qhov txias txias tuaj yeem tiv thaiv cov hlau tsis tshua muaj los ntawm precipitating dawb tertiary cementite raws li cov ciam teb, yog li txhim kho qhov txias deformation kev ua tau zoo ntawm cov khoom stamping;normalizing tuaj yeem txhim kho qhov hardness ntawm cov hlau thiab txiav kev ua haujlwm ntawm cov hlau tsis tshua muaj carbon;Hauv cov txheej txheem kev kho cua sov, normalizing tuaj yeem siv los kho cov nplej thiab txhim kho lub zog ntawm cov pa roj carbon tsawg.
• Cov pa roj carbon nruab nrab nrog cov ntsiab lus carbon ntawm 0.25 thiab 0.5% kuj tuaj yeem ua kom zoo li qub tsis yog annealing.Txawm hais tias lub hardness ntawm nruab nrab carbon steel ze rau lub sab sauv txwv ntawm cov ntsiab lus carbon yog siab dua tom qab normalizing, nws tseem yuav raug txiav thiab tus nqi ntawm normalizing qis thiab siab productivity.
• Hlau nrog cov ntsiab lus carbon ntawm 0.5 thiab 0.75%, vim yog cov ntsiab lus carbon siab, qhov hardness tom qab normalizing yog siab dua li ntawm annealing, thiab nws nyuaj rau txiav.Yog li ntawd, tag nrho annealing feem ntau yog siv los txo cov hardness thiab txhim kho kev txiav.Kev ua tau zoo.
• Cov pa roj carbon siab lossis cov cuab yeej hlau nrog cov ntsiab lus carbon> 0.75% feem ntau siv spheroidizing annealing raws li kev kho cua sov ua ntej.Yog hais tias muaj ib tug network ntawm cov cementite theem nrab, nws yuav tsum tau normalized ua ntej.

Source: Mechanical professional literature.

Editor: Ali