Kev kho cua sov ntawm carbon steel rau rooj vagvalveraw khoom
Feem ntau ntawm lub cev lub cev, ib leeg ntws valve thiab lub rooj vag valve (piston valve) saib ntau txoj hauv kev, yog li kev siv dav dav ntawm casting qhov chaw. Tsuas yog qee qhov caliber li qub los yog lub rooj vag li qub nrog cov qauv kev ua haujlwm tshwj xeeb siv cov cam khwb cia hlau. Cov pa roj carbon steel tuaj yeem siv rau cov khoom tsis muaj corrosive, hauv qee qhov tshwj xeeb xws li nyob rau hauv qee qhov kub thiab txias, ib puag ncig tus nqi concentration, tuaj yeem siv rau qee yam corrosive. Muaj qhov kub thiab txias -29 ~ 425 ℃ ..
Feem ntau ntawm lub cev lub cev, ib leeg ntws valve thiab lub rooj vag valve (piston valve) saib ntau txoj hauv kev, yog li kev siv dav dav ntawm casting qhov chaw. Tsuas yog qee qhov caliber li qub los yog lub rooj vag li qub nrog cov qauv kev ua haujlwm tshwj xeeb siv cov cam khwb cia hlau.
Cov pa roj carbon steel tuaj yeem siv rau cov khoom tsis muaj corrosive, hauv qee qhov tshwj xeeb xws li nyob rau hauv qee qhov kub thiab txias, ib puag ncig tus nqi concentration, tuaj yeem siv rau qee yam corrosive. 1, tus qauv kev siv ntawm carbon cam khwb cia hlau qhov chaw siv nyob rau hauv peb lub teb chaws yog GB12229 - 89 "Universal valve, Technical standard of carbon steel casting parts", cov khoom hom yog WCA, WCB, WCC. Tus txheej txheem yog ua raws li cov khoom siv txawv teb chaws kuaj lub koom haum tus qauv ASTMA216-77 "high temperature fusible carbon steel Castings standard specification". Tus qauv tau hloov kho tsawg kawg yog ob zaug, tab sis kuv tus GB12229-89 tseem siv tau, thiab cov ntawv tshiab uas kuv pom nyob rau theem tam sim no yog Astma216-2001. Nws txawv ntawm Astma 216-77 (uas yog, los ntawm GB12229-89) nyob rau hauv peb txoj kev.
A: Cov kev cai xyoo 2001 tau ntxiv qhov yuav tsum tau ua rau WCB steel, uas yog, rau txhua txhua 0.01% txo tus nqi ntawm cov pa roj carbon ntau, qhov loj magnesium txwv tus nqi tuaj yeem nce los ntawm 0.04% mus txog rau qhov siab tshaj plaws yog 1.28%.
B: Lub sundries Cu ntawm WCA, WCB thiab WCC qauv: 0.50% hauv 77, kho rau 0.30% xyoo 2001; Cr: 0.40% hauv 77 thiab 0.50% xyoo 2001; Mo: Nws yog 0.25% hauv '77 thiab 0.20% hauv 2001.
C: Cov khoom seem synthesis yuav tsum tsawg dua lossis sib npaug li 1.0%. Xyoo 2001, thaum muaj cov qauv sib npaug ntawm cov pa roj carbon monoxide, cov kab lus no tsis haum, thiab qhov siab tshaj plaws carbon sib npaug ntawm peb tus qauv yuav tsum yog 0.5 thiab nws cov qauv sib npaug ntawm cov pa roj carbon sib npaug.
Cov teeb meem tshwm sim: A: Kev tsim nyog casting qhov chaw yuav tsum tsim nyog hauv cov tshuaj lom neeg muaj pes tsawg leeg, lub cev muaj zog, thiab ua tau raws li qhov yuav tsum tau ua, tshwj xeeb tshaj yog cov khoom seem ntawm cov khoom siv, txwv tsis pub ua rau lub weldability. B: Cov tshuaj lom neeg muaj pes tsawg leeg tau teev tseg hauv cov cai tseem yog qhov siab tshaj plaws. Txhawm rau kom tau txais kev sib txuas zoo thiab ua tiav cov khoom siv lub cev xav tau hauv cov txheej txheem tsim khoom, nws yog ib qho tsim nyog yuav tsum tsim kom muaj cov qauv kev tswj hwm sab hauv ntawm cov khoom thiab ua tiav cov kev kho cua sov kom raug ntawm cov khoom casting thiab cov pas ntsuas. Txwv tsis pub, kev tsim thiab tsim cov khoom tsis tsim nyog casting. Piv txwv li, WCB steel carbon cov ntsiab lus tus qauv ≤0.3%, yog hais tias lub smelter tawm WCB steel cov ntsiab lus ntawm 0.1% los yog qis dua los ntawm cov muaj pes tsawg leeg kom pom yog tsim nyog, tab sis lub cev kev ua tau zoo tsis tau raws li qhov yuav tsum tau. Yog tias cov ntsiab lus carbon sib npaug li 0.3%, tab sis qhov weldability tsis zoo, kev tswj cov ntsiab lus carbon yog tsim nyog rau 0.25%. Xav ua "kev nkag thiab tawm," qee cov tub ua lag luam yuav qhia meej txog cov kev tswj hwm cov pa roj carbon monoxide.
C: Kub qeb ntawm carbon steel li qub
(a) JB/T5300 — 91 "Universal valve khoom" yuav tsum carbon steel valve muaj kub ntawm -30 ℃ to 450 ℃.
(b) SH3064-94 "petrochemical steel valve xaiv, tshuaj xyuas thiab kev lees paub" yuav tsum muaj cov pa roj carbon steel valve muaj qhov kub ntawm -20 ℃ to 425 ℃ (daim ntawv thov qis qis ntawm -20 ℃ yog yuav tsum tau koom ua ke nrog GB150 steel siab nkoj )
(c) ANSI 16·34 "flange thiab pob tw vuam kawg valve" ua haujlwm siab - ntsuas tus nqi tam sim no tus qauv yuav tsum tau WCB A105 (carbon steel) muaj qhov kub thiab txias xws li -29 ℃ to 425 ℃, tsis tuaj yeem siv siab tshaj 425 ℃ rau ntev. Cov pa roj carbon steel muaj graphitization nyiam ntawm li 425 ℃. Kev kho cua sov ntawm cov ntaub ntawv hlau yog ib qho ntawm cov txheej txheem tseem ceeb hauv kev tsim cov khoom siv tshuab. Piv nrog rau lwm cov txheej txheem tsim khoom, kev kho cua sov feem ntau tsis hloov cov duab thiab tag nrho cov ntsiab lus ntawm lub workpiece, tab sis los ntawm kev hloov lub sab hauv microstructure ntawm lub workpiece, los yog kho qhov muaj pes tsawg leeg ntawm lub workpiece nto, muab los yog txhim kho qhov Performance index ntawm lub workpiece. . Cov yam ntxwv yog los txhim kho qhov tseem ceeb tshaj plaws ntawm lub workpiece, txawm li cas los xij, qhov no feem ntau tsis pom rau tib neeg lub qhov muag.
Thaum tshav kub kub kho technology yam ntxwv:
Kev kho cua sov ntawm cov ntaub ntawv hlau yog ib qho ntawm cov txheej txheem tseem ceeb hauv kev tsim khoom siv tshuab. Piv nrog rau lwm cov txheej txheem tsim khoom, kev kho cua sov feem ntau tsis hloov cov duab thiab tag nrho cov ntsiab lus ntawm lub workpiece, tab sis los ntawm kev hloov lub sab hauv microstructure ntawm lub workpiece, los yog kho qhov muaj pes tsawg leeg ntawm lub workpiece nto, muab los yog txhim kho qhov Performance index ntawm lub workpiece. . Cov yam ntxwv yog los txhim kho qhov tseem ceeb tshaj plaws ntawm lub workpiece, txawm li cas los xij, qhov no feem ntau tsis pom rau tib neeg lub qhov muag.
- Khoom, raws li cua sov, rwb thaiv tsev kub, tub yees, hloov cov txheej txheem kom tau txais cov yam ntxwv ntawm kev ua haujlwm.
Nta: Tsuas yog qhov chaw ntawm lub workpiece tuaj yeem hloov pauv hauv SSDS, tsis muaj cov duab tshwj xeeb tuaj yeem hloov pauv
Lub Hom Phiaj: Txhawm rau txhim kho daim ntawv thov thiab kev ua haujlwm ntawm cov khoom siv raw
Yeej tag nrho cov txheej txheem: cua sov → tshav kub rwb thaiv tsev → tub yees
Qeb:
1 Kev kho cua sov
quench
Kev kho cua sov thiab quenching
2 Kev kho cua sov saum npoo
Induction hardening
Organic tshuaj kho cua sov
Theem hloov taw tes thaum cua sov thiab txias
Cov tshuaj uas tsim los ntawm kev sib cais ntawm ib qho ionic crystal C nyob rau hauv lub lattice tas li ntawm Fe (ib qho txhuas alloy theem nyob rau hauv uas cov tshuaj molecules tau muab tso rau hauv lub lattice tas li ntawm cov organic hnyav thaum tseem tshuav cov organic hnyav)
Metallographic (F) C yaj nyob rau hauv α-Fe ua rau void ionic crystals
Ib qho tsis muaj ionic crystal uas tshwm sim los ntawm kev tawg ntawm austenite (A) C hauv Y-Fe
Pearlite (FeC) Cov khoom siv hlau ua los ntawm Fe thiab C
Ferrite (P) metallographic qauv thiab pearlite tsim tshuaj (FFeC)
45 Hlau: thawj mechanism Metallographic qauv (F) ferrite (P)
General kev kho cua sov txheej txheem ntawm steel
General Parts manufacturing Technology:
Kev tsim thiab tsim cov wool embryos - kev npaj rau kev kho cua sov - kev kho tshuab - kev kho cua sov zaum kawg - kev kho tshuab tiav
Kev npaj rau kev kho cua sov: quenching; quenching, kev kho cua sov
** Kev kho cua sov kawg: kev kho cua sov; quenching
Kev hloov ntawm cov hlau thaum nws yog cua sov
Cov nyhuv ntawm cov txheej txheem cua sov: tau txais austenite
Austenite txheej txheem ntau lawm:
Subcooling ntawm muaj pes tsawg leeg - subcooling ntawm muaj pes tsawg leeg ntawm F / Fe3C theem interface
Lub zog qhov kev loj hlob - F → A lattice tas li reconstructs Fe3C melting thiab C → A kis
3 Residual Fe3C melting
Kev npaj ntawm cov txheej txheem ntau lawm austenite
Qhov cuam tshuam ntawm austenite grain loj
Austenite homogenization
P-eutectoid hlau: PF
Rau eutectoid steel: P Fe3CⅡ
Qhov cuam tshuam ntawm cov txheej txheem thermal rwb thaiv tsev ntws:
Tau txais cov austenite zoo ib yam, tshem tawm cov kev ntxhov siab thermal, txhawb kev sib kis
Cov yam ntxwv cuam tshuam rau austenite grain loj:
Cov cua kub kub ↑, tuav lub sij hawm ↑ → Ib cov nplej loj hlob sai
Cua sov ceev ↑ → Ib qho zoo siv lead ua
Cov pa roj carbon uas muaj ↑ → Ib qho zoo siv lead ua
Pib mechanism fineness → Ib crystal fineness
Kev hloov ntawm cov hlau thaum txias
Tsawg kub austenite: Tsis muaj qhov hloov pauv tsis ruaj khov austenite tshwm hauv qab A1.
Kev tsom xam ntawm eutectoid C nkhaus
Peb hom variation
Kev hloov pauv kub tsis tu ncua: P - hom hloov
Atmospheric siab variation tsam: Hom B variation
Ultra-low kub variation tsam: M hom variation
Ferrite hloov
Ferrite muaj pes tsawg leeg: tshuab sib tov ntawm F thiab Fe3C
Nyob rau hauv lub xeev drives, cov muaj pes tsawg leeg yog supercooled thiab kev loj hlob yog diffusion-hom hloov
3 Zoo:
thaiv
A1 ~ 650 ℃: ferrite P
650 ~ 600 ℃: Trostenite S (zoo P)
600 ~ 550 ℃ : Trotensite T (ultra fine P kuj hu ua trotensite)
Post lub sij hawm: Feb-11-2023
