Lub rooj vag valve raw khoom Valve lub cev cov ntaub ntawv Carbon steel rooj vag valve raw khoom steel annealing
Yuav siv tau rau cov khoom uas tsis yog-corrosive, nyob rau hauv tej yam tshwj xeeb tej yam kev mob xws li nyob rau hauv ib tug tej yam kub thiab txias, concentration tus nqi ib puag ncig, yuav siv tau rau ib co corrosive tshuaj. Muaj qhov kub thiab txias -29 ~ 425 ℃. Lub cev valve, ib leeg ntws valve thiab lub rooj vag valve (piston valve) saib ntau txoj hauv kev, yog li kev siv cov khoom siv casting. 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.
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
Yuav siv tau rau cov khoom uas tsis yog-corrosive, nyob rau hauv tej yam tshwj xeeb tej yam kev mob xws li nyob rau hauv ib tug tej yam kub thiab txias, concentration tus nqi ib puag ncig, yuav siv tau rau ib co corrosive tshuaj. Muaj qhov kub thiab txias -29 ~ 425 ℃
Carbon cam khwb cia steel qhov chaw
Tam sim no, tus qauv siv hauv peb lub teb chaws yog GB12229 - 89 "General valve, carbon steel casting Technical Conditions", cov khoom lag luam 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.
Q&A
A: Tsim nyog casting qhov chaw yuav tsum tsim nyog nyob rau hauv cov organic chemical muaj pes tsawg leeg, structural mechanical zog, thiab ua tau raws li qhov yuav tsum tau, tshwj xeeb tshaj yog cov residue element manipulation, txwv tsis pub nws yuav ua mob rau lub vuam kev ua tau zoo.
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 ua haujlwm vuam zoo thiab ua tiav cov txheej txheem kev siv tshuab, 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 txheej txheem kho cua sov kom raug rau cov khoom siv 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 carbon cov ntsiab lus ntawm 0.1% los yog qis dua los ntawm cov muaj pes tsawg leeg los saib yog tsim nyog, tab sis cov yam ntxwv mechanical zog tsis tau raws li qhov yuav tsum tau. Cov ntsiab lus carbon yog sib npaug rau 0.3% kuj tsim nyog tab sis vuam cov khoom
Tsis zoo, kev tswj cov pa roj carbon rau 0.25% yog qhov tsim nyog dua. 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: Cov qeb kub ntsig txog carbon steel li qub
(a) JB/T5300 — 91 "Universal valve cov ntaub ntawv" yuav tsum tau 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 ℃ (kev siv cov kev txwv qis rau -20 ℃ yog txhawm rau koom nrog GB150 steel lub cev muaj zog)
(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 zoo li graphitize ntawm li 425 ℃.
Lub rooj vag valve raw khoom ntawm steel annealing tiav annealing (recrystallization annealing): cov hlau qeeb cua sov rau Ac3 (hypoeutectoid steel) saum 30 ~ 50 ℃, kom lub sij hawm nruab nrab, ces qeeb lub tub yees tawm. Rau cov hlau ntau, raws li cov txheej txheem cua sov ntawm ferrite rau hauv martensite (rov qab hloov recrystallization) thiab cov txheej txheem tub yees ntxiv rau qhov thib ob hloov recrystallization, siv lead ua zoo, tuab txheej, cov qauv ntawm ferrite. Grey cam khwb cia hlau annealing: cov hlau yog rhuab mus rau ib tug kub ntawm 30 ~ 50 ℃ saum Ac1, thiab ces maj mam txias tawm.
1) Cov ntsiab lus: Kub cov khoom mus rau 30 ~ 50 ℃ siab tshaj qhov ntsuas kub tseem ceeb, rwb thaiv tsev kub rau lub sijhawm, thiab tom qab ntawd nrog rau lub tshuab cua txias. (Qhov kub tseem ceeb: qhov kub ntawm cov qauv sab hauv ntawm cov hlau hloov)
2) Lub Hom Phiaj: (1) Txo lub zog thiab txhim kho kev sib tsoo;
(2) Txhim kho cov nplej, txhim kho cov qauv thiab faib cov cementite hauv cov hlau, thiab nteg lub hauv paus rau cov txheej txheem kho cua sov zaum kawg;
(3) Tshem tawm cov kev ntxhov siab thermal, tshem tawm cov kev ntxhov siab vim los ntawm kev hloov pauv ntawm kev tsim khoom, kev sib tsoo los yog hluav taws xob vuam thiab cov seem thermal stress nyob rau hauv qhov casting, txo deformation thiab tsis txhob qhuav tawg;
(4) spherification ntawm cementite kom txo tau lub zog;
⑤ Txhim kho thiab tshem tawm txhua yam kev ua haujlwm tsis zoo uas tsim los ntawm steel forging, calcination thiab vuam ua haujlwm, kom tsis txhob ua rau me me dawb.
4) Hom: Hauv kev tsim khoom, txheej txheem annealing yog siv ntau heev. Raws li cov khoom ua haujlwm annealing cov nyhuv tsis zoo ib yam, muaj ntau ntau hom txheej txheem annealing, feem ntau siv yog ua tiav annealing, grey cam khwb cia hlau annealing, los yog rau hauv av kev nyuaj siab annealing.
(1) Ua kom tiav annealing (recrystallization annealing): cov hlau qeeb cua sov rau Ac3 (hypoeutectoid steel) saum 30 ~ 50 ℃, kom lub sij hawm nruab nrab, ces qeeb lub tub yees tawm. Rau cov hlau ntau, raws li cov txheej txheem cua sov ntawm ferrite rau hauv martensite (rov qab hloov recrystallization) thiab cov txheej txheem tub yees ntxiv rau qhov thib ob hloov recrystallization, siv lead ua zoo, tuab txheej, cov qauv ntawm ferrite.
② Grey cam khwb cia hlau annealing: cov hlau yog rhuab mus rau qhov kub ntawm 30 ~ 50 ℃ saum Ac1, thiab ces maj mam txias tawm. Cov qauv ferrite dhau los ua spheroidal thiab granular, thiab cov pa roj carbon tsawg thiab nruab nrab nrog cov qauv no muaj lub zog qis, muaj zog drilling peev xwm thiab muaj zog txias khoov muaj peev xwm. Rau cov hlau alloy, cov qauv no yog cov qauv pib zoo dua ua ntej kev kho cua sov. (Sample ncej CrWMn, qhia ncej Tenon GCr15)
Ua kom tiav annealing thiab isothermal annealing
Ua kom tiav annealing - cua sov rau Ac3 20 ~ 30 ℃, rwb thaiv tsev kub tom qab txias rauv - hais txog cua sov kom tiav austenization
Lub Hom Phiaj: Raws li kev ua kom zoo recrystallization nplua nplej, symmetrical qauv, txhim kho kev ua haujlwm
Daim ntawv thov: hypoeutecoid steel, qis carbon steel: txo lub zog, txhim kho kev ua haujlwm drilling. Lub koom haum: FP
Isothermal txheej txheem annealing - cua sov rau Ac3 (Ac1) 20 ~ 50 ℃,
Thermal rwb thaiv tsev yog ua raws li huab cua txias tom qab cov txheej txheem isothermal hauv Ar1: nrog rau kev sib xyaw ua ke kom yooj yim tswj
Daim ntawv thov: nruab nrab thiab ferritic stainless hlau
Lub koom haum: FP lossis Fe3C P
Grey cam khwb cia hlau annealing thiab kis annealing
Grey cam khwb cia hlau annealed - rhuab rau Ac1 20 ~ 30
Lub Hom Phiaj: Kom tau txais kheej kheej Fe3C, mos
Daim ntawv thov: eutectoid, eutectoid steel
Cov ntaub so ntswg: spherical P
Spread annealing - cua sov mus rau 100-200 degrees hauv qab cov kab khoom, lub sij hawm ntev thermal rwb thaiv tsev (10-15h) tom qab txias txias
Hom phiaj: symmetrical composition
Haum rau: stainless hlau castings
Microstructure: Coarse grain - tom qab kis tau cov annealing tag nrho los yog quenching - optimization
Destress annealing thiab ua hauj lwm hardening annealing
De-stress annealing - cua sov rau Ac1-100 ~ 200 ℃, rwb thaiv tsev kub tom qab lub cub tawg txias
Lub Hom Phiaj: Txhawm rau tshem tawm cov kev ntxhov siab thermal thiab txhim kho lub koom haum
Daim ntawv thov: txias kos qhov chaw, kho cua sov qhov chaw
Lub koom haum: Nws yuav tsis hloov
Ua hauj lwm hardening annealing - cua sov rau t thiab ces 150 ~ 250 ℃, rwb thaiv tsev kub tom qab cua txias
Lub Hom Phiaj: Txhawm rau txo lub zog thiab txhim kho plasticity
Daim ntawv thov: ua hauj lwm hardening khoom workpiece
Qauv: equiaxed grain
Ua haujlwm hardening kub: T re = T melting × 0.4 (kub)
quenching
Normalizing - cua sov rau Ac3 (Accm) 30 ~ 50 ℃, rwb thaiv tsev kub tom qab cua txias
Lub Hom Phiaj: Kho cov nplej, txhim kho kev ua haujlwm
Daim ntawv thov: siab carbon steel HB↑ → Txhim kho qhov txiav cov khoom ntawm carbon (aluminium alloy) steel refining grain symmetry lub koom haum (kub kho, kho cua sov ua ntej) hypereutectoid steel → ntshiab mesh qauv Fe3CⅡ, nteg lub hauv paus rau spheroidization kev kho mob ntawm qhov chaw nrog qis dua → Cov cuab yeej siv tshuab ua haujlwm tau zoo kawg nkaus kev kho cua sov txheej txheem.
Post lub sij hawm: Feb-11-2023
