Kev Kho Mob Txias txhais li cas hauv Seamless Pipe Production
Hauv cov pa roj carbon thiab qis- alloy seamless yeeb nkab ntau lawm, "kev kho mob khaub thuas" npog cov haujlwm ua haujlwm ua haujlwm kub: tswj quenching los ntawm austenitising kub, tempering, thiab txias tiav cov kauj ruam xws li txias txias, txias pilgering thiab kev ntxhov siab. Lub hom phiaj yog ib qho kev sib xyaw ua ke ntawm lub zog, hardness thiab toughness uas kub dov ib leeg tsis tuaj yeem lav, vim tias cov yeeb nkab phab ntsa yuav tsum tau txias uniformly los ntawm nws cov tuab tuab.
Hauv kev xyaum zeb, lub sij hawm yog siv feem ntau mus rau theem quenching, qhov twg cov hlau yog reheated rau nws cov austenitising ntau thiab ces txias sai heev nyob rau hauv ib tug xaiv nruab nrab. Txias tus nqi tswj ntau npaum li cas martensite los yog bainite cov ntaub ntawv, thiab yog li ntawd lub hardness cov yeeb nkab yuav ncav cuag. Tempering, nqa tawm tam sim ntawd tom qab ntawd, coj ductility thiab cuam tshuam toughness rov qab mus rau qib tau txais thaum tuav lub zog tau txais thaum lub sijhawm quenching.
Quenching Media Piv
| Quenching nruab nrab | Kev siv txias txias | Hardness teb | Distortion thiab cracking txaus ntshai | Tej daim ntawv thov |
|---|---|---|---|---|
| Dej, nrog lossis tsis muaj kev ntxhov siab | Siab tshaj ntawm peb | Ntau tshaj li -quenched hardness | Qhov siab tshaj plaws, tshwj xeeb tshaj yog rau cov phab ntsa hnyav thiab cov ntu tsis sib xws | Cov pa roj carbon steel kav uas yuav tsum tau ua kom tag nrho hardening |
| Roj | Nruab nrab, qeeb dua dej | Tsawg dua dej tab sis zoo ib yam | Txo, uas txo qhov kev pheej hmoo ntawm quench cracking | Chromium-molybdenum thiab lwm cov yeeb nkab hlau ua rau tawg |
| Molten ntsev los yog polymer da dej | Adjustable, feem ntau ntawm dej thiab roj | Tswj tau thiab rov ua tau | Tsawg, vim tias qhov txias txias yog qhov sib xws | Cov qib tshwj xeeb uas qhov ntsuas qhov ntsuas tseem ceeb tshaj qhov siab tshaj plaws |
Dej quenching yog txoj hauv kev classic: cov yeeb nkab tau txias sai sai kom nce hardness, thiab tempering tom qab ntawd rov qab ua ib feem ntawm qhov toughness uas cov cua txias sai sai tshem tawm. quenching yuav ua raws li ncaj qha tom qab cua sov theem los yog ua ntej tempering nyob rau hauv ib tug tas mus li kab, tab sis qhov kub thiab txias, lub sij hawm soaking thiab hloov lub sij hawm yuav tsum tau teem rau qhov tshwj xeeb carbon steel qib, yeeb nkab loj thiab daim ntawv thov.
Roj quenching txias qeeb dua, uas txo cov brittleness thaum tseem ua tau zoo hardness. Ntsev thiab polymer da dej yog siv qhov chaw siab tab sis tswj tau qhov txias txias yog xav tau yam tsis muaj thermal poob siab ntawm dej; lawv kuj txo cov kev ntxhov siab sab hauv thiab deformation. Vim tias cov ntsev molten yog qhov kub thiab txias, cov txheej txheem kev nyab xeeb yog qhov tseem ceeb.
Quenching thiab Tempering Parameters uas tswj qhov tshwm sim
Austenitising kub thiab soak lub sij hawm:yuav tsum tau yaj tag nrho cov pa roj carbon thiab alloying ntsiab yam tsis muaj grain coarsening, uas yuav txo tau toughness.
Hloov sijhawm:lub sijhawm nruab nrab ntawm kev tawm hauv lub cub tawg thiab nkag mus rau hauv lub quench yuav tsum luv txaus kom tsis txhob muaj kev hloov pauv ib nrab ua ntej pib txias.
Cooling rate thiab agitation:txiav txim los ntawm -wall hardness profile; Tus nqi tsis txaus tawm cov mos ferrite lossis pearlite bands.
Tempering kub thiab sijhawm:lub ntsiab lever rau trading zog tiv thaiv ductility; tempering siab dua muab lub zog qis dua thiab muaj txiaj ntsig zoo dua.
Ntu thickness:Cov phab ntsa hnyav dua txias qeeb qeeb ntawm qhov chaw, yog li qhov ua tiav qhov tawv tawv ntog thaum phab ntsa thickness nce.
Daim ntawv thov thiab qib xaiv
Seamless kav dej rau siab - qhov kub thiab txias kev pab cuam feem ntau yog xa hauv qhov kub- tiav, thiab kev kho cua sov tsuas yog teev thaum daim ntawv thov xav tau. ASTM A106 yuav tsum tau txias- cov yeeb nkab kos los kho cua sov, thiab ASTM A333 qis- cov yeeb nkab kub yog muab rau normalized rau qhov tsis zoo ntawm qhov kub thiab txias. Alloy qib xws li ASTM A335 chromium- cov kav dej molybdenum yog ib txwm muab cov khoom qub thiab tempered lossis quenched thiab tempered nyob ntawm qib. Kab yeeb nkab rau API 5L yog muab rau hauv kev xa khoom xws li - dov, normalised, lossis quenched thiab tempered, thiab cov kev xaiv yuav tsum tau teev nyob rau hauv kev txiav txim.
Rau cov kev pabcuam ntub dej, kev tswj xyuas qhov nyuaj dhau los ua qhov tsim nyog yuav tsum tau ua ntau dua li qhov kev nyiam ua haujlwm: NACE MR0175 / ISO 15156 txwv cov pa roj carbon thiab qis- alloy steels rau qhov siab tshaj plaws hardness ntawm 22 HRC kom txo tau qhov kev pheej hmoo ntawm sulfide kev nyuaj siab tawg. quenching thiab tempering yog txoj hauv kev zoo tshaj plaws kom tau raws li qhov kev txwv ntawd thaum ua kom lub zog siab txaus rau kev tsim siab.
Cov Ntsiab Tshuaj Ntsuam Xyuas thiab Cov Pitfalls
Kev soj ntsuam Hardness ntawm lub cev yeeb nkab, tshem tawm ntawm qhov kawg, raws li cov qauv qauv pom zoo nrog tus neeg yuav khoom.
Tensile thiab, qhov twg tau teev tseg, Charpy cuam tshuam kev kuaj ntawm cov qauv coj mus rau hauv txoj kab ntev.
Kev ntsuam xyuas microstructure kom paub meej tias lub tempered martensite los yog tempered bainite qauv, tsis muaj dawb ferrite bands.
Kev tshuaj xyuas saum npoo rau quench cov kab nrib pleb, uas yuav luag ib txwm tshwm sim los ntawm ntau tshaj - nruab nrab hnyav, tsis zoo agitation lossis qeeb tempering.
Kev tswj ntawm decarburisation thiab nplai thaum rov ua kom sov, vim ob qho tib si cuam tshuam rau qhov kawg ntawm qhov tawv tawv.
FAQ
Q: Puas yog kev kho mob khaub thuas zoo ib yam li kev ua haujlwm txias?
Tsis yog. Kev ua haujlwm txias yog hais txog kev ua haujlwm tsis zoo xws li kev kos duab txias lossis txias pilgering, thaum kho txias hauv cov yeeb nkab zeb feem ntau txhais tau tias quenching thiab tempering. Qhov ob feem ntau sib xyaw ua ke: ib lub yeeb nkab yuav txias txias rau qhov loj, tom qab ntawd kho cua sov thiab txo kev ntxhov siab.
Q: Qhov twg quenching nruab nrab ua rau lub siab tshaj plaws hardness?
Dej, tshwj xeeb tshaj yog nrog kev ntxhov siab, ua kom txias sai tshaj plaws thiab yog li qhov siab tshaj plaws li -quenched hardness. Cov roj thiab ntsev da dej txias dua maj mam thiab ua kom qis dua tab sis muaj zog dua qub.
Q: Vim li cas tempering ib txwm ua tom qab quenching?
Raws li -quenched lug yog nyuaj tab sis nkig. Tempering txo cov kev ntxhov siab sab hauv, rov ua kom cov ductility thiab cuam tshuam toughness, thiab tso cai rau lub zog theem kom hloov mus rau qhov tshwj xeeb.
Q: Lub quench puas tuaj yeem ua tam sim tom qab kub dov?
Direct quenching yog ua tau thaum lub dov kub tseem nyob rau hauv lub austenitising ntau yam, tab sis nws xav tau nruj tswj ntawm qhov kub thiab txias thiab hloov lub sij hawm. Ntau lub mills nyiam qhov sib cais reheating rauv kom zoo dua rov ua dua.
Q: Puas yog kev kho mob khaub thuas puas txhim kho corrosion?
Tsuas yog indirect. Cov qauv tempered tsis zoo tshem tawm cov teebmeem galvanic ntawm banded lossis cais microstructures, tab sis ntev -lub sij hawm corrosion kuj nyob rau hauv kev pab cuam yog tswj los ntawm cov ntsiab lus alloy, ib puag ncig thiab kev tiv thaiv txheej los yog hauv ob sab phlu siv.
Q: Yuav ua li cas hardness txheeb xyuas ntawm cov yeeb nkab tiav?
Los ntawm kev ntsuas lub cev los yog lub rooj zaum nyuaj ntawm cov yeeb nkab lub cev, siv Brinell lossis Rockwell txoj hauv kev, nrog rau qhov chaw, tus naj npawb ntawm kev nyeem ntawv thiab kev lees paub txwv tau kho hauv qhov tshwj xeeb. Kub-tsim thiab txias- cov kav dej tau raug kuaj xyuas hauv qhov xwm txheej uas lawv tau muab.
Q: Yuav ua li cas yog tias tempering qeeb?
Ncua tempering tso cov yeeb nkab rau hauv ib qho kev ntxhov siab heev, nkig thiab ua rau muaj kev pheej hmoo ntawm kev tawg thaum tuav lossis ncaj. Tempering yuav tsum ua raws li quenching yam tsis muaj kev ncua sijhawm.
