Quenching yog txheej txheem kev kho cua sov tsim los ntxiv dag zog rau cov hlau los ntawm kev ua kom txias sai. quenching ntawm steel yog txheej txheem kev kho cua sov uas cov hlau tau rhuab mus rau qhov kub thiab txias ntawm Ac3 (sub-eutectic steel) los yog Ac1 (per-eutectic steel) los yog siab dua, tuav rau ib lub sij hawm rau austenitise tag nrho los yog ib feem ntawm cov hlau. steel, thiab tom qab ntawd txias sai dua qhov tseem ceeb ntawm qhov txias txias kom qis dua Ms (lossis isothermal ze Ms) kom ua tiav qhov kev hloov pauv martensitic (lossis bainitic).
Txheej txheem: cua sov, tuav, txias.
- Cua sov: cov hlau yog rhuab mus rau qhov tseem ceeb kub Ac3 (sub-eutectic steel) los yog Ac1 (over-eutectic steel) saum toj no.
- Tuav lub sijhawm: khaws ib lub sijhawm, kom tag nrho lossis ib feem ntawm cov hlau austenitising.
- Cua txias: ceev txias kom qis dua Ms ntawm qhov txias txias ntau dua li qhov tseem ceeb ntawm qhov txias txias rau martensitic lossis bainitic transformation.
Lub ntsiab lus ntawm quenching:yog supercooled austenite rau martensite los yog bainite transformation, kom tau martensite los yog bainite organisation.
Lub hom phiaj ntawm quenching:
(1) Txhawm rau txhim kho qhov rigidity, hardness, hnav tsis kam, qaug zog thiab toughness ntawm hlau, thiaj li ua tau raws li qhov sib txawv ntawm kev siv ntau yam khoom siv thiab cov cuab yeej;
(2) los ntawm Quenching kom tau raws li ib co tshwj xeeb steel ferromagnetism, corrosion kuj thiab lwm yam tshwj xeeb lub cev thiab tshuaj.
Quenching steel qhov chaw muaj cov yam ntxwv hauv qab no:
- Cov koom haum tsis sib npaug xws li martensite, bainite thiab residual austenite tau txais.
- Lub hav zoov ntawm kev ntxhov siab loj hauv.
- Cov khoom siv tshuab tsis tuaj yeem ua tau raws li qhov yuav tsum tau ua. Yog li ntawd, cov hlau tom qab quenching feem ntau yuav tsum tau mus los ntawm tempering kho.
Scope ntawm kev siv:Cov txheej txheem quenching yog feem ntau siv, xws li cov cuab yeej, ntsuas, pwm, bearings, springs thiab tsheb, tsheb laij teb, diesel xyaw, txiav tshuab cuab yeej, pneumatic cov cuab yeej, drilling machinery, ua liaj ua teb siv, roj av machinery, tshuaj machinery, textile machinery, aircraft thiab lwm qhov chaw yog siv cov txheej txheem quenching.
Quenching Media
Workpiece Quenching txias nruab nrab siv yog hu ua quenching txias nruab nrab (los yog quenching nruab nrab). Qhov zoo tshaj plaws quenching nruab nrab yuav tsum muaj qhov xwm txheej uas lub workpiece tuaj yeem quenched rau hauv martensite, tab sis tsis ua rau muaj kev ntxhov siab ntau dhau.
Feem ntau siv quenching nruab nrab yog dej, aqueous tov, ntxhia roj, molten ntsev, molten alkali thiab hais txog.
Dej
Dej yog qhov muaj peev xwm txias txias ntawm qhov nruab nrab quenching.
Qhov zoo: qhov dav dav, tus nqi qis, ruaj khov muaj pes tsawg leeg tsis yooj yim rau deteriorate.
Qhov tsis zoo: lub peev xwm txias tsis ruaj khov, yooj yim ua rau lub workpiece deformation lossis tawg. Nyob rau hauv C nkhaus ntawm 'qhov ntswg' cheeb tsam (500 ~ 600 degree los yog li ntawd), dej nyob rau hauv lub vapor zaj duab xis theem, txias yog tsis ceev txaus, yuav tsim ib tug 'qhov chaw mos'; thiab nyob rau hauv lub martensite transformation kub cheeb tsam (100 ~ 300 degree), dej nyob rau hauv lub boiling theem, lub txias yog ceev heev, yooj yim ua rau lub Martensite transformation tus nqi yog sai heev thiab tsim ib tug ntau ntawm kev ntxhov siab nyob rau hauv lub workpiece deformation los yog txawm tawg. Thaum cov dej kub nce, cov dej muaj roj ntau los yog dej sib xyaw nrog cov impurities insoluble (xws li roj, xab npum, av nkos, thiab lwm yam), yuav txo nws lub peev xwm txias.
Daim ntawv thov: Nws yog tsim rau quenching thiab txias ntawm cov pa roj carbon steel workpieces nrog me me cross-section loj thiab cov duab yooj yim.
Dej ntsev thiab dej alkaline
Ntxiv rau qhov tsim nyog cov ntsev thiab alkali nyob rau hauv dej, kom high-temperature workpiece rau hauv lub txias nruab nrab, nyob rau hauv lub chav zaj duab xis theem nag lossis daus ntawm ntsev thiab alkali crystals thiab tam sim ntawd tawg, lub chav zaj duab xis yog puas, nto ntawm lub workpiece oxidation. daim tawv nqaij kuj tau tawg, yog li koj tuaj yeem txhim kho qhov nruab nrab hauv qhov chaw siab-kub ntawm lub peev xwm txias, qhov tsis zoo yog qhov nruab nrab ntawm qhov corrosive qhov loj.
Daim ntawv thov: Feem ntau, qhov concentration ntawm brine yog 10 feem pua, thiab cov concentration ntawm aqueous caustic soda tov yog 10 mus rau 15 feem pua. Nws tuaj yeem siv los ua qhov nruab nrab quenching rau cov pa roj carbon steel thiab cov hlau tsis tshua muaj steel hlau workpieces, kev siv kub yuav tsum tsis pub tshaj 60 degree, quenching yuav tsum tau ntxuav nyob rau hauv lub sij hawm tom qab quenching thiab anti-xeb kho.
Roj
Cov cua txias nruab nrab feem ntau siv cov roj ntxhia (cov roj ntxhia), xws li cov roj cav, cov roj hloov pauv thiab cov roj diesel. Lub cev muaj zog roj feem ntau yog siv 10, 20, 30 lub cev muaj zog roj, qhov loj ntawm cov roj, qhov ntau dua qhov viscosity, qhov siab dua qhov flash point, qis dua qhov txias txias, kev siv qhov kub thiab txias nce ntxiv.
Txoj kev quenching
Ib leeg-kua quenching
Quenching yog ib qho kev ua haujlwm quenching uas cov khoom austenitic tau muab tso rau hauv qhov nruab nrab quenching thiab txias rau chav sov. Ib leeg-kua quenching media suav nrog dej, brine, dej alkaline, roj thiab tshwj xeeb tsim cov tshuaj tua kab mob.
Quenching martensitic qib quenching
Yog cov tshuaj austenitic thawj zaug rau hauv qhov kub thiab txias me ntsis siab dua los yog qis dua lub martensite taw tes ntawm cov hlau nyob rau hauv cov kua nruab nrab (ntsev da dej los yog alkaline da dej), kom tswj tau lub sij hawm tsim nyog, yuav tsum yog cov hlau qhov chaw ntawm sab hauv thiab sab nrauv txheej. ntawm qhov nruab nrab tau mus txog qhov kub thiab txias ntawm cov cua txias, thiaj li yuav tau txais lub koom haum martensite ntawm cov txheej txheem quenching, tseem hu ua quenching ntawm qib quenching.
Bainite isothermal quenching
Quenching yog austenitising ntawm steel qhov chaw, kom ceev ceev txias rau lub bainite transformation kub ntau yam (260 ~ 400 degree) isothermal tuav, kom lub austenite transformation rau bainite quenching txheej txheem, tej zaum kuj hu ua isothermal quenching, dav tuav lub sij hawm ntawm 30 ~ 60 min.
Composite Quenching
Lub workpiece yog txias txias rau hauv qab Ms kom tau 10% mus rau 20% martensite, thiab ces isothermal nyob rau hauv lub qis bainite kub cheeb tsam. Txoj kev ua kom txias no tuaj yeem ua rau ntu loj ntawm cov khoom ua haujlwm kom tau txais M + B koom haum. Lub martensite tsim thaum lub sij hawm ua ntej quenching txhawb lub bainite transformation, thiab lub martensite yog tempered thaum lub sij hawm isothermal tempering. Composite quenching yog siv rau alloy cuab yeej steel workpieces kom tsis txhob hom I temper brittleness thiab txo tus nqi ntawm residual austenite, piv txwv li cov nyiam deformation cracking.
