Lub tshuab nqus tsev kub kho cov yam ntxwv

Aug 24, 2022

Hauv lub tshuab nqus tsev siab, nws muaj cov yam ntxwv hauv qab no:

Cov tshuaj ua haujlwm ntawm lub tshuab nqus tsev siab yog qhov tsawg heev. Thaum lub tshuab nqus tsev kho cua sov, cov tshuaj tiv thaiv uas tshwm sim ntawm qhov sib cuam tshuam ntawm cov roj theem thiab cov khoom siv theem, xws li oxidation, txo, decarbonization, thiab carburization, yuav tsis ua raws li qhov lawv muaj kev cuam tshuam.;

Lub tshuab nqus tsev siab ua kom lub ntim ntawm cov pa nrawm nrawm, uas tuaj yeem ua rau cov hlau lossis hlau tso tawm cov pa yaj lossis cov hlau oxide decompose. Nws yog qhov tseeb vim yog cov yam ntxwv ntawm lub tshuab nqus tsev siab uas nyob rau hauv lub tshuab nqus tsev siab, ib feem ntawm cov pa oxygen tsawg heev thiab cov nyhuv oxidation yog suppressed. Yog li ntawd, txhawm rau ua tiav lub hom phiaj ntawm kev tsis muaj oxidation, ib feem ntawm lub siab ntawm cov pa oxygen yuav tsum qis dua lub siab decomposition ntawm oxide.

Kev kho cua sov ci yog txoj kev kho cua sov uas tuaj yeem tiv thaiv oxidation cov tshuaj tiv thaiv ntawm cov hlau ua haujlwm thaum kho cua sov thiab tseem tau txais cov hlau ci ntsa iab. Kev kho cua sov kuj tseem tuaj yeem nqa tawm hauv qhov chaw tiv thaiv thiab inert gases xws li argon, helium thiab nitrogen, uas tuaj yeem ua tiav lub hom phiaj thiab kev xav tau ntawm kev tiv thaiv oxidation.Nqus cua sov kho tuaj yeem ua tiav tag nrho cov ntaub ntawv hlau kom tswj tau qhov qub nto, qhov tseeb qhov tseeb thiab qhov yuav tsum tau ua. Rau cov khoom ua haujlwm uas yuav tsum tau ua hauv av dua, cov txheej txheem ua ntej kev kho cua sov tuaj yeem txo qis heev, thiab cov txheej txheem ntxuav saum npoo (xws li pickling, sandblasting, tua blasting, thiab lwm yam) raug tshem tawm. Yog li ntawd, kev kho cua sov ntawm lub tshuab nqus tsev yog txoj kev pheej hmoo tshaj plaws thiab kev kho cua sov zoo tshaj plaws "atmosphere". Nws cov khoom siv hauv kev kho cua sov tau mus txog ntau dua 20 feem pua, tshwj xeeb tshaj yog nyob rau hauv aviation, aerospace, electronics Cheebtsam, textiles, tooling thiab lwm yam kev lag luam. Nws tau siv dav.

Cov nyhuv degassing (degassing) ntawm lub tshuab nqus tsev Cov nyhuv degassing ntawm lub tshuab nqus tsev yog raws li nram no.Metal degassing tuaj yeem txhim kho cov yas thiab lub zog ntawm cov hlau. Nyob rau hauv lub tshuab nqus tsev cua sov, ib tug npaum li cas ntawm cov roj (hydrogen, oxygen, nitrogen, thiab lwm yam) yaj nyob rau hauv lub hlau workpiece yuav overflow thiab degass los ntawm cov hlau nto, uas yog conducive rau kev txhim kho cov yas thiab lub zog ntawm lub workpiece. Qhov siab dua qhov kub, qhov hnyav dua qhov kev txav ntawm molecular, uas yog qhov tsim nyog rau kev txhawb nqa lub diffusion ntawm cov pa yaj hauv cov hlau mus rau saum npoo, kom cov qib ntawm lub tshuab nqus tsev yog nce, thiab qhov qis ntawm huab cua siab, nws yog conducive. mus rau lub overflow ntawm cov roj diffused ntawm cov hlau nto.

Nyob rau hauv cov txheej txheem smelting ntawm cov ntaub ntawv hlau, kua hlau nqus H2, O2, N2, CO thiab lwm yam gases. Muab rau hauv tus account tias cov solubility ntawm cov hlau mus rau saum toj no gases nce nrog qhov kub thiab txias, thaum cov kua hlau yog txias rau hauv steel ingots, solubility ntawm cov roj nyob rau hauv cov hlau yuav txo, tab sis vim lub txias ceev yog ceev heev, cov roj tsis tuaj yeem dhau los ua tiav (tso tawm), tab sis tseem nyob hauv cov khoom siv hlau, ua rau muaj qhov tsis xws luag xws li cov pores thiab cov pob dawb (tsim los ntawm H2) lossis cov khoom tawg hauv cov hlau hauv lub xeev atomic thiab ionic.

Tsis tas li ntawd, nyob rau hauv cov txheej txheem thermal ua ntawm hlau forging, kev kho cua sov, pickling, brazing, thiab lwm yam, roj yuav inevitably reabsorbed. Nyob rau lub sijhawm no, qhov kev tiv thaiv, kub conduction, magnetization, hardness, yield point, lub zog txwv, elongation, cross-section shrinkage, cuam tshuam toughness, tawg toughness thiab lwm yam khoom thiab lub cev ntawm cov hlau raug cuam tshuam, yog li tswj cov roj cov ntsiab lus. raw cov ntaub ntawv nyob rau hauv cov txheej txheem metallurgical, tab sis kuj sim tshem tawm cov roj absorbed hauv cov txheej txheem thermal, thiab lwm yam, los yog los ntawm kev txhim kho cov txheej txheem ntws los tiv thaiv cov pa nqus.

Lub diffusion ceev ntawm cov roj molecules nyob rau hauv cov khoom theem feem ntau txiav txim siab ceev ntawm degassing. Qhov laj thawj yog vim li cas lub tshuab nqus tsev degassing tuaj yeem tshem tawm cov roj hauv cov hlau yog tias cov roj hauv cov hlau tuaj yeem raug tshem tawm nyob rau hauv qhov tsis zoo siab, yog li lub xeev ntawm lub tshuab nqus tsev nyob rau hauv lub cub tawg cuam tshuam qhov ceev thiab cov nyhuv ntawm lub tshuab nqus tsev degassing.Lwm yam uas txiav txim siab degassing. cov nyhuv yog qhov kub thiab txias hauv qhov cub. Qhov siab dua qhov kub, qhov zoo dua cov nyhuv degassing.Qhov thib peb yog lub sijhawm. Lub sij hawm degassing ntev dua, qhov zoo dua cov nyhuv degassing.Nyob rau hauv tus account lub cuam tshuam ntawm yam xws li grain thickening thiab hlau theem hloov, qhov kub tsis tuaj yeem nce siab dhau. Rau cov ntaub ntawv hlau nrog cov theem hloov xws li steel, lub tshuab nqus tsev degassing ntawm qhov kub thiab txias ze ntawm theem hloov pauv tau zoo tshaj plaws. Yog vim li cas yog tias cov khoom siv hlau txo cov dej solubility ntawm cov pa thaum lub sij hawm hloov pauv los yog ua rau kev tsiv teb tsaws ntawm cov roj atoms vim kev hloov cov lattice thaum lub sij hawm hloov pauv.

Piv nrog rau kev kho cua sov, cov khoom siv kho tshuab (tshwj xeeb yog plasticity thiab toughness) ntawm cov khoom siv hlau ua haujlwm tom qab lub tshuab nqus tsev kho cua sov tau nce ntau. Yog vim li cas yog tias lub tshuab nqus tsev kho cua sov muaj cov nyhuv degassing zoo.Surface purification thiab degreasing yog siv los ua kom sov lub workpiece hauv lub tshuab nqus tsev. Cov oxide zaj duab xis, me ntsis xeb, nitrides, hydrides, thiab lwm yam nyob rau saum npoo yog txo, decomposed los yog evaporated thiab ploj, kom cov hlau tau ib tug du nto. Qhov no yog ib tug feature ntawm lub tshuab nqus tsev kub kho.

Cov tshuaj tiv thaiv oxidation ntawm cov hlau yog cov tshuaj tiv thaiv rov qab. Thaum cov hlau yog rhuab, txawm tias nws tsim cov tshuaj tiv thaiv oxidation los yog cov tshuaj tiv thaiv oxide decomposition nyob ntawm kev sib raug zoo ntawm ib feem ntawm cov pa oxygen nyob rau hauv cov cua kub cua thiab lub decomposition siab ntawm oxide.

Lub siab decomposition ntawm oxygen yog ib feem ntawm cov pa oxygen uas tsim tom qab decomposition ntawm oxides mus txog qhov sib npaug. Yog hais tias qhov decomposition siab ntawm oxygen ntau dua qhov siab ntawm cov pa oxygen, cov oxide decomposes thiab cov pa oxygen tsim tawm. Dab tsi yog sab laug yog qhov huv huv ntawm cov hlau, uas ua tiav cov nyhuv ntawm purifying cov hlau nto.Muaj tsawg heev cov pa oxygen nyob rau hauv lub tshuab nqus tsev, thiab ib nrab siab ntawm oxygen yog tsawg heev. Qhov siab dua ntawm lub tshuab nqus tsev, qhov qis dua ib feem ntawm cov pa oxygen, uas yog qis dua qhov decomposition siab ntawm oxide. Cov tshuaj tiv thaiv tau mus rau sab xis, yog li lub tshuab nqus tsev muab cov txheej txheem decomposition ntawm cov hlau oxide thaum rhuab.

Nyob rau hauv tas li ntawd, nyob rau hauv lub premise tias cov pa ib feem ntawm lub siab nyob rau hauv lub cub tawg yog tsawg heev, hlau oxides yuav decomposed rau hauv suboxides, uas yog yooj yim sublimated thiab volatilized nyob rau hauv lub tshuab nqus tsev cua sov. Cov khoom uas adheres rau saum npoo ntawm lub workpiece yog cov roj stains. , thiab lwm yam, uas yog carbon, hydrogen, thiab oxygen compounds. Lub vapor siab yog siab. Lawv yooj yim volatile los yog decompose thaum lub sij hawm lub tshuab nqus tsev cua sov txheej txheem thiab yog pumped tawm los ntawm lub tshuab nqus tsev twj tso kua mis kom huv si saum npoo ntawm lub workpiece. nyhuv.

Nws yuav tsum tau muab sau tseg tias thaum lub oxide ntawm cov hlau nto yog rhuab nyob rau hauv lub nqus tsev vacuum, nws kuj yuav reacts nrog diffusion los ntawm sab hauv ntawm cov khoom hlau mus rau H2 thiab C, txo cov oxide ntawm cov hlau nto. ntawm oxides, nws kuj yog nrog los ntawm kev tshem tawm cov organic tshuaj xws li roj thiab rog. Ntawd yog, tsis muaj kev tu tshwj xeeb kom tshem tawm cov khoom siv organic rau ntawm qhov chaw, qhov chaw ntawm lub workpiece tuaj yeem muaj qhov ci ntsa iab. Yog vim li cas yog tias cov roj thiab cov roj nplua nyeem yog aliphatic thiab yog cov sib txuas ntawm carbon, hydrogen thiab oxygen. Lub decomposition siab yog siab, yog li nws yog ib qho yooj yim rau decompose rau hauv hydrogen, dej vapor, carbon dioxide thiab lwm yam gases thaum rhuab nyob rau hauv lub nqus tsev vacuum, thiab ces pumped tawm los ntawm lub tshuab nqus tsev twj tso kua mis, nws yuav tsis muaj cov tshuaj tiv thaiv ntawm qhov chaw. ntawm qhov kub thiab txias, thiab qhov tsis-oxidizing thiab tsis-corrosive huv si tuaj yeem tau txais. Cov nyhuv purification ntawm lub tshuab nqus tsev ua kom cov hlau ntog ua haujlwm thiab yog qhov zoo rau kev nqus ntawm C, N, Cr, Si thiab lwm yam atoms accelerates tus nqi ntawm carburizing, nitriding, thiab nitrogen-carbon co-infiltration, thiab infiltration txheej yog ntau dua. khaub ncaws.

evaporation ntawm lub tshuab nqus tsev Thaum lub workpiece yog rhuab nyob rau hauv lub tshuab nqus tsev rauv, cov dej noo nyob rau hauv lub cub tawg thiab nitrogen, oxygen, thiab carbon monoxide nyob rau hauv cov huab cua yuav evaporated thiab dissipated ntawm tsawg kub. Tshaj li 800 degree, hydrogen, nitrogen, thiab oxide decomposition gases yuav raug tso tawm ntawm qhov chaw ntawm lub workpiece kom tiav cov nyhuv degassing, thiab cov evaporation tsim los ntawm thermal decomposition thiab khiav tawm ua rau cov hlau nto ci. Qhov no yog tus yam ntxwv ntawm kev kho cua sov ntawm lub tshuab nqus tsev. Lub tshuab nqus tsev txheej txheej txheem siv lub hauv paus ntsiab lus no los ua cov iav coated muab tso rau hauv kev lag luam hauv xyoo 1990s.

Lwm feature ntawm lub tshuab nqus tsev kho cua sov yog evaporation ntawm hlau nto ntsiab. Qhov no tau tshwm sim hauv kev kho cua sov ntawm high-chromium txias-ua haujlwm tuag hlau lossis chromium stainless hlau. Tom qab kev kho cua sov, cov khoom sib txuas ua ke, lossis nruab nrab ntawm cov khoom thiab cov khoom siv pob tawb (cov cuab yeej). Qhov saum npoo yog txiv kab ntxwv tev zoo li thiab ntxhib heev. Nyob rau tib lub sijhawm, qhov kev tiv thaiv corrosion yog txo qis. Qhov no yog qhov tsis zoo ntawm lub tshuab nqus tsev kub kho-hlau evaporation. Hais txog evaporation ntawm hlau, qhov sib npaug siab (vapor siab) ntawm chav ua yeeb yam ntawm cov hlau nto yog txawv. Yog tias qhov kub thiab txias, lub vapor siab yog siab, thiab evaporation ntawm cov khoom hlau yog loj; Yog hais tias qhov kub thiab txias yog tsawg, lub vapor Lub siab yog tsawg. Yog tias qhov kub thiab txias yog qhov tseeb, qhov vapor siab muaj qee qhov nqi. Thaum lub siab sab nraud tsawg dua li qhov ntsuas kub ntawm qhov ntsuas kub, cov hlau yuav evaporate (sublimate).Qhov me dua lub siab sab nraud, uas yog, lub tshuab nqus tsev siab dua, nws yooj yim dua evaporate, thiab zoo sib xws, qhov siab dua. lub vapor siab ntawm cov hlau, qhov yooj yim dua nws yog evaporate.

Nws tuaj yeem pom tias qhov vapor siab ntawm cov hlau sib txawv. Raws li cov khoom siv ntawm lub workpiece, tag nrho cov xim yuav tsum tau them rau qhov teeb meem evaporation, uas yog, raws li lub vapor siab thiab cua sov kub ntawm cov alloying ntsiab ntawm cov kho workpiece thaum tshav kub kub kho, qhov tsim nyog degree ntawm nqus tsev vacuum yuav tsum tau xaiv kom tsim nyog. los tiv thaiv cov evaporation ntawm qhov chaw alloying ntsiab.

Feem ntau siv cov khoom hauv cov hlau xws li Mn, Ni, Co thiab Cr, nrog rau cov khoom xws li Zn, Pb thiab Cu, uas yog cov khoom tseem ceeb ntawm cov hlau tsis muaj hlau, muaj lub siab vapor siab. Thaum rhuab hauv lub tshuab nqus tsev, nws yog ib qho yooj yim los tsim lub tshuab nqus tsev vacuum thiab ua rau lub workpiece (los yog tooling) lo rau ib leeg.Qhov tseeb, muaj qee qhov kev sib txuas ntawm vapor siab thiab cua sov. Ntev npaum li lub tshuab nqus tsev kawm tau raug xaiv kom tsim nyog, evaporation ntawm alloying ntsiab tuaj yeem tiv thaiv.

Tsis tas li ntawd, thaum lub tshuab nqus tsev cua sov, cov khoom siv hlau tuaj yeem txiav txim siab, thiab cov roj purity siab inert (uas yog, thim rov qab inflation xws li high-purity nitrogen, high-purity argon, thiab lwm yam) tuaj yeem qhia tau ntawm qhov kub thiab txias. los kho cov qib ntawm lub tshuab nqus tsev nyob rau hauv lub cub tawg, thiab lub tshuab nqus tsev cua sov yuav siv tau los tiv thaiv cov evaporation ntawm alloying ntsiab nyob rau saum npoo ntawm lub workpiece. Qhov kev ntsuas no ua tau zoo dua rau cov cuab yeej siv siab ceev, cov hlau alloy thiab lwm yam khoom siv.