Daim ntawv thov ntawm Ni- puag Alloy hauv Dissimilar Steel Vuam
1. Cov teeb meem tseem ceeb hauv cov txheej txheem vuam ntawm cov hlau tsis sib xws
Dissimilar steel welding, nyob rau hauv layman cov ntsiab lus, yog cov txheej txheem nyob rau hauv uas steel cov ntaub ntawv ntawm txawv cov ntaub ntawv yog melted ua ke los ntawm welding txoj kev los ua dissimilar steel welding. Muaj qhov sib txawv tseem ceeb ntawm cov welded pob qij txha ntawm cov hlau tsis sib xws thiab cov welded pob qij txha ntawm tib lub hlau, feem ntau yog vim qhov tsis sib xws ntawm cov hlau tso, cov cua sov cuam tshuam cheeb tsam thiab lub hauv paus hlau ntawm ob sab ntawm vuam. Thaum vuam sib txawv ntawm cov hlau tsis sib xws, vim qhov sib txawv ntawm cov khoom siv vuam xaiv thiab cov hlau hauv paus, nws yog ib qho tsim nyog los xam qhov muaj pes tsawg leeg, qauv thiab kev ua haujlwm ntawm cov hlau vuam. Thaum tshav kub kub conduction kub teb ntawm vuam arc; Microstructure thiab cov khoom ntawm welded sib koom; Weldability test thiab txheej txheem kev pom zoo kuaj; Cov cuab yeej siv rau siab -kev ua haujlwm vuam ntawm cov nkoj thiab sib xws high- siv tshuab vuam tshuab; Vuam txheej txheem ntawm ntau yam khoom siv hlau; Cov txheej txheem hlau vuam txheej txheem ntawm kev lag luam petrochemical, cov nqaj loj thiab kab ke, kev tsim cov nkoj siab, kev tsim hluav taws xob tawm sab nrauv thiab lub nkoj hull qauv yog tag nrho nyob rau hauv qhov sib txawv ntawm cov hlau vuam sib txawv. Cov hauv qab no yog kev soj ntsuam ntawm cov teeb meem uas muaj nyob rau hauv cov txheej txheem vuam ntawm cov hlau tsis sib xws.
1.1 Weld hlau dilution
Muaj qhov sib txawv ntawm qhov sib txawv ntawm cov hlau sib xyaw ntawm cov vuam seam thiab cov hlau nyob ib ncig ntawm lub vuam seam hauv vuam ntawm cov hlau tsis sib xws. Lub melting npaum li cas ntawm lub hauv paus hlau yog hais txog lub thickness ntawm lub hauv paus hlau, qhov loj thiab cov duab ntawm lub vuam seam, lub arc voltage, vuam txoj hauj lwm thiab vuam ceev. Thaum welding sib txawv steels, kev sib nrig sib dilution ntawm lub melting cheeb tsam ntawm lub hauv paus hlau thiab deposited hlau yuav hloov, uas ua rau cov kev hloov ntawm cov tshuaj muaj pes tsawg leeg ntawm lub welded sib koom. Cov tshuaj lom neeg muaj pes tsawg leeg ntawm kev sib koom ua ke tsis sib xws, uas ua rau muaj kev hloov pauv ntawm cov qauv hlau ntawm cov welded seam, yog li cuam tshuam rau cov vuam sib txuas. Yog tias cov nickel-raws li alloy yog siv los ua cov txheej txheem kev sib cais hauv cov txheej txheem vuam, nws tuaj yeem tiv thaiv kev hloov pauv ntawm cov hlau tshuaj muaj pes tsawg leeg, tswj qhov kub thiab txias nyob ib ncig ntawm lub vuam, thiab zam lub dilution ntawm vuam hlau.
1.2 Residual stress of joint
Qhov sib txawv ntawm cov qauv hlau sib txawv ntawm cov hlau tsis sib xws ua rau qhov sib txawv ntawm cov kab sib txawv ntawm ob, thiab tib lub sijhawm, muaj qhov sib txawv ntawm cov yas thiab thermal conductivity nyob rau hauv qhov sib koom ua ke, uas yuav ua rau qhov txawv txav ntawm qhov kub thiab txias thaum lub sij hawm vuam, ua rau muaj kev ntxhov siab nyob rau hauv qhov sib koom ua ke, cuam tshuam rau kev ruaj ntseg ntawm txoj hauj lwm sib koom, thiab cuam tshuam rau qhov kev pab cuam lub neej.
1.3 Carbon tsiv teb tsaws
Filled hlau thiab molten puag hlau sib xyaw ntawm sab hauv thiab ntug ntawm lub pas dej molten, tab sis muaj qee qhov sib txawv ntawm qhov sib xyaw. Qhov chaw sib xyaw tsis tiav tshwm nyob rau ntawm thaj tsam weld, thiab txheej txheej decarburized tshwm rau ntawm ib sab ntawm cov hlau tsis sib xws, thiab txheej txheej carburized tshwm rau sab nraud, uas cuam tshuam rau plasticity thiab durability ntawm cov qauv weld. Cov ntsiab lus ntawm npib tsib xee hauv qhov vuam tuaj yeem cuam tshuam qhov tsim ntawm carbide los ntawm graphitization, thiaj li tsis txhob carbon migration thiab tsim ib txheej diffusion.
2. Kev daws teeb meem hauv cov txheej txheem vuam ntawm cov hlau tsis sib xws
Cov teeb meem uas feem ntau tshwm sim hauv cov txheej txheem vuam ntawm cov hlau tsis sib xws yog qhia saum toj no. Hauv kev tsim kho tiag tiag, yog tias muaj teeb meem nrog cov hlau tsis sib xws hauv cov txheej txheem vuam, nws yuav cuam tshuam rau tag nrho cov vuam thiab kev tsim kho, yog li nws yog ib qho tsim nyog yuav tsum tau kawm thiab daws cov teeb meem uas twb muaj lawm. Thawj qhov teeb meem uas yuav tsum tau them sai sai rau yog dilution ntawm weld hlau. Feem ntau, thaum vuam sib txawv ntawm cov hlau tsis sib xws, qhov sib txawv ntawm cov hlau alloy yuav txawv ntawm cov hlau nyob ib puag ncig, thiab nws yuav cuam tshuam los ntawm qee yam. Thaum lub vuam hlau yog diluted thaum lub sij hawm vuam, nws yog feem ntau deformation. Thaum lub sij hawm dilution txheej txheem, cov muaj pes tsawg leeg ntawm welded ib feem yuav hloov, thiab ua rau kev faib ntawm cov khoom no tsis sib xws, uas yuav ua rau lub microstructure ntawm cov hlau ntawm weld seam hloov, cuam tshuam rau tag nrho cov vuam. Yog li ntawd, daim ntawv thov ntawm Ni-raws li alloys nyob rau hauv cov txheej txheem vuam, raws li cov txheej txheem ntawm kev sib cais ntawm cov vuam seam thiab cov vuam sib txuas, tuaj yeem daws tau qhov teeb meem ntawm kev hloov pauv ntawm cov hlau chemical. Thiab qhov kub thiab txias nyob ib ncig ntawm lub vuam yuav raug tswj xyuas kom ntseeg tau tias cov hlau tsis yog diluted. Yog li ntawd, kev siv cov nickel-raws li alloys nyob rau hauv cov txheej txheem vuam ntawm cov hlau tsis sib xws yuav ua tau zoo kom tsis txhob muaj kev cuam tshuam ntawm cov hlau vuam thiab cov kev hloov hauv cov tshuaj muaj pes tsawg leeg.
Qhov teeb meem ntawm kev ntxhov siab nyob hauv cov pob qij txha welded kuj tseem yuav daws tau zoo. Vim tias muaj qhov sib txawv ntawm cov hlau hauv cov txheej txheem ntawm cov hlau tsis sib xws, cov coefficients ntawm ob lub coefficients hloov thiab muaj qhov sib txawv thaum vuam. Nyob rau hauv txoj kev no, qhov teeb meem ntawm qhov txawv txav ntawm lub voj voog thermal yuav tshwm sim hauv cov txheej txheem ua haujlwm tiag tiag, thiab yuav muaj qhov sib txawv ntawm cov thermal conductivity ntawm qhov sib koom ua ke thiab cov hlau, uas yuav ua rau muaj kev ntxhov siab nyob rau hauv qhov sib koom ua ke, uas yuav cuam tshuam rau cov txheej txheem vuam. Kev ruaj ntseg ntawm lub taub hau thiab kev pab cuam lub neej ntawm cov khoom siv welded kuj yuav muaj qee yam cuam tshuam. Yog li ntawd, tshem tawm qhov kev ntxhov siab ntawm qhov sib koom ua ke yuav ua rau muaj txiaj ntsig zoo rau kev ua haujlwm ntawm qhov welded thiab siv nickel-raws li alloys raws li cov khoom siv vuam tuaj yeem txhim kho qhov kev ua tau zoo ntawm cov hlau thiab kev sib koom ua ke. Lub thermal conductivity ntawm qhov sib koom ua ke, thiaj li yuav tsis muaj teeb meem nyob rau hauv lub thermal voj voog txuas thaum lub vuam txheej txheem. Thaum ua kom ntseeg tau qhov kev ntxhov siab ntawm qhov sib koom ua ke, nws kuj ua rau muaj kev txhim kho zoo dua rau kev ruaj ntseg ntawm tag nrho cov kev sib koom ua ke thiab kev ua haujlwm ntawm cov txheej txheem vuam. Yog li ntawd, nyob rau hauv tus txheej txheem ntawm cov hlau tsis sib xws, daim ntawv thov ntawm npib tsib xee-raws li alloys yuav daws tau qhov teeb meem ntawm residual kev nyuaj siab nyob rau hauv lub sib koom tes.
Nyob rau hauv tus txheej txheem ntawm dissimilar steel welding, qhov teeb meem ntawm carbon migration kuj yooj yim tshwm sim. Qhov laj thawj tseem ceeb ntawm cov teeb meem ntawm cov pa roj carbon monoxide yog melting nyob rau hauv lub zog ntawm cov hlau hauv thiab ib ncig ntawm lub pas dej ua ke, thiab cov khoom siv hlau thiab cov kua dej sib xyaw ua ke. Qhov no ua rau cov ntsiab lus carbon hauv cov pob qij txha sib txawv ntawm cov hlau tsis sib xws muaj qee qhov sib txawv, ua rau tsis tiav stitching ntawm tus ciam teb weld. Yog li ntawd, ib txheej decarburized thiab txheej carburized tshwm, thiab ob qhov no yuav muaj kev cuam tshuam rau cov qauv vuam. Kev siv cov nickel zoo-raws li alloys tuaj yeem ua rau muaj qhov tshwm sim ntawm cov pa roj carbon monoxide, ua lub luag haujlwm inhibitory hauv kev tsim cov carbides tsim los ntawm carbon migration, zam qhov tshwm sim ntawm decarburized txheej thiab carburized txheej tsim tom qab carbon tsiv teb tsaws, thiab muaj kev cuam tshuam tsis zoo rau tag nrho Cov qauv welded thiab ua kom zoo dua qub.
3. Dissimilar steel vuam txheej txheem
Cov hom austenitic stainless hlau thiab qis - alloy heat- cov hlau tsis muaj zog yog siv los ua cov hlau tsis sib xws rau kev ua haujlwm vuam. Hauv qis- alloy tshav kub- cov hlau tsis muaj zog, cov ntsiab lus ntawm chromium thiab molybdenum kuj siab heev. Nws yog ib qho tsim nyog los ua txoj haujlwm zoo ntawm kev kho cua sov tom qab vuam kom ruaj khov ntawm kev sib koom ua haujlwm thiab cov qauv, thiab kom tsis txhob muaj cua quenching. Txawm li cas los xij, kev kho cua sov tom qab vuam yog ib qho yooj yim uas yuav ua rau lub deterioration ntawm corrosion kuj ntawm austenitic stainless hlau, uas ua rau cov kab nrib pleb nyob rau hauv lub welded sib koom ua ke thiab cuam tshuam rau kev ruaj ntseg ntawm kev sib koom tes. Yog li ntawd, cov ntaub ntawv hlau uas muaj cov nickel thiab chromium siab tuaj yeem siv rau hauv cov txheej txheem vuam los tiv thaiv cov pa roj carbon dilution, tsis txhob dilution ntawm vuam hlau thiab kev sib koom ua ke, thiab xyuas kom meej vuam nyhuv.
Ua ntej tshaj plaws, siv electrode arc vuam los yog tungsten argon arc vuam rau saum npoo ntawm npib tsib xee -raws li cov khoom siv hlau sib cais ntawm cov hlau tsis sib xws. Tom qab dhau qhov kev tshuaj ntsuam xyuas, kev ua haujlwm kho cua sov yog ua kom tshem tawm cov kev ntxhov siab uas seem. Tom qab ntawd, vuam pas nrig arc vuam thiab phau ntawv argon tungsten arc vuam yog siv los vuam austenitic stainless hlau thiab qis- alloy tshav kub- resistant steel.
4. Vuam yam ntxwv thiab daim ntawv thov cuam tshuam ntawm nickel-raws li alloys
Lub vuam hlau ntawm nickel{0}}raws li alloy muaj ib qho kev sib xyaw ua ke, cov kua dej tsis zoo, thiab yog cov qauv austenitic. Thaum lub sij hawm vuam txheej txheem, qhov nkag mus yog ntiav, thiab me me pores thiab me me kub tawg yog nquag tshwm sim, uas cuam tshuam rau vuam. Yog li ntawd, ua ntej welding Nws yog ib qho tsim nyog yuav tau ua ib txoj hauj lwm zoo, yuav cov khoom siv nickel siab -raws li cov ntaub ntawv alloy, thiab xaiv cov nickel-raws li alloys raws li cov khoom ntawm cov hlau tsis sib xws thiab vuam yuav tsum tau ua, thiab nruj me ntsis thiab huv si huv welding hlau thiab workpiece ua ntej txheej txheem kom tsis txhob impurities cuam tshuam cov nyhuv vuam. Thaum lub sij hawm vuam, nws yog ib qho tsim nyog los tswj cov khoom siv hluav taws xob, kom tsis txhob muaj qhov kub ntawm lub sij hawm sib koom ua ke, txhim kho corrosion kuj ntawm qhov sib koom tes, thiab txo thiab tswj cov kab nrib pleb. Thaum vuam, nws yog ib qho tsim nyog yuav tsum xaiv qhov tsim nyog vuam ceev raws li qhov tseeb. Nws tsis tsim nyog ua kom nrawm dhau. Xaiv cov txheej txheem nqaim hlaws rau vuam, siv luv luv arc rau TIG vuam thiab arc vuam, thiab tswj cov txheej txheem kub hauv qab 100℃kom tsis txhob muaj vuam ntau dhau. Seam cuam tshuam cov nyhuv vuam.
Ua ntej tshaj plaws, thaum cov hlau tsis sib xws tau ua tiav los ntawm electrode arc vuam, cov khoom siv nickel-raws li alloy yuav tsum tau muab cov txheej txheem cais tawm. Nyob rau hauv tus txheej txheem ntawm kev txhim kho cov txheej txheem kev rho tawm, kev tshuaj xyuas tshwj xeeb yuav tsum tau nqa tawm ntawm txheej txheej cais. Thaum cov txheej txheem cais dhau los ntawm kev tshuaj xyuas, nws yuav tsum tau kho los ntawm kev kho cua sov. Lub hom phiaj ntawm kev kho mob yog txhawm rau tshem tawm cov kev ntxhov siab uas muaj nyob hauv cov txheej txheem cais tawm. Tom qab kev kho cua sov ua haujlwm, vuam pas nrig arc vuam thiab phau ntawv tungsten argon arc vuam yog siv los vuam austenitic stainless hlau thiab qis- alloy kub- cov hlau tsis muaj zog. Hauv kev ua haujlwm vuam tiag tiag, kev ua haujlwm yuav tsum tau ua raws li kev txiav txim tau piav qhia saum toj no. Thaum welding txheej cais, cov khoom siv vuam rau arc vuam thiab phau ntawv argon tungsten arc vuam yuav tsum tau siv, thiab qee qhov teeb meem yuav tsum tau them sai sai rau thaum thov cov khoom siv vuam raws li cov khoom siv.
Ua ntej tshaj, kev siv cov khoom siv vuam yuav tsum yog tus qauv uas tau teev tseg los ntawm lub xeev. Nyob rau hauv daim ntawv no, thaum welding txheej cais, npib tsib xee- cov khoom siv vuam feem ntau yog siv. Cov hlau muaj pes tsawg leeg ntawm npib tsib xee-raws li cov khoom siv vuam (vuam hlau thiab electrodes) yuav tsum ua tau raws li cov qauv sib xws. Nws yog ib qho tsim nyog los xaiv thiab tswj cov khoom siv vuam thaum cov txheej txheem sib cais yog welded. Vim tias yog tias cov khoom siv vuam tsis raug xaiv kom raug, qee qhov raug yuam kev yuav raug tshwm sim. Thaum lub sij hawm vuam txheej txheem ntawm kev sib cais txheej electrode, qhov loj thiab polarity ntawm tam sim no yuav tsum tau raws li qhov yuav tsum tau ua. Xaiv cov nickel-raws li cov ntaub ntawv vuam rau vuam yuav tsis tsuas yog ua kom cov txheej txheem sib cais ua tau raws li tus qauv, tab sis kuj tseem txhim kho tag nrho cov welded sib koom ua ke, uas yuav ua rau muaj kev pab zoo dua rau kev sib tsoo ntawm cov hlau sib txawv. Nyob rau tib lub sijhawm, nws tseem yuav ua kom muaj kev nyab xeeb ntawm kev sib koom ua ke thiab kev tsim kho, thiab ua kom lub neej kev pab cuam thiab siv cov nyhuv ntawm cov welded sib koom ua ke.
Tom qab lub vuam tiav lawm, 100% radiographic tshuaj xyuas ntawm lub welded sib koom ua ke yog ua raws li cov kev soj ntsuam xyuas ntawm cov welded sib koom ua ke ntawm cov qauv, thiab tej yam thwmsim, dabtsi yog khoov thwmsim thiab tensile thwmsim yog nqa tawm nyob rau hauv lub welded sib koom ua ke raws li cov kev soj ntsuam cov hlab ntsha. Cov txiaj ntsig kev sim qhia tau hais tias lub zog tensile ntawm qhov sib koom ua ke tuaj yeem txhim kho tau zoo los ntawm kev siv npib tsib xee-raws li alloy raws li cov txheej txheem vuam ntawm cov txheej txheem sib cais, ua rau nws siab dua li cov nqi teev tseg. Tom qab khoov cov qauv, tsis muaj qhov tsis xws luag thiab cov kab nrib pleb, uas qhia tau hais tias cov qauv muaj cov yas zoo thiab qhov sib koom ua ke yog ntom thiab txuas ntxiv. Nws tuaj yeem pom los ntawm qhov kev ntsuam xyuas tias qhov tsim nyog daim ntawv thov ntawm nickel-raws li alloy nyob rau hauv cov txheej txheem vuam ntawm cov hlau tsis sib xws tuaj yeem txhim kho qhov vuam zoo, xyuas kom muaj kev siv cov pob qij txha, thiab ua kom lub neej ntev ntawm cov khoom siv.
Piv txwv li, npib tsib xee-raws li alloys muaj txiaj ntsig zoo hauv cov txheej txheem vuam ntawm cov hlau tsis sib xws. Los ntawm cov npib tsib xee-raws li cov txheej txheem kev sib cais ntawm cov pa roj carbon monoxide, cov pa roj carbon monoxide tuaj yeem ua rau muaj kev cuam tshuam zoo, cov hlau welded yog diluted thiab cov kev ntxhov siab seem yuav raug txo kom tsawg, thiaj li ua kom cov vuam ntawm cov welded pob qij txha thiab txhim kho kev siv tau zoo thaum vuam. Nws muaj txiaj ntsig zoo rau kev siv vuam ntawm cov hlau tsis sib xws.
