Nrum alloys, siv dav hauv kev lag luam, tshuab hluav taws xob, feem ntau xav tau cov khoom sib xyaw ua ke los ua cov khoom sib xyaw (piv txwv li (piv txwv li, kho cov kab nrib pleb lossis hnav). Ib lo lus nug uas nquag muaj nyob hauv cov voj voog muaj: Koj puas tuaj yeem thaiv cov xoob? Cov lus teb yog - tab sis nrog tseem ceeb caveats. Vuam nrum alloys yog ua tau tab sis xav tau kev paub tshwj xeeb ntawm lawv cov microstructure, raws li lawv cov khoom txawv los ntawm wrought alloys. Cov ntawv no tshawb txog qhov weldability ntawm cam khwb cia alloys, cov nyom tseem ceeb, thiab kev sib tw vuam cov kev daws teeb meem.
Nrum alloys raug tsim los ntawm poling hlau mus ua pwm, ua kom zoo nkauj {}- uas cuam tshuam weldability. Lawv cov tshuaj lom neeg muaj tshuaj, feem ntau tsim rau Castability (piv txwv li ntau dua carbon hauv cam khwb cia hlau, silicon hauv nrum txhuas), qhia cov kev sib tw vuam:
Nrib pleb kev phom sij: Muaj cov pa roj carbon ntau: Cov pa roj carbon ntau hauv cov hlau cam khwb cia tuaj yeem tsim cov carbides lossis cov leej faj hauv thaj chaw weld. Nrumines cov ntsiab lus silicon siab yuav ua rau kub tawg thaum lub solorification.
Porosity: Gases cuab thaum lub sij hawm casting (piv txwv li, hydrogen nyob rau hauv cam le caag) tuaj yeem tsiv mus rau hauv weld pas dej, ua pores.
Kev Tsim Khoom Siv Microstration: cua sov thaum lub sij hawm vuam vuam tuaj yeem hloov cov cam alloy's matrix, piv txwv li, emnithling hauv cam kas cast).
Weldability sib txawv los ntawm cam khwb cia alloy hom, nrog cov hauv kev sib txawv uas xav tau rau ferrous thiab tsis {{ferrous cams.
Vuam Ferrous Nrum Alloys
Ferrous nrum alloys (piv txwv li, cam khwb cia hlau, hlau cam khwb cia) tau siv dav hauv lub cav thaiv, gearboxes, thiab cov qauv txheej txheem. Lawv weldability yog nyob ntawm cov ntsiab lus carbon thiab alloy cov ntsiab.
Nrum Hlau
Cam khwb cia hlau, nrog 2% -4% carbon thiab 1% -3% silicon, yog cov lus qhia nyuaj rau weld vim nws cov ntsiab lus carbon siab. Txawm li cas los xij, tswj cov txheej txheem ua kom muaj kev vam meej vuam vuam:
Grey cam khwb cia hlau: muaj flake graphite, nquag mus tawg vim yog qhov ua tiav qis. Kev Vuam Txoj Kev Sib Tw Muaj xws li:
Brazing: Siv lub tooj liab - refle fatter hlau (melting taw tes<840°C) to avoid melting the base metal, reducing cracking risk. Suitable for non-load-bearing repairs.
Arc vuam nrog nickel -}} Kev tsiv teb tsaws chaw rau WELD, tiv thaiv kev tsim lub welittite. Preheating (200-350 degree) thiab tshaj tawm - weld annealing (qeeb cua txias hauv qhov cub) txo kev ntxhov siab.
Zas nrum hlau: spheroidal graphite txhim kho kev nruj, tab sis tseem xav tau kev saib xyuas. Roj Hlau Hlau Arc Vuam (Gmaw) nrog qis- chromium muab cov hlau (piv txwv li (150-250 degree) yog ua tau zoo rau kev hloov cov txheej txheem.
Nrum Hlau
Cam khwb cia hlau (carbon<2%, alloyed with chromium, nickel, or molybdenum) has better weldability than cast iron, resembling wrought steel but with coarser grains:
Cov Kev Vuam Cov Hlau: Cov thaiv hlau arc vuam (smaw) lossis roj tungsten sib txuas ntawm cov pob zeb sib xyaw (piv txwv li}}}
Cov Tseem Ceeb Tswj: Preheat rau 150-300 Qib (nyob ntawm cov ntsiab lus carbon) kom txias txias, zam kev sib ntaus sib tua. Post - Weld Kev Kho Cua Sov (PWHT) ntawm 600-650℃thim kev ntxhov siab.
Welding tsis - ferrous cam alloys
Tsis {{0} rerrous nrum alloys, xws li nrum txhuas, nrum tooj liab, yog qhov tseem ceeb hauv kev siv tawv. Lawv weldability yog los ntawm oxide tsim thiab thermal conductivity.
Nrum Txhuas Alloys
Nrum Aluminium (piv txwv li, 356, A380) muaj silicon (5% -13%) rau Castability tab sis yog nquag tawg tawg thiab oxide) cuam tshuam: kev cuam tshuam) kev cuam tshuam:
Kev npaj saum npoo: automate Tshem tawm (kev txhuam hlau) lossis tshuaj txhuam etching yog yuav tsum tau ua, raws li al₂o₃ muaj lub ntsiab lus melting (2072 degree) ntau dua li txhuas (660 degree).
Cov Kev Vuam Cov Qauv: GTAW nrog Silicon {{0 g, 4043, 5356) kom phim cov cam khwb cia Alloy txoj kev sib xyaw, txo qis. Preheating (120-200 degree) rau cov kab tuab txhim kho fusion.
Tshaj tawm - Kev Kho Mob Weld: Kev daws teeb meem kub (Kev daws teeb meem) Yuav tsum muaj rau cua sov {
Nruj Copper alloys
Nrum tooj liab alloys (piv txwv li, tooj dag) muaj siab thermal conductivity, ua rau cua sov kom dissipate sai ntawm lub pas dej weld:
Vuam txoj kev: oxy - acetylene vuam (rau cov chaw ua haujlwm me me) lossis get, silicon bronze muab tub luam).
Cov Tseem Ceeb Tswj: Siv cov tswv yim kub siab thiab nqaim Weld hlaws dai kom tswj fusion. Rau cov ua cam khwb cia tooj dag (cov ntsiab lus zoo), tsis txhob vuam vim yog cov tshuaj lom txhuas - brazing yog qhov nyiam.
Kev Tshawb Xyuas Kev Ua Pom Zoo Tshaj Plaws Rau Nrum Alloys
Ntse vuam nrum alloys yuav tsum muaj txoj hauv kev ua haujlwm:
Alloy Qhia Txog: Siv tshuaj lom neeg lossis tshuaj ntsuam xyuas kom paub meej tias cov cam khwb cia alloy (piv txwv li, paub qhov txawv xim hlau los ntawm cov hlau nrum hlau) ua ntej xaiv cov txheej txheem.
Pre6 - Weld soj ntsuam: Siv kev kuaj ultrasonic (U) los tshawb xyuas zais porosity lossis cov kab nrib pleb hauv cov hlau cam khwb cia hlau, uas tuaj yeem nthuav tawm thaum lub sij hawm vuam.
Kev Xaiv Hlau Sau Cov Ntawv Sau: Match muab tso rau alloy rau cov cam khwb cia aliroys rau cam nyuj xim rau cam coatic) kom tsis txhob muaj intermetallics.
Kev tswj hwm cua sov: Preheat kom txo cov nqi txias txias, tswj cov ncej kub, thiab siv cov ntsiab lus werrous) lossis kev ntxhov siab} ferrous) los txo kev tawg.
Tshaj tawm - Weld kuaj: Siv zas xim kev sim (RT) lossis ntsuas kev ncaj ncees Weld (Tensile, Hardness) rau cov ntawv tseem ceeb.
Kev muaj qhov tseem ceeb ntawm cam khwb cia alloy vuam
Vuam nrum alloys Enabes siv tus nqi -}}}} {1}- tus nqi Cheebtsam. Hauv kho cov kev kho kho hauv cov pob, vuam kho kom rov qab tawg cam khwb cia hlau cav thaiv, tsis txhob hloov tag nrho. Hauv Aerospace, koom nrog cam titanium alloy cov cheebtsam kom tau siv qhov hnyav txo qhov hnyav thiab kev sib dhos. Rau cov tshuab hnyav, vuam kho cov cuab yeej pob zeb hydraulic, txo qis downtime.
Advances in welding technology-such as pulsed GTAW for cast aluminum (reducing spatter and porosity) and low-heat laser welding for cast iron (minimizing distortion)-continue to expand the feasibility of cast alloy welding.
Hauv kev xaus, pov tseg cov alloys tuaj yeem welded, tab sis nws yog ib qho txheej txheem tshwj xeeb uas xav tau kev paub txog ntawm Alloy cov yam ntxwv thiab lub hom phiaj vuam. Tus yuam sij tsis yog tias yuav ua tau kev sib tw ua tau, tab sis yuav ua li cas daws cov kev sib tw xws li kev xaiv, kev xaiv cov txheej txheem, thiab kev tswj hwm thaum cua sov. Nrog kev ua haujlwm ua tiav, Vuam nrum alloys tseem muaj qhov sib txawv hauv kev tsim kho niaj hnub ntawm kev tsim cov khoom siv thiab cov kev xav tau ntawm cov ntawv thov kev lag luam.
