Porosity, kab noj hniav-hom discontinuities tsim los ntawm gas entrapment thaum lub sij hawm solidification, yog ib tug ntau tab sis cumbersome defect nyob rau hauv MIG vuam thiab ib tug muaj ob peb ua. Nws tuaj yeem tshwm sim hauv daim ntawv sau npe semi-automatic lossis robotic thiab yuav tsum tau tshem tawm thiab rov ua haujlwm hauv ob qho tib si - ua rau poob qis thiab nce nqi.
Qhov laj thawj tseem ceeb ntawm porosity hauv steel vuam yog nitrogen (N2), uas tau koom nrog hauv lub pas dej welding. Thaum lub pas dej ua kua txias, qhov solubility ntawm N2 txo qis thiab N2 los ntawm cov hlau molten, tsim npuas (qhov pores). Nyob rau hauv galvanized / galvanneal vuam, evaporated zinc tuaj yeem raug nplawm rau hauv lub pas dej ua ke, thiab yog tias tsis muaj sijhawm txaus los khiav ua ntej lub pas dej ua ke, nws tsim porosity. Rau txhuas vuam, tag nrho cov porosity yog tshwm sim los ntawm hydrogen (H2), los ntawm tib txoj kev raws li N2 ua hauj lwm nyob rau hauv steel.
Vuam porosity tuaj yeem tshwm sab nraud lossis sab hauv (feem ntau hu ua sub-surface porosity). Nws kuj tuaj yeem txhim kho ntawm ib qho taw tes ntawm qhov vuam lossis raws tag nrho qhov ntev, ua rau cov welds tsis muaj zog.
Paub yuav ua li cas txheeb xyuas qee qhov laj thawj tseem ceeb ntawm porosity thiab yuav daws sai npaum li cas tuaj yeem pab txhim kho qhov zoo, tsim khoom thiab cov kab hauv qab.
Tsis zoo Shielding Gas Coverage
Kev tiv thaiv roj tsis zoo yog qhov feem ntau ua rau vuam porosity, raws li nws tso cai rau cov pa roj cua (N2 thiab H2) kom paug cov pas dej. Tsis muaj kev pov hwm tsim nyog tuaj yeem tshwm sim rau ntau qhov laj thawj, suav nrog tab sis tsis txwv rau kev tiv thaiv tsis zoo ntawm cov roj ntws tawm, xau hauv cov roj channel, lossis huab cua ntau dhau hauv cov xov tooj ntawm tes. Kev mus txawv tebchaws uas ceev dhau kuj tuaj yeem ua txhaum cai.
Yog tias tus neeg teb xov tooj xav tias qhov dej ntws tsis zoo yuav ua rau muaj teeb meem, sim kho cov pa ntsuas ntsuas kom paub tseeb tias tus nqi txaus. Thaum siv cov tshuaj tsuag hloov pauv, piv txwv li, 35 mus rau 50 cubic feet ib teev (cfh) yuav tsum txaus. Vuam ntawm ntau dua amperages yuav tsum tau nce tus nqi ntws, tab sis nws tseem ceeb heev kom tsis txhob teeb tsa tus nqi siab dhau. Qhov no tuaj yeem ua rau muaj kev kub ntxhov hauv qee qhov kev tsim phom uas cuam tshuam kev tiv thaiv kev tiv thaiv roj.
Nws yog ib qho tseem ceeb kom nco ntsoov tias cov phom sib txawv muaj cov yam ntxwv sib txawv ntawm cov pa roj (saib ob qho piv txwv hauv qab no). Qhov "qab zib qhov chaw" ntawm cov roj ntws tus nqi rau sab saum toj tsim yog ntau loj dua li ntawm cov qauv hauv qab. Qhov no yog ib yam dab tsi uas tus kws ua haujlwm vuam yuav tsum tau xav txog thaum teeb tsa lub vuam cell.
Tsim 1 qhia tau hais tias cov roj ntws zoo ntawm lub qhov hluav taws xob nozzle
Tsim 2 qhia tau hais tias turbulent gas flow ntawm lub nozzle qhov hluav taws xob.
Kuj xyuas qhov kev puas tsuaj rau cov roj hose, fittings thiab connectors, nrog rau O-rings ntawm lub hwj chim tus pin ntawm MIG vuam phom. Hloov raws li qhov tsim nyog.
Thaum siv cov kiv cua kom txias cov tswv lag luam lossis cov khoom hauv lub xov tooj ntawm tes, saib xyuas kom lawv tsis tau taw qhia ncaj qha rau ntawm qhov chaw vuam uas lawv tuaj yeem cuam tshuam cov pa roj. Muab ib qho screen rau hauv lub xov tooj ntawm tes los tiv thaiv los ntawm cov huab cua sab nraud.
Rov kov qhov kev zov me nyuam hauv cov ntawv thov neeg hlau kom paub tseeb tias muaj qhov ua haujlwm kom zoo, uas feem ntau yog ½ txog 3/4 nti, nyob ntawm qhov xav tau ntev ntawm lub arc.
Thaum kawg, kev mus los qeeb qeeb yog tias qhov porosity txuas ntxiv los yog sab laj nrog MIG tus neeg muag khoom rau cov khoom sib txawv pem hauv ntej kawg nrog cov roj npog zoo dua.
Base Hlau Contamination
Base hlau paug yog lwm qhov laj thawj porosity tshwm sim - los ntawm cov roj thiab roj rau zeb nplai thiab xeb. Cov dej noo kuj tuaj yeem txhawb qhov tsis sib xws, tshwj xeeb tshaj yog nyob rau hauv aluminium vuam. Cov hom kab mob no feem ntau ua rau sab nraud porosity uas pom rau tus neeg teb xov tooj. Galvanized steel yog ntau yooj yim rau subsurface porosity.
Txhawm rau tiv thaiv cov porosity sab nraud, nco ntsoov ntxuav lub hauv paus kom huv si ua ntej vuam thiab txiav txim siab siv cov hlau-cored vuam hlau. Hom hlau no muaj cov deoxidizers ntau dua li cov xaim hlau, yog li nws muaj kev tiv thaiv ntau dua ntawm cov khoom seem ntawm cov khoom siv hauv paus. Nco ntsoov khaws cov no thiab lwm cov xov hlau nyob rau hauv qhov chaw qhuav, huv si ntawm qhov zoo sib xws lossis me ntsis siab dua cov nroj tsuag. Ua li no yuav pab txo qis condensation uas tuaj yeem qhia cov dej noo rau hauv lub pas dej ua ke thiab ua rau porosity. Tsis txhob khaws cov xov hlau hauv lub tsev txias lossis sab nraum zoov.
Porosity, kab noj hniav-hom discontinuities tsim los ntawm gas entrapment thaum lub sij hawm solidification, yog ib tug ntau tab sis cumbersome defect nyob rau hauv MIG vuam thiab ib tug muaj ob peb ua.
Thaum vuam galvanized steel, zinc vaporizes ntawm qhov kub qis dua cov hlau melts, thiab ceev ceev mus los yuav ua rau lub pas dej weld khov sai. Qhov no tuaj yeem ntes zinc vapor hauv cov hlau, ua rau muaj qhov porosity. Tiv thaiv qhov xwm txheej no los ntawm kev saib xyuas kev mus ncig ceev. Ntxiv dua thiab, xav txog tshwj xeeb tsim (flux formula) hlau-cored hlau uas txhawb zinc vapor khiav tawm ntawm lub pas dej welding.
Clogged thiab/los yog Undersized Nozzles
Clogging thiab / los yog undersized nozzles kuj tuaj yeem ua rau porosity. Vuam spatter tuaj yeem tsim nyob rau hauv lub nozzle thiab nyob rau saum npoo ntawm qhov kev sib cuag thiab diffuser ua rau muaj kev txwv tsis pub muaj roj ntws los yog ua rau nws ua rau muaj kev kub ntxhov. Ob qhov xwm txheej tawm hauv lub pas dej ua ke nrog kev tiv thaiv tsis txaus.
Compounding qhov teeb meem no yog ib tug nozzle uas yog me me heev rau daim ntawv thov thiab ntau nws yuav ntau dua thiab sai spatter buildup. Cov nozzles me me tuaj yeem muab kev sib koom ua ke zoo dua, tab sis kuj cuam tshuam cov roj ntws vim qhov chaw me me uas tau tso cai rau cov roj ntws. Nco ntsoov nco ntsoov qhov sib txawv ntawm qhov kev sib cuag ntawm lub taub hau rau lub taub hau (lossis so), vim qhov no tuaj yeem yog lwm yam uas cuam tshuam rau kev tiv thaiv cov roj ntws thiab qhov porosity nrog koj qhov kev xaiv nozzle.
Nrog rau qhov ntawd hauv siab, xyuas kom lub nozzle loj txaus rau daim ntawv thov. Feem ntau, cov ntawv thov uas muaj vuam tam sim no siv cov hlau loj dua yuav tsum muaj lub taub hau nrog qhov loj dua.
Nyob rau hauv ib daim ntawv thov vuam semi-automatic, ib ntus tshawb xyuas cov vuam tawg hauv lub nozzle thiab tshem tawm siv cov vuam pliers (welpers) lossis hloov lub nozzle yog tias tsim nyog. Thaum lub sij hawm soj ntsuam no, paub meej tias cov lus qhia kev sib cuag tau zoo thiab cov roj diffuser muaj cov chaw nres nkoj ntshiab. Cov neeg ua haujlwm kuj tseem tuaj yeem siv cov tshuaj tiv thaiv kab mob sib kis, tab sis lawv yuav tsum tau saib xyuas kom tsis txhob poob lub nozzle rau hauv qhov sib xyaw kom deb lossis ntev dhau, vim tias cov khoom siv ntau dhau tuaj yeem ua rau cov pa tiv thaiv kab mob thiab ua rau lub nozzle rwb thaiv tsev puas.
Hauv kev ua haujlwm vuam robotic, nqis peev rau hauv qhov chaw tu lub nozzle lossis reamer los tiv thaiv kev sib tsoo. Qhov no peripheral cleans lub nozzle thiab diffuser thaum lub sij hawm ib txwm nres nyob rau hauv ntau lawm thiaj li hais tias nws tsis cuam tshuam rau lub sij hawm voj voog. Nozzle ntxuav chaw yog npaj los ua hauj lwm ua ke nrog ib tug anti-spatter sprayer, uas siv ib tug nyias lub tsho tiv no ntawm compound rau pem hauv ntej Cheebtsam. Cov kua dej ntau dhau los yog tsawg dhau los tuaj yeem ua rau muaj qhov porosity ntxiv. Ntxiv nyob rau hauv huab cua moj tej tawg mus rau lub nozzle tu txheej txheem kuj pab nyob rau hauv clearing xoob spatter los ntawm consumables.
Ua kom zoo thiab tsim khoom
Los ntawm kev saib xyuas los saib xyuas cov txheej txheem vuam thiab paub qhov ua rau ntawm qhov porosity, nws yooj yim heev los siv cov kev daws teeb meem. Ua li no tuaj yeem pab ua kom muaj lub sijhawm zoo dua qub, cov txiaj ntsig zoo thiab ntau qhov chaw zoo txav mus los ntawm kev tsim khoom.
Post lub sij hawm: Feb-02-2020
