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1、电焊技术入门基础（Fundamentalsofweldingtechnology）BasicknowledgeofweldingskillapplicationWeldingiswidelyused,allwalksoflifeneedit,averypopularskills.Weldingisaneasytolearntechnology,buttousewell,itdependsontheindividual'sunderstandingability,plusthetheoryandpractic
2、eoflearning.Istheactualclassificationofweldingwelding,cuttingandsimilar.Ordinaryweldingwithargonarcwelding,gasweldingandsoon.Whatkindsofweldingmethodsarethereforelectricwelding(manualwelding)?1G:2G:flatorrotatingtransverseorverticalfixedwelding3G:4G:5G:6G:
3、45leveloffixedoverheadwelding:weldingfixeddegree5GX(down)t:fillet(variouslocations)Whenweldingseam,howtoweldthemostplane?Weldingwitharcweldingformingisbetterthancurrent,current10%smallflat,theangleis70to75degrees.Weusuallyuseserratedandcrescenttransportmet
4、hod,ismainlyapplicableforyourself.Whenweldingseam,sometimesthereisasmallcrackwhatisthematter?Therearemanyreasonsforthecracks,whichcanbefoundfromthefollowingaspects:Whatkindofmaterialis1.,whichshouldbechosen,accordingtothematerialandweldingmaterial;2.joints
5、,choosesuitableweldingcriterion,whennecessarythroughthetesttodeterminetheweldingprocessparameters,butalsopayattentiontothecontrollayertemperaturewhenmultipasswelding;3.accordingtotheexperience,suchthicktwopiecesofwelding,shouldbepreheatedbeforewelding.Ther
6、easonandsolutionofthecracksafterweldingarediscussedThecauseofcracks:1.weldshrinkagestressistoolarge,easytoproduceslowcracks.2.weldunevenheating,pronetobrittleness.3.weldingmethodandsequenceunreasonable.Temperaturecontrolbetween4.floorsisnotgood.Preventionm
7、easures:1.,thereasonableweldingsequenceshouldbeselectedandsymmetricalweldingshouldbeadopted.2.,multilayer,multipasswelding,weldingeachweld(notbackingwelding),shouldseriouslydealwiththeweldingsurfaceweldingslag,oxideskin,inordertopreventthestolengoodsinthen
8、extlayerofwelddefects.3.adjustthecoolingrate,thefasterthecooling,thegreaterthedeformation.Thetendencyofcrystallinecracksisalsogreater.Eliminationofresidualstressafter4.welding.Howcanelectricweldingbeweldedfla
