资源描述：
《电焊参考题（welding reference）》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、电焊参考题（Weldingreference）TheprimarytheoreticalexaminationofweldersFillinaproblem;1.buttweldingwithdifferentthicknesssteelplateforgirthweldingshouldbecarriedout.2.thebasicformofweldedjointcanbedividedinto(buttjoint),(anglejoint),(typeTjoint),(lapjoint).3.weldingcommondefectsintheweldare(blowho
2、le),(slag),(crack),(insoluble),(notwelded),(tungsten)andsoon.4.thelengthofweldingcableisnotmorethan(20)meters.5.theweldingelectrodewithlargerthicknessshouldchoosetheelectrodewithbiggerdiameter.6.thechoiceofelectrodediametershouldbeconsidered(thicknessofweldment),(typeofjoint),(positionofwel
3、ding),(numberofweldinglayers).7.generalarcweldingprocessincludes(ignitionarc),(normalwelding),(quenchingending).8.themaindangersofweldingoperationsinlimitedspaceplacesarehypoxia,suffocation,(toxicandharmfulgas),(explosiveandflammable),andeasytoshock.9.intheflammable,explosive,toxic,suffocat
4、ionandotherenvironmentsbeforeweldingoperations,mustbe(replacement)and(cleaning)operations.10.weldingrodisdamp,theweldingprocessperformancebecomesworse,andthehydrogeninwateriseasytoproduce(blowhole),crackandsoon.11.thefivemajorelementsincommonsteel,themainelementsaffectingtheweldingperforman
5、cearecarbon,sulfurandphosphorus.12.gasshieldedweldingcanbedividedinto(MIGwelding),(nonMIGwelding)twocategories.ThirteenThefollowingoperationshouldbedoneafter(cuttingoffthepowersupply),changingtheweldingjoint,changingthetworeturnline,transferringtheworkingplace,overhaulingtheweldingmachinean
6、dreplacingthefuse.Themainweldingparametersofautomaticsubmergedarcwelding(14.)areweldingcurrent,arcvoltageandweldingspeed.15.weldingresidualdeformationcorrectionmethod(mechanicalcorrectionmethod)and(flameheatingcorrectionmethod)twocategories.Thefatiguestrengthofbuttjointisthehighestamongthe1
7、6.weldedjoints.17.(preheating)canreducethecoolingrateofweldmentafterwelding.18.themethodstoeliminateorreducetheweldingresidualstressare(wholehightemperaturetempering),(localhightemperaturetempering),(mechanicalstretchingmethod),(temperaturestretchingmeth
