Agroupofprojectionweldingexperimentsandjointstension-sheartestsarecarriedoutforcold-rolledsteelsheets,galvanizedsteelsheets(GSS)withouttreatment,GSSwithphosphatingandGSSwithsurfacegreasing,respectively.Theexperimentalresultsareregressivelyanalyzedonthecomputers,thentheprojectionweldedjointtension-shearstrengthcurveandtheperfectweldingcurrentsrangeofeachmaterialareobtained.Theresultsshowthatsurfacetreatmentsofgalvanizedsteelshaveeffectsontheirspotweldabilities.Amongthefourkindsofmaterials,GSSwithsurfacegreasinghavetheworstspotweldability,fortheyneedhigherweldingcurrentandhaveanarrowweldingcurrentrange.
