Abstract
Withtherapideconomicandsocialdevelopment,constructionmachinerytendsto
bemorelarge-scale,morelightweight,andsafer.Traditionallow-alloysteelhasbeen
graduallyreplacedbyhigh-strengthsteel,anditsapplicationinthefieldofconstruction
machinerymanufacturingbecomesmoreandmoreextensive.Thesuccessfuldesignand
applicationofconstructionmachineryproductsnotonlydependonthedesignand
selectionofsteelmaterials,butalsogreatlydependonthedesignoftheweldingprocess
andtheweldingqualityoftheproduct.
Basedontheanalysisofstrengtheningandtougheningmechanismofquenched
andtemperedhighstrengthsteel,thedesigncompositionandkeypreparationprocess
parametersofQ890Dsteelplateweredetermined.Thetestresultsofsteelplate
propertiesandmetallographicstructureshowsthatthesteelplatepreparedbycleansteel
smeltingtechnology,controlledrollingandcontrolledcoolingtechnologycombined
withoff-linequenchedandtemperedheattreatmentprocesshasverygood
comprehensivemechanicalpropertiesaswellasuniformandfinemicrostructurealong
thethicknessdirection,Thesteelcanmeetwiththedesignrequirementsofhighstrength
steelinthefieldofconstructionmachinery.Combinedwiththedemandofconstruction
machinerysteel,theweldingperformanceofQ890Dhighstrengthsteelisalso
evaluatedbybothweldingcold-cracksensitivitytestandcomprehensivemechanical
propertytest,andthekeyweldingprocessparametersofsteelplatearedetermined.
Whentheweldingpreheatingtemperatureisbetween150~200℃,theoccurrenceof
weldingcold-crackcanbeeffecti