无镀铜焊丝焊接S355J2W+N耐候钢的焊接接头性能与组织

Properties and Microstructure of S355J2W+N Weathering Steel Welded with Non-coppered Wire

采用无镀铜焊丝对12 mm厚S355J2W+N耐候钢进行MAG焊接试验,通过拉伸试验、弯曲试验、冲击试验、硬度试验、金相组织和断口组织分析的方法,进行S355J2W+N无镀铜焊丝接头性能的研究。结果表明,无镀铜焊丝焊接的S355J2W+N耐候钢焊接接头具有良好的拉伸和弯曲性能,抗拉强度和屈服强度均高于母材标准值,断口呈韧性断裂特征。焊缝冲击韧性低于焊接热影响区,且随温度的降低而下降,但均满足母材冲击功不低于27 J(-20℃)的标准要求。焊接接头各区域的硬度符合ISO15614-1标准,均小于HV380,母材区域硬度最低,过热区硬度最高,焊接热影响区的硬度波动最大。金相组织分析表明,焊接接头由焊缝区、过热区、相变重结晶区和不完全相变重结晶区组成,相变重结晶区组织细小均匀,性能最佳。无镀铜焊丝焊接的S355J2W+N耐候钢焊接接头的性能满足生产标准要求。

The study on the performance of S355J2W+N weathering steel welded joints using non-copper coated welding wire OK AristoRod 13.26 involved MAG welding tests on 12 mm thick steel.The research methods included tensile testing,bending testing,impact testing,hardness testing,metallographic structure analysis,and fracture surface analysis.The results indicate that the welded joints of S355J2W+N weathering steel using non-copper coated welding wire exhibit good tensile and bending properties,with tensile strength and yield strength higher than the standard values of the base material,and the fracture surface shows characteristics of ductile fracture.The impact toughness of the weld is lower than that of the heat-affected zone and decreases with decreasing temperature,but both meet the standard requirement that the impact energy of the base material should not be less than 27 J(-20℃).The hardness of various regions of the welded joint conforms to the ISO15614-1 standard,all being less than HV380,with the base material having the lowest hardness,the over-heated zone the highest,and the greatest fluctuation in hardness observed in the heat-affected zone.Metallographic structure analysis shows that the welded joint consists of weld zone,over-heated zone,phase transformation recrystallization zone,and incomplete phase transformation recrystallization zone,with the phase transformation recrystallization zone having fine and uniform structures,exhibiting the best performance.The performance of S355J2W+N weathering steel welded joints using non-copper coated welding wire meets the production standard requirements.