船用耐蚀钢DH36光纤激光-MIG复合焊接头组织和性能  

Microstructures and properties of fiber laser-MIG hybrid welded joints for marine corrosion resistant steel DH36

作　　者：高艳[1] 崔丽[1] 常耀卿 顾长石[2] 贺定勇[1] GAO Yan;CUI Li;CHANG Yaoqing;GU Changshi;HE Dingyong(Beijing University of Technology,Beijing 100124,China;Shipbuilding Technology Research Institute,Shanghai 200032,China)

机构地区：[1]北京工业大学,北京100124 [2]上海船舶工艺研究所,上海200032

出　　处：《焊接学报》2019年第5期60-66,I0004,I0005,共9页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51475006)

摘　　要：为探索12 mm厚DH36船用耐蚀钢对接用光纤激光-MIG复合焊接工艺,分析了四种不同送丝速度对接头成形、微观组织、拉伸性能及腐蚀性能的影响.结果表明,在送丝速度为8.5 m/min时可获得成形优良的接头,随着送丝速度的增加,电弧区和激光区焊缝的熔宽均增加.焊缝区主要由针状铁素体、先共析铁素体和一定量的贝氏体组成,送丝速度对针状铁素体的形态和数量有显著的影响.增加送丝速度对接头抗拉强度的影响不大,但减小了断后伸长率,接头断后伸长率最高达16.5%.接头极化曲线测试表明,当送丝速度为7.5 m/min时,自腐蚀电流密度最小,腐蚀倾向最低.The marine corrosion resistant steel DH36 plates of 12 mm thickness were welded by using fiber laser-MIG hybrid welding process.The effects of wire feeding speeds on the cross section shapes,microstructures,mechanical properties and corrosion resistance of the joints were studied.The results show that with the wire feeding speed increasing from 7.0 m/min to 8.5 m/min,the weld width of arc zone rises from 8.44 mm to 10.03 mm while the weld width of laser zone increases from 1.63 mm to 2.09 mm.The wire feeding speeds have no obvious influence on the phase types of weld microstructures,which consists predominantly of acicular ferrite(AF),pro-eutectoid ferrite(GBF)and a small amount of bainite(B).As the wire feeding speed increases,the morphology and amount of AF were changed.The microstructure of the HAZ of the joint was composed of ferrite(F),pearlite(P)and a small amount of bainite(B).In addition,the increase of wire feeding speeds has little effect on the joint strength,but has an significant effect on the elongation of the joints.Increasing the wire feeding speed reduces the elongation of the joints,and when the wire feeding speed is 7.0 m/min,the elongation is up to 16.5%.The polarization curves of the joints showed that the corrosion tendency was the lowest when the wire feed speed was 7.5 m/min and the corrosion tendency was the highest when the wire feed speed was 7.0 m/min.

关 键 词：送丝速度 激光-MIG复合焊 耐蚀钢 组织 性能 

分 类 号：TG456.7[金属学及工艺—焊接]