G115钢CMT+P焊接工艺及组织和性能  

Microstructure and mechanical properties of CMT + Pwelding process on G115 steel

作　　者：徐连勇[1,2,3] 庞红宁 赵雷 韩永典[1,2] 迟大钊[3] XU Lianyong;PANGHongning;ZHAO Lei;HAN Yongdian;CHI Dazhao(Tianjin University,Tianjin,300072,China;Tianjin Key Laboratory of Advanced Joining Technology,Tianjin,300072,China;State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Habin,150001,China)

机构地区：[1]天津大学,天津300072 [2]天津市现代连接技术重点实验室,天津300072 [3]哈尔滨工业大学,先进焊接与连接国家重点实验室,哈尔滨150001

出　　处：《焊接学报》2020年第8期1-5,I0001,共6页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51975405);哈尔滨工业大学现代焊接国家重点实验室基金资助项目(AWJ-20-R01).

摘　　要：基于冷金属过渡加脉冲(CMT+P)的焊接方法,研究了新型回火马氏体耐热钢G115的焊接性以及焊接接头组织和性能.结果表明,焊接接头经热处理后为回火马氏体组织,焊缝晶粒呈现出等轴晶和柱状晶两种不同的形貌,而焊接热影响区和母材晶粒均为等轴晶.与焊条电弧焊(SMAW)相比,CMT+P焊接方法有效降低了热输入,大幅度减小了热影响区宽度,提高了焊接接头的拉伸性能和热影响区冲击韧性,焊接接头焊缝冲击韧性略有降低.焊接接头的室温和高温拉伸断裂机理均为韧性断裂,室温拉伸断口的韧窝内存在一定量的析出相.Based on cold metal transfer+pulse welding(CMT+P)welding method,the weldability of G115,a novel tempered martensitic heat resisting steel,microstructures and mechanical properties of welding joint were studied.The results showed that the microstructure of the welding joint was tempered martensite after welding and heat treatment.Two different grains were found in the weld metal,while both the weld heat affected zone and the base metal were equiaxed grains.Compared with manual arc welding(SMAW),CMT+P welding method reduces the heat input effectively,diminishing the size of the heat-affected area prominently,improving the tensile performance of the welded joint and the impact toughness of the heat-affected area,weakening the impact toughness of the welded joint slightly.The tensile fracture mechanism of welded joints at room and high temperature is ductile fracture.A certain amount of precipitate exists in the dimples of tensile fracture at room temperature.

关 键 词：新型回火马氏体耐热钢 微观组织 力学性能 冷金属过渡 

分 类 号：TG444[金属学及工艺—焊接]