5CrNiMo热作模具CO_2气体保护焊修复用药芯焊丝研制  

Development of flux-cored wire for repairing 5CrNiMo hot-working die with CO_2-gas shielding arc welding

作　　者：李昱[1] 余圣甫[1] 

机构地区：[1]华中科技大学材料科学与工程学院,武汉430074

出　　处：《焊接》2017年第6期39-43,共5页Welding & Joining

摘　　要：开发了用于5CrNiMo热作模具修复的药芯焊丝,用高速摄影观察NaF含量对焊接电弧稳定性的影响,并对堆焊层金属组织和力学性能进行测试分析。结果表明,当药芯粉中加入质量分数为1.5%的NaF作为稳弧剂时,焊接过程最稳定,产生的焊接飞溅最少且以小颗粒飞溅为主;优化后的焊丝堆焊获得的堆焊层表面无焊接缺陷;堆焊层金属主要为马氏体,硬度高于锻造5CrNiMo热作模具钢;在600℃高温环境下,堆焊层金属强度与室温强度相当,高温稳定性好;堆焊层金属在600℃的磨损率比锻造5CrNiMo热作模具钢低18.75%,可用于模具钢的堆焊修复。The effect of NaF content on the stability of CO_2-gas shielding arc was studied by using high-speed photograph.The results show that the welding process can be improved by adding NaF into the flux-cored wire.While NaF content is added to 1.5%,the welding process is the best stable,which has the least spatter based on the small particles.The quality of deposited metal is high and welding defects is free on the top surface.Besides,the microstructures and mechanical properties were studied in this paper.The results show that the deposited metal has high hardness because of the high content of martensite and great stability at high temperature.There are few differences of yield strength and tensile strength while the experiments are carried on at the room temperature and 600 ℃.Compared to the as-forged 5CrNiMo steel,the deposited metal has better wear resistance.The experiments show that the wear rate of deposited metal is 18.75%,which is less than that of the 5CrNiMo forged at 600 ℃ and can be used to repair the die.

关 键 词：5Cr NI MO 热作模具 药芯焊丝 焊接工艺 堆焊层金属 

分 类 号：TG422.3[金属学及工艺—焊接]