铅合金熔滴冲击45钢冷基板与45钢表面熔池的对比试验  

Comparative experiment between 45 steel cold substrate and molten pool on surface of 45 steel impacted by lead alloy droplet

作　　者：张永恒 杜军[1] 王勇超 魏正英[1] Zhang Yongheng;Du Jun;Wang Yongchao;Wei Zhengying(State Key Laboratory for Manufacturing System Engineering,Xi′an Jiaotong University,Xi′an 710049,China)

机构地区：[1]西安交通大学,机械制造系统工程国家重点实验室,西安710049

出　　处：《焊接》2022年第6期24-32,共9页Welding & Joining

基　　金：民用航天技术预先研究(D020208);江苏高校省级重点实验室开放研究课题(KJS1809);航空科学基金(20200054070001)。

摘　　要：针对特殊装备领域传统钢/铅粘接结构中存在的粘接层易老化脱落、长期稳定性差的问题,提出一种熔滴沉积复合TIG焊(gas tungsten arc welding)电弧增材制造新工艺,用于制造钢/铅双金属结构。文中比较性地研究了铅合金熔滴冲击铺展45钢冷基板与45钢表面熔池后的凝固形貌,通过引入无量纲数研究了熔滴冲击速度、温度对熔滴铺展凝固形貌的影响规律,利用OM,LSCM,SEM,EDS,XRD以及显微硬度测试等方法与手段,分析了熔滴沉积复合TIG电弧增材制造钢/铅双金属试样的界面微观组织结构与显微硬度。结果表明,铅合金堆积层铺展因子随熔滴冲击速度的增加呈明显非线性增加;界面层金属间化合物主要为FeSb;和FeSn_(2),其厚度随电弧热输入的增加而增加;钢/铅界面处的显微硬度明显高于铅合金堆积层和45钢母材;界面层中心左侧的硬度值达到最大值,为785.3 HV,45钢一侧平均硬度为343.7 HV,铅合金一侧平均硬度为24.3 HV。Aiming at the problems that the bonding layer was easily aging and peeling,poor long-term stability,and weak environmental adaptability in traditional steel/lead bonding structures in the field of nuclear weapons equipment,a new arc additive manufacturing process of droplet deposition composite TIG was proposed to manufacture steel/lead bimetallic structures.Solidification morphology of lead alloy droplets after impacting and spreading on 45 steel cold substrate and molten pool on surface of 45 steel was comparatively studied in this paper.Effects of impact velocity and initial temperature of droplets on solidification morphology of the impacted droplets were investigated by adopting dimensionless numbers.Interfacial microstructure and Vickers microhardness of steel/lead bimetallic specimens were analyzed by methods of OM,LSCM,SEM,EDS,XRD and hardness experiments.The results showed that spreading factor of lead alloy accumulation layer increased nonlinearly with the increase of impact velocity of droplets.Intermetallic compounds of interface layer were mainly FeSb_(2) and FeSn;,whose thickness increased with the increase of arc heat input.Vickers microhardness at the interface of steel/lead was significantly greater than that of lead alloy accumulation layer and 45 steel base metal.Hardness on the left side of interface layer center reaches the maximum value 785.3 HV,average hardness of 45 steel was 343.7 HV,and average hardness of lead alloy was 24.3 HV.

关 键 词：钢/铅双金属结构 熔融沉积成形 金属间化合物 显微硬度 

分 类 号：TG403[金属学及工艺—焊接]