(1. 山东大学 材料液固结构演变与加工教育部重点实验室,济南 250061;
2. Department of Materials Science, Bauman Moscow State Technical University, Moscow 105005, Russia)
摘 要: 采用填丝钨极氩弧焊(TIG)方法对复层厚度仅为0.3 mm的Super-Ni叠层复合材料与18-8不锈钢进行焊接试验。焊后对焊缝的微观组织及显微硬度、熔合区附近元素分布等进行分析。结果表明:叠层复合材料与焊缝形成可靠的熔合,Super-Ni复层侧熔合区附近的显微硬度升高(HM190);18-8不锈钢侧焊缝的显微硬度低于不锈钢母材的,不锈钢热影响区的显微硬度最高(290 HM);不锈钢一侧热影响区形成δ铁素体和碳化物析出;母材与焊缝间形成Fe与Ni元素的明显过渡,叠层复合材料侧元素过渡区域的宽度为80~85 μm,18-8不锈钢侧元素过渡区域的宽度约为20 μm;焊接中应使钨极氩弧偏向18-8不锈钢一侧,以避免Ni复层的过度烧损。
关键字: 叠层复合材料;钨极氩弧焊;显微组织;元素分布;熔合区
super-Ni laminated composite and 18-8 steel TIG joint
(1. Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education,
Shandong University, Ji’nan 250061, China;
2. Department of Materials Science, Bauman Moscow State Technical University, Moscow 105005, Russia)
Abstract:Super-Ni laminated composite (with 0.3 mm-thick cover layer) and 18-8 stainless steel were welded with filler alloy by tungsten inert gas welding (TIG). The microstructure, microhardness and element distributions in the welding zone were analyzed. The results show that a valid connection forms between the laminated composite and the weld metal, the microhardness (190 HM) near the fusion zone of Super-Ni cover layer side increases. The microhardness of the welding seam region on 18-8 steel side is lower than that of the base metal, and the highest microhardness (290 HM) appears in the heat-affected zone (HAZ) of 18-8 steel. δ ferrite and carbide phase form on the HAZ of 18-8 steel side. The transition of Fe and Ni elements obviously occurs between the base metal and the weld, with 80−85 μm-wide transition zone near the laminated composite side and about 20 μm-wide transition zone near the 18-8 steel side. In the welding process, the welding tungsten arc should be controlled towards the 18-8 steel side to avoid excessive melting loss of the Ni cover layer.
Key words: laminated composite; tungsten inert gas welding; microstructure; element distribution; fusion zone