旋转摩擦焊接头焊合机理研究  

Joint Formation Mechanism of Rotary Friction Welding Characterized by Seaming Ratio

作　　者：吕元召 李京龙[2] 李鹏[2] 孙涛[1] 熊江涛[1] 张赋升[2] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,西安710072 [2]西北工业大学摩擦焊接陕西省重点实验室,西安710072

出　　处：《材料研究学报》2017年第4期261-266,共6页Chinese Journal of Materials Research

基　　金：国家自然科学基金(51575451;51475376)~~

摘　　要：以Q235低碳钢为母材,研究了摩擦时间和顶锻压力对旋转摩擦焊接头焊合率和冶金质量的影响规律并分析了接头焊合机理。结果表明,不同焊接参数下已焊合区域的拉伸强度基本相同且均大于或等于母材强度,焊接参数影响的只是接头焊合率(焊合率:接头横截面焊缝焊合部分长度与总长度之比),因此提出将焊合率作为焊接质量的评价标准。进一步研究表明,在其他参数不变的情况下,焊合率随顶锻压力的增大而增大,但增大速率逐渐趋缓,当顶锻压力达到某临界值后,焊合率达到100%,对所需临界压力进行了分析并得出了其计算方法;随着摩擦时间的增加,轴向缩短量增大,焊合率减小,焊接界面温度升高,高温区变宽,焊后再结晶区域加宽且晶粒尺寸变大。近缝区组织呈流线状,且晶粒大小不均匀。最终得出,大顶锻压力,短摩擦时间有助于提高焊合率,减小晶粒尺寸小,提升接头整体质量。Weld joints of low carbon steel Q235 was prepared by rotary friction welding technique, and the effect of friction time and forge pressure on the seaming ratio and metallurgical quality of weld joints was investigated. The results show that the tensile strength of the seaming zones prepared by the rotary friction welding with different welding parameters is greater than or equal to that of the base metal, in other word, the variation of welding parameters will simply affect the seaming ratio （the ratio of the length of seamed portion to the total length of a joint）, while the quality of joints is direct determined by the seaming ratio. Further study shows that the seaming ratio increases with the forging pressure, but the increment slows down gradually and eventually reaches 100% when the forging pressure reaches a critical value. The axial shortening amount increases along with friction time, which then decreases the seaming ratio. The width of the weld zone becomes larger and the grain size increases with friction time. The grain size is not uniform near the weld seam with streamline structure presented. It is concluded that large forging pressure and short friction time are helpful to improve the seaming ratio, reduce the grain size and enhance the quality of the joints.

关 键 词：金属材料 焊合机理 旋转摩擦焊 焊合率 接头质量 

分 类 号：TG453[金属学及工艺—焊接]