H62黄铜摩擦塞补焊接头微观组织及力学性能  

Microstructure and mechanical property of friction plug welded joint for H62 brass alloy

作　　者：张忠科[1] 初树晟 ZHANG Zhongke;CHU Shusheng(School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学材料科学与工程学院,兰州730050

出　　处：《材料科学与工艺》2024年第6期41-49,共9页Materials Science and Technology

基　　金：甘肃省科技重大专项项目(18ZD2GC013).

摘　　要：针对铜及铜合金的焊接缺陷,提出了利用摩擦塞补焊进行匙孔等缺陷补焊的一种有效方法,以实现铜类构件的原位修复。本文采用顶锻式摩擦塞补焊机对H62黄铜合金进行焊接,利用温度测试仪、光学显微镜、扫描电镜、拉伸试验机与硬度试验机对H62黄铜摩擦塞补焊接头进行温度、组织与力学性能分析,研究了4种不同主轴转速下接头性能之间的差异。研究表明:接头塞棒中心上层区域组织为晶粒细小的再结晶组织,下层组织为条状晶与再结晶晶粒组成的混合组织;各接头硬度均呈“W”形分布,塞棒中心处硬度最高,摩擦界面处硬度最低;接头峰值温度随主轴转速升高而升高,上、中、下3层温度差逐渐降低。同一主轴转速下接头摩擦界面处上层晶粒最细小,沿厚度方向向下晶粒尺寸逐渐增大;接头上层峰值温度最高,中层次之,下层最低。在主轴转速为2200 r/min时接头综合力学性能最佳,接头的抗拉强度为350.5 MPa,与母材的358.4 MPa等强,接头断裂方式为韧性断裂,在温度梯度与机械作用下,塞棒上层断口韧窝最为细小致密,表现出最优良的力学性能,下层断口表现出较差的塑性性能。Aiming to address welding defects in copper and copper alloys,an effective method is proposed for in-situ repair of copper components using friction plug welding to achieve keyhole and defect filler welding.A top forging type friction plug welding machine is used to weld H62 brass alloy in this study,the temperature profile,microstructure and mechanical properties of H62 brass friction plug joints are analyzed by temperature measurements,optical microscope,scanning electron microscope,tensile testing and hardness testing.The differences in the properties of the joint under four different spindle speeds were studied.The results show that the upper layer of the joint plug exhibits a fine recrystallization microstructure,while the lower layer consists of a mixed structure of columnar grains and crystallized grains.The hardness distribution of the joints shows a"W"-shaped,with the highest hardness at the center of the plug bar and the lowest hardness at the friction interface.The peak temperature of the joint increases with the spindle speed,while the temperature differene between the upper,middle and lower layers gradually decreases.The grain size of the upper layer at the friction interface of the joint is the smallest at the same spindle speed,and the grain size gradually increases downward along the thickness direction.The peak temperature is the highest in the upper layer of the joint,followed by the middle layer,and lowest in the lower layer.At a spindle speed of 2200 r/min,the joint exhibits the best overall mechanical performance.The tensile strength of the joint is 350.5 MPa,which is equal to 358.4 MPa of the base material.The fracture mode of the joint is ductile fracture.In addition,the upper layer of the plug bar fracture is the smallest and densest under the temperature gradient and mechanical action,showing the best mechanical properties,while the lower layer fracture shows poorer plasticity performance.

关 键 词：H62黄铜 摩擦塞补焊 主轴转速 显微组织 力学性能 

分 类 号：TG456[金属学及工艺—焊接]