摘要
采用激光焊对壁厚0.5 mm的钼管和作为端塞的钼棒进行了焊接试验,借助光学显微镜(OM)、扫描电镜(SEM)及拉伸试验机,研究了预热温度对焊接接头组织及性能的影响。结果表明,随着预热温度的升高,焊缝熔化区晶粒尺寸逐渐增大,焊缝区氧元素的含量呈先降低后升高的变化趋势且在预热温度为400℃时氧元素含量最低,焊接接头的强度则先升高再降低且也在预热温度为400℃时达到最高。不同预热温度的激光焊接接头拉伸时均沿焊缝中心线发生沿晶脆性断裂;预热降低了焊接的应力,改善了接头内部氧元素的分布进而降低了接头的脆性,从而有效提高了焊接接头的强度。
Laser welding was used to conduct welding experiments on the molybdenum tube with wall thickness of 0.5mm and the molybdenum rod as an end plug. With the aid of an optical microscope(OM), scanning electron microscope(SEM)and tensile testing machine, the effect of preheating temperature on the structure and properties of the welded joints were studied. The results show that with the preheating temperature increasing, the grain size of the weld melting zone gradually increases, and the oxygen content in the weld zone first decreases and then increases;when the preheat temperature is 400 ℃,the oxygen content is the lowest;the strength of the welded joint first increases and then decreases, and also reaches the highest when the preheating temperature is 400 ℃. The laser welded joints under different preheating temperatures are all intergranular brittle fracture along the weld centerline during tensile test. Preheating reduces the stress of welding, improves the distribution of oxygen element in the joint and reduces the brittleness of the joint, thereby effectively improves the strength of the welded joint.
作者
刘东新
安耿
刘仁智
席莎
张林杰
杨程
LIU Dongxin;AN Geng;LIU Renzhi;XI Sha;ZHANG Linjie;YANG Cheng(Technical Center,Jinduicheng Molybdenum Co.,Ltd.,Xi'an 710077,China;State Key Laboratory for Mechanical Behavior of Materials,Xi'an Jiaotong University,Xi'an 710049,China;School of Metallurgical Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China)
出处
《热加工工艺》
北大核心
2022年第13期137-140,共4页
Hot Working Technology
基金
陕西省重点研发计划项目(2018ZDXM-GY-120)
陕西省科技重大专项项目(2020zdzx04-02-01)。
关键词
预热
钼薄壁管
激光焊
显微组织
拉伸性能
preheating
molybdenum thin-walled tube
laser welding
microstructure
tensile property
