【作者】 张国栋； 郑剑平； 张征；

【Author】 ZHANG Guo-dong;ZHENG Jian-ping;ZHANG Zheng;China Institute of Atomic Energy;

【机构】 中国原子能科学研究院反应堆工程技术研究部；

【摘要】 本文按照已定脉冲激光环形焊和高压堵孔焊工艺,采用扫描电子显微镜,能谱分析仪,氦质谱气密性检测,X射线无损检测,室温拉伸和显微硬度等测试设备和技术,研究了一种新型锆合金包壳管内压蠕变样品脉冲激光焊接头的显微组织和力学性能。结果表明,焊后试样密封性均优于8×10^-10 Pa m³/s,焊缝表面成形性良好,焊缝内部无气孔、裂纹和夹杂等焊接缺陷。环形焊缝室温拉伸均在母材一侧断裂,拉伸过程中焊缝无裂纹等缺陷产生,焊缝拉伸强度优于母材。脉冲激光高压堵孔焊缝形状为半球形,最小厚度为0.76 mm（大于母材壁厚）;焊缝组织明显分为3层,底部基体区为细小均匀等轴晶,中间过渡区为晶粒尺寸逐渐增大的等轴晶,顶部有效熔化区为粗大柱状晶。最后通过组织分析和硬度测试,解释了焊缝凝固过程对焊缝组织的影响。更多还原

【Abstract】 In this paper,pulse laser ring welding and high pressure hole-blocking welding process are used.The microstructure and mechanical properties of pulsed laser welding joint of a new type of zirconium alloy cladding tube were studied by means of scanning electron microscope,energy spectrum analyzer,helium mass spectrometry gas tightness test,X-raynondestructive test,tensile test at room temperature and microhardness test.The results showed that the tightness of the samples after welding was better than 8 × 10¹⁰ Pa m³/s,the surface of the weld had good formability,and there were no pores,cracks and inclusions in the weld.The annular weld was fractured on one side of the parent metal at room temperature.In the process of drawing,there are no cracks and other defects in the weld,and the tensile strength of the weld is better than the base metal.The shape of the high pressure hole plugging weld with pulsed laser is hemispherical with a minimum thickness of 0.76 mm（greater than the wall thickness of the parent metal）.The weld microstructure is obviously divided into three layers,the base area is fine and uniform equiaxed crystal,the intermediate transition area is equiaxed crystal with gradually increased grain size,and the effective melting area on the top is thick columnar crystal.Finally,the effect of weld solidification process on weld microstructure was explained by microstructure analysis and hardness test.更多还原