By using spectrum analyzer,optical microscope and SEM,chemical composition and microhardness of tube material were tested,and metallurgical structure and fracture pattern of the joint were observed.

• 利用光谱分析仪、光学显微镜和扫描电镜等测试手段,测试了炉管材料的化学成分和显微硬度,观察了失效接头的金相组织和断口形貌。