焊接钢管弯曲测试试样断裂原因

Reasons for fracture of welded steel pipe bending test specimens

在对某S460M钢管进行焊接工艺评定的弯曲测试时,弯曲试样发生断裂。采用化学成分分析、力学性能测试、金相检验、扫描电镜及能谱分析等方法对弯曲试样的断裂原因进行分析。结果表明:断裂试样的焊缝及热影响区存在马氏体,断口附近存在大量非金属夹杂物,破坏了金属基体的连续性,在弯曲力的作用下,试样发生脆性断裂。

During the bending test for welding process evaluation of a certain S460M steel pipe,the bending specimen fractured.Chemical composition analysis,mechanical performance testing,metallographic examination,scanning electron microscopy,and energy spectrum analysis were used to analyze the cause of fracture in bending specimens.The results show that there was martensite in the weld seam and heat affected zone of the fractured specimen,and there were a large number of non-metallic inclusions near the fracture surface,which damaged the continuity of the metal matrix.Under the action of bending force,the specimen underwent brittle fracture.