Q355B直缝焊管开裂原因  

Cracking reason of Q355B straight seam welded pipe

作　　者：鞠芳 JU Fang(Lingyuan Iron and Steel Co.,Ltd.,Chaoyang 122504,China)

机构地区：[1]凌源钢铁股份有限公司,朝阳122504

出　　处：《理化检验（物理分册）》2024年第8期41-44,共4页Physical Testing and Chemical Analysis(Part A:Physical Testing)

摘　　要：某公司使用Q355B热轧带钢制作直缝焊管,焊接后发现部分焊管的焊缝区域发生开裂现象。采用宏观观察、金相检验、扫描电镜和能谱分析等方法研究焊管的开裂原因。结果表明:熔炼时带钢的硫化物含量较高,且连铸时带钢内弧1/4厚度处发生夹杂物偏聚现象,硫化物破坏了基体的连续性,在微裂纹处出现应力集中,最终造成焊管开裂。A company used Q355B hot rolled strip to make straight seam welded pipe.After welding,it was found that the weld area of some welded pipe cracked.The cracking reasons were researched by means of macroscopic observation,metallographic examination,scanning electron microscope and energy spectrum test.The results show that the sulfide content of the strip steel was high during melting,and the segregation of inclusions occured at the 1/4 thickness of the inner arc of the strip steel during continuous casting.The sulfide destroyed the continuity of the matrix,and the stress concentration occured at the micro-cracks,which eventually caused the cracking of the welded pipe.

关 键 词：焊管 开裂 硫化物 偏聚 应力集中 

分 类 号：TG115.2[金属学及工艺—物理冶金] TB31[金属学及工艺—金属学]