摘要
通过化学成分、微观组织、断口形貌分析等方法对某管线建设中X80螺旋埋弧焊管环焊接头裂纹产生的原因进行了研究。结果表明,裂纹出现于对接焊缝焊趾处,呈现沿晶+穿晶的开裂形貌,属于焊接冷裂纹。焊接接头气孔、夹渣和焊接死口处拘束应力过高是裂纹产生的主要原因,焊接工艺不当是裂纹产生的直接诱因,焊接前对管径周向全尺寸进行预热是防止该裂纹产生的主要途径。
The cracking reason of X80 SAWH pipe circumferential welded joints in some pipeline construction was analyzed by chemical composition analysis, microstructure observation, and fracture morphology analysis. The results showed that, the crack, which appeared near butt weld toe of X80 SAWH pipe belongs to the welding cold crack, presents inter-granular and trans-granular cracking morphology. Welded joint hole, slag and much higher welding restraint stress are the main reason caused crack, and incorrect welding process is the direct reason. Full size circumferential preheating to steel pipe before welding is the principal method to prevent cracks.
出处
《焊管》
2012年第6期16-21,共6页
Welded Pipe and Tube
关键词
X80焊管
微观组织
环焊接头
焊接冷裂纹
X80 welded pipe
microstructure
circumferential welded joint
welding cold cracking
