钻杆焊缝磁痕分析
Analysis of Magnetic Particle Indication on Welding Line of Drill Pipe
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摘要: 钻杆焊缝磁粉探伤出现磁痕是钻杆生产中的一种典型质量问题。分析了磁痕的特点和影响因素,对磁痕进行了金相观察和扫描电镜能谱鉴定,发现钻杆焊缝磁痕有条状和点状两种,靠近焊缝,与焊缝平行,出现在管体端距焊缝约5 mm内的环形条带状区域。分析认为,钻杆焊缝磁痕是钻杆管体中的夹杂物造成的,建议研究制定一个钻杆焊缝磁痕放行或判废的检验标准。Abstract: The magnetic particle induction occurred on the welding line of drill pipe is a typical quality problem during the drill pipe production. The characteristics of and influence factors on the magnetic particle indication on the welding line of drill pip are analyzed,metallographic observation is conducted and energy spectrum identification by scanning electron microscope is made. After above jobs it is found there are two kinds of magnetic particle indications on the welding line of drill pipe which are strip type and dot type,all adjacent and parallel to the welding line,appearing in a ring type belt area of pipe ends which is 5 mm away from the welding line. Analysis shows the magnetic particle induction occurred on the welding line of drill pipe is caused by the inclusions contained in drill pipe material therefore it is suggested a inspection standard for the magnetic particle induction on the welding line of drill pipe should be set up for judging which is accepted and which is rejected.