X95钢级钻杆管体外表面裂纹形成原因分析  

Investigation on Elements Responsible for Development of External Surface Cracks of Drill Pipe Body in Steel X95

作　　者：赵映辉[1] 丁毅[2] 李平全[1] 张国正[1] 张春婉[1] 

机构地区：[1]西安摩尔石油工程实验室,陕西西安710065 [2]塔里木油田物资采办事业部,新疆库尔勒841000

出　　处：《钢管》2009年第5期43-47,共5页Steel Pipe

摘　　要：一批钢级为X95的钻杆,在进行钻杆接头摩擦对焊和钻杆管体内表面涂层涂覆处理后,探伤时发现部分钻杆管体存在不同程度的纵向裂纹。通过金相、扫描和能谱分析的手段,对裂纹的形貌和形成原因进行分析,并结合生产工艺过程,对产生裂纹的原因进行追溯。结果表明:钻杆管端磁粉探伤时与电极接触,管体局部粘附了低熔点电极材料,造成了重金属污染,在后续的加工过程中,管体再次受热,粘附其上的重金属元素向管体金属沿着晶界扩散,从而导致了裂纹的形成。Longitudinal cracks with different severity are found via non-destructive flaw detection in some drill pipe bodies from an X95 lot as having undergone joint friction welding and internal surface coating. The morphology of and causes for the said cracks are analyzed by means of such methods as metallography,SEM and EDS. Furthermore,causes for the cracks are traced based on the manufacturing process. As a result,it is identified that the said cracks are caused due to such facts that some low melting point electrode material sticks to the external surface of the pipe body which results in certain heavy metal pollution, when the pipe body contacts the electrode during the pipe-end magnetic particle examination operation, and that in the processing operations as follow, the pipe is reheated, and consequently, the heavy metal elements spread along the grain boundary, which eventually leads to the development of the cracks.

关 键 词：钻杆 磁粉探伤 重金属污染 裂纹 

分 类 号：TG142.15[一般工业技术—材料科学与工程]