37CrMnMo钻杆接头裂纹原因分析  

Analysis of Causes for Cracking of 37CrMnMo Drill Pipe Joint

作　　者：杨玭 曹晶晶[1] YANG Pin;CAO Jingjing(Shanghai Hilong Petroleum Tubular Goods Research Institute,Shanghai 200949,China)

机构地区：[1]上海海隆石油管材研究所,上海200949

出　　处：《钢管》2018年第5期33-37,共5页Steel Pipe

摘　　要：调质热处理后的某37CrMnMo钻杆接头,在磁粉检测时发现部分接头存在裂纹。为了查明该批钻杆接头裂纹产生的原因,对接头及裂纹处的化学成分、金相组织、力学性能及裂纹形貌等进行分析。分析结果表明:该批钻杆接头在锻造时,因中频感应加热炉加热的毛坯温度较高,使其出现严重的过热甚至过烧现象,造成合金元素沿晶界偏析与晶界弱化,而且在后续的热处理过程中未完全消除,从而在随后的调质过程中产生裂纹。建议生产时加强对锻造钻杆接头坯料化学成分的检验,严格监控钢坯的加热温度、保温时间,并合理选择工艺参数,以防止过烧,并提高产品质量。With the magnetic particle test cracks are found in some of the 37CrMnMo drill pipe joints of a certain lot as quenched and tempered. In order to identify the causes for the cracking, the joints and crack-beating parts of the joints are analyzed in terms of chemical composition, metallographic structure, mechanical properties and crack morphology, etc. As a result, the following reasons for the cracks are identified. Before forged, temperature of the joints as heated in the MF induction furnace is so high that they are overheated, and even over burnt, resulting in the alloy element segregation along the grain boundary, and grain boundary weakening which are not fully eliminated in the subsequent heat treatment process so as to get cracks produced during the quench-temper process as follows. Accordingly, necessary measures are proposed, including strengthening in-process inspection of the chemical composition of the drill pipe joint as forged, strictly monitoring the heating temperature and soaking time of the steel blank, and properly determining the process parameters so as to prevent over-burning of the joint, and improve the quality thereof.

关 键 词：钻杆接头 裂纹 过热 过烧 晶界弱化 

分 类 号：TG113[金属学及工艺—物理冶金]