【关键词】 石油钻杆; 大型夹杂物; 裂纹; 分析; 措施; 【英文关键词】 Oil drill pipe; Large inclusion; Cracking; Analysis; Actions; 【摘要】 通过管体无损探伤检验和人工表面检验,并利用扫描电镜和能谱仪对石油钻杆缺陷试样进行微观检验,结果表明连铸坯大型夹杂物是导致钻杆裂纹的主要因素。根据钢管塑性变形理论分析了裂纹形成过程,提出了减少裂纹的措施。 【英文摘要】 The key element responsible for the cracking of the oil drill pipe is the large inclusion in the continuously cast billet. This conclusion is supported by the results of NDT detection and visual inspection of the pipe body and microstructure tests with the defective sample taken from the pipe by scanning electron microscope and energy spectrometer. The crack development process is also analyzed with the steel tube plastic deformation theory, and corrective actions are accordingly put forward.