HL级35CrMoA抽油杆杆体失效分析

为了研究分析某厂HL级35CrMoA抽油杆杆体失效原因,对失效抽油杆进行了宏观形貌观察和化学成分分析,并对其显微组织和断口形貌进行了分析和有限元计算。结果表明,该抽油杆的失效模式为典型的腐蚀疲劳断裂,显微组织主要为回火索氏体+铁素体;疲劳裂纹源于杆体表面腐蚀坑处,疲劳裂纹沿针状组织扩展;在拉伸载荷下,凸缘与杆体截面突变处应力水平相对较高,最终导致腐蚀疲劳失效。最后,提出了预防抽油杆失效的措施,为油田减少同类失效的发生提供重要的理论依据。

HL Grade 35CrMoA Sucker Rod Body Failure Analysis

In order to study the failure reason of HL grade 35CrMoA sucker rod body, the macroscopic observation and chemical composition analysis were conducted, and its microstructure and fracture morphology were analyzed and carried out finite element calculation. The result showed that the failure mode of the sucker rod was the typical corrosion fatigue fracture, and the microstructure mainly composed of tempered sorbite and ferrite;the fatigue crack derived from the corrosion pit of the sucker rod body surface, and the fatigue crack propagated along the acicular structure;under tensile load, the stress level was relatively high on the flange and the sucker rod body section mutation,eventually caused corrosion fatigue failure. Finally, the measures to prevent the failure of sucker rod were proposed, which will provide important theoretical basis for reducing the occurrence of the same kind of failure in oil field.