石油钻杆材料G105在不同条件下的疲劳断裂  

Mechanism of Fatigue Fracture of G105 Drill Pipe Material Under Different Conditions

作　　者：黄本生[1] 陈想[1] 陈勇彬[1] 李永斌[2] 

机构地区：[1]西南石油大学材料科学与工程学院,成都610500 [2]辽宁省新民市沈阳采油厂,沈阳110316

出　　处：《材料工程》2016年第2期107-114,共8页Journal of Materials Engineering

基　　金：四川省教育厅重点项目(15ZA0057);石油天然气装备教育部重点实验室(西南石油大学)资助项目(OGE201402-02)

摘　　要：采用国产PQ-6型旋转弯曲疲劳试验机研究钻杆管体材料G105的弯曲疲劳性能以及H_2S腐蚀和缺口对试样弯曲疲劳性能的影响,利用金相显微镜和扫描电子显微镜对光滑试样断口、缺口试样断口以及H_2S腐蚀后试样断口进行微观形貌分析。结果表明:在光滑试样的疲劳极限载荷作用下,经过H_2S腐蚀后的光滑试样的疲劳寿命和缺口试样的疲劳寿命相当,材料的疲劳寿命都从106降低至104;缺口试样在缺口的高应力集中效应下,加快疲劳裂纹形核过程。H_2S腐蚀对钻杆疲劳性能影响的主要作用在于氢原子在材料内缺陷处聚集引起材料疲劳性能降低,缺口和H_2S腐蚀都会加快疲劳裂纹的扩展。材料疲劳断裂主要是因为试样在交变应力的作用下上产生滑移最后致使位错塞积而导致的。The bending fatigue fracture properties of G105 drill pipe body materials and the influence of H2 S corrosion and notch on the specimen bending fatigue performance were studied using the domestic PQ-6 type rotating bending fatigue testing machine. The fracture surfaces of smooth specimens, notched specimens and H2 S corroded specimens were analyzed using metallographie microscope and scan- ning electron microscope. The results show that under the stress of smooth specimens＇ ultimate fatigue loading, the fatigue life of specimens corroded by H2 S is same as that of notched specimens, declining from 106 to 104. The high stress concentration effect of notch can accelerate the process of fatigue crack nucleation in the notch specimen. The main role of H2S corrosion is that the hydrogen atoms will gather together at the inner defects, which will decrease the fatigue life. H2S corrosion and notch both can accelerate the propagation speed of the fatigue cracks. The main reason for the fatigue fracture of material is that the specimens under action of alternating stress engender slip, finally resulting in dislocation stacking.

关 键 词：G105钻杆钢 疲劳断裂 断口 滑移 

分 类 号：G105[文化科学]