P110级石油套管淬火组织形态对残余应力的影响  

Effect of Quenching Microstructural Morphology on Residual Stress of P110 Oil Casing

作　　者：李亚欣[1] 刘雅政[1] 洪斌[1] 朱洪武[1] 邹喜洋 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]衡阳华菱钢管(集团)有限公司技术中心,湖南衡阳421001

出　　处：《钢铁研究学报》2010年第8期55-59,共5页Journal of Iron and Steel Research

摘　　要：以降低P110级石油套管淬火冷却过程中的热应力和组织应力为目的,提出了水淬+空冷和水淬+空冷+水淬两种冷却方式。利用逐层钻孔法测试了不同工艺下的残余应力,分析了淬火组织特征和残余应力对裂纹产生和扩展的影响。结果表明:直接淬火工艺的淬火组织为板条马氏体和孪晶马氏体共存,且孪晶马氏体的含量较多。水淬+空冷和水淬+空冷+水淬两种工艺的淬火组织为板条马氏体、下贝氏体和不同程度的残余奥氏体,水淬+空冷+水淬工艺中还有少量孪晶马氏体。水淬+空冷、水淬+空冷+水淬两种冷却方式和直接淬火工艺相比,钢管内的切向和轴向残余应力均减小,从而易减小钢管的变形,以及降低和缓解了钢管内微裂纹的产生和扩展趋势。In order to reduce the thermal stress and structural stress of P110 oil casing in the process of quench cooling,water quenching＋air cooling and water quenching＋air cooling＋water quenching were proposed.The residual stress of different processes was determined by incremental hole drilling method and the effect of microstructural feature and residual stress on crack formation and propagation was analysed.The results show that the quenching microstructure of direct quenching technology consists of lath and twin martensite,and the amount of the latter is more.The quenching microstructure of water quenching＋air cooling and water quenching＋air cooling＋water quenching processes is composed of lath martensite,lower bainite and various amount of retained austenite.There are a few of twin martensite in the second technology.Compared to the direct quenching process,the tangential and axial stress of proposed cooling methods are both decreased,then the deformation of steel pipe is reduced and the trend of microcrack formation and propagation is relieved.

关 键 词：石油套管 冷却方式 组织形态 残余应力 

分 类 号：TG156.3[金属学及工艺—热处理]