900 MPa级无缝钢管纵向开裂失效分析  

Failure analysis of longitudinal cracking of 900 MPa seamless steel pipe

作　　者：邝兰翔 刘冬 姚中海 杜丽影 KUANG Lanxiang;LIU Dong;YAO Zhonghai;DU Liying(R&D Center of Wuhan Iron&Steel Co.,Ltd.,Baosteel Central Research Institute,Wuhan 430080,China)

机构地区：[1]宝钢股份中央研究院武钢有限技术中心,湖北武汉430080

出　　处：《物理测试》2023年第6期43-49,共7页Physics Examination and Testing

摘　　要：某900 MPa级无缝钢管在钻探过程中发生开裂现象。通过化学成分、力学性能和金相组织分析,未发现与产品出厂性能有差异,非产品组织异常、成分偏差或性能偏低引起的质量问题。在此基础上,采用有限元仿真分析了管体受力状况,并使用X射线残余应力分析仪测量钢管表层及不同深度层的残余应力,对使用过程中开裂的原因进行了进一步的分析。结果表明:钢管服役工况切应力在100 MPa以上。残余应力最大值均出现在浅表层约1 mm深度处,最大达784 MPa。浅表层高值残余应力是导致钢管生产完毕后在浅表层局部区域产生毛细小裂纹的主要原因,后期在用户使用过程中外加载荷叠加残余应力导致这些毛细小裂纹二次扩展形成多裂纹源开裂的主裂纹,最终形成钢管纵裂。A 900 MPa seamless steel pipe experienced cracking during the drilling process.Through analyses of chemical composition,mechanical properties,and metallographic structure,no differences were found between the factory performance of the product.This failure was not caused by the structure abnormalities,component deviations,or low performance.On this basis,the finite element simulation was used to analyze the stress status of the pipe body,and an X-ray residual stress analyzer was used to measure the residual stress on the surface layer and different depths of the steel pipe.The reasons for cracking during use were further analyzed.The results indicated that the shear stress of steel pipes under service conditions was above 100 MPa.The maximum residual stress values all occurred at a depth of approximately 1 mm in the shallow layer,with a maximum of 784 MPa.The high residual stress in the shallow surface layer was the main reason for the formation of capillary and small cracks in local areas of the shallow surface layer after the production of steel pipes was completed.In the later stage of use,the combined action of external load and residual stress led to the secondary propagation of these small cracks,forming the main crack with multiple crack sources,and ultimately causing the longitudinal crack of the steel pipe.

关 键 词：无缝钢管 残余应力 有限元 开裂 

分 类 号：TG115[金属学及工艺—物理冶金]