L80-3Cr耐腐蚀油井管管端开裂原因分析  

Analysis for End-cracking of L80-3Cr Corrosion-resistant Oil Well Pipe

作　　者：夏文斌[1] 赵映辉[1] 黄电源[1] XIA Wenbin;ZHAO Yinghui;HUANG Dianyuan(Hengyang Valin Steel Tube Co.,Ltd.,Hengyang 421001,China)

机构地区：[1]衡阳华菱钢管有限公司,湖南衡阳421001

出　　处：《钢管》2020年第5期52-55,共4页Steel Pipe

摘　　要：分析了热轧L80-3Cr油井管管端开裂的原因,认为:该热轧钢管管端开裂为脆性开裂;管端在除鳞过程中因冷却速度较快产生了大量脆性贝氏体组织,导致材料抵抗裂纹扩展的能力变差,而因冷却不均导致弯曲变形较大的钢管在矫直过程中会产生较大的残余应力,管端锯切不良时,残余应力会在释放过程中在管端毛边或豁口处集中,从而导致管端开裂。提出改进措施:热轧生产时,避免钢管端头因快速冷却产生大量脆性贝氏体组织;加强热轧过程管理,避免锯切或运输过程中产生的钢管端头毛边或尖锐的凹坑和豁口;对180-3Cr等韧性较差的合金钢种在热轧后24 h内进行热处理。The reasons for the end cracking of the hot-rol led L80-3Cr oil well pipe are analyzed.As a resultconclusion is made as follows.The pipe-end cracking is identified as a type of brittle cracking.Owing to rather highcooling speed as employed during the pipe-end de-scaling process,massive brittle bainite structure is developed,whichleads to poor crack propagation-resistance of the material.Furthermore during straightening process,rather high residualstress is produced with the pipe as remarkably bend-deformed due to inhomogeneous cooling.Thus in cased of bad sawingoperation,the residual stress,during releasing process,gathers at burs or breaks to eventually cause cracking of thepipe end.Accordingly improvement actions are proposed,i.e.,during hot rolling operation,trying as far as possible toavoid development of massive britle baimite structure as caused by fast cooling of the pipe-end;strengtheningmanagement of the hot-rolling process to prevent occurrence of any pipe-end burr or sharp pit and break as may happenduring the pipe sawing and conveying operations.Heat treatment has to be performed with in 24 h to pipes in any alloy typewith rather low toughness like L80-3Cr.

关 键 词：油井管 L8O-3Cr 脆性开裂 豁口 贝氏体组织 

分 类 号：TG3[金属学及工艺—金属压力加工]