37Mn5钢厚壁石油套管表面裂纹成因分析与控制  

Cause analysis and control of surface cracking of 37Mn5 steel thick-walled oil casing

作　　者：任芝兰[1] 唐明华[1,2] 毕红霞[1] 吴远志[1,2] 周勇[3] Ren Zhilan;Tang Minghua;Bi Hongxia;Wu Yuanzhi;Zhou Yong(School of Intelligent Manufacturing and Mechanical Engineering,Hunan Institute of Technology,Hengyang Hunan 421002,China;School of Materials Science and Engineering,Hunan Institute of Technology,Hengyang Hunan 421002,China;Technology Center,Hengyang Valin Steel Tube Group Co.,Ltd.,Hengyang Hunan 421001,China)

机构地区：[1]湖南工学院智能制造与机械工程学院,湖南衡阳421002 [2]湖南工学院材料科学与工程学院,湖南衡阳421002 [3]衡阳华菱钢管有限公司技术中心,湖南衡阳421001

出　　处：《金属热处理》2023年第7期277-282,共6页Heat Treatment of Metals

基　　金：湖南省衡阳市科技创新资助项目(200250045140)。

摘　　要：37Mn5钢厚壁石油套管在调质处理后发现表面裂纹,利用SEM、EDS及TEM等手段进行了裂纹成因分析和工艺改进试验研究。结果表明,钢管表面的裂纹是因为钢中非金属夹杂物、淬火应力集中和高温回火脆性等因素耦合作用的结果,夹杂物在轧制过程中诱发了微裂纹的产生,在淬火内应力的作用下微裂纹得到进一步扩展延伸,再加上高温回火脆性降低了材料的韧性,最终在钢管表面形成一定深度的宏观裂纹。石油套管采用改进的亚温淬火工艺处理后,可以在基本不降低材料强度的前提下,明显提高冲击韧性和抗断裂失效能力,抑制高温回火脆性,基本杜绝了表面开裂现象,取得了良好的生产应用效果。Surface cracks were found on 37Mn5 steel thick-walled oil casing after quenching and high-temperature treatment,the analysis of cracking causes and research of process improvement were carried out by means of SEM,EDS and TEM.The results show that the cracks on the surface of the 37Mn5 steel oil casing are because of multiple factors coupling such as non-metallic inclusions in the steel,quenching stress concentration and high-temperature tempering brittleness,inclusions induce micro-cracking during the rolling process,the micro-crack is further expansion and extension under the action of quenching internal stress,coupled with the high temperature tempering brittleness reduces the toughness of the material,eventually a certain depth of macro cracks are formed on the surface of the pipe.By using improved sub-temperature quenching process treatment,the impact toughness of the 37Mn5 steel oil casing is significantly improved and the resistance to fracture failure on the premise basically not reduce the strength of material,inhibits high-temperature temper brittleness,basically eliminating the surface cracking phenomenon,and achieving good production application results.

关 键 词：37Mn5钢 表面裂纹 亚温淬火 组织与性能 

分 类 号：TG162.7[金属学及工艺—热处理]