12Cr1MoVG钢管内表面环形裂纹缺陷原因分析及改善研究  

Analysis and Improvement of Annular Crack Defect on Internal Surface of 12Cr1MoVG Steel Pipe

作　　者：马金辉 蔡亮 朱志宝 李刚 张银桥 陈国生 闵杰 MA Jinhui;CAI Liang;ZHU Zhibao;LI Gang;ZHANG Yinqiao;CHEN Guosheng;MIN Jie(Daye Special Steel Co.,Ltd.,Huangshi 435001,China)

机构地区：[1]大冶特殊钢有限公司,湖北黄石435001

出　　处：《钢管》2024年第5期43-46,共4页Steel Pipe

摘　　要：对大规格12Cr1MoVG连铸圆坯轧制的钢管内表面出现的环形裂纹缺陷进行金相及电镜观察,未发现大型夹杂,裂纹缝内氧化铁厚实,部分呈颗粒状,缝内高温内氧化点聚集,缝侧脱碳明显。通过轧制试验研究发现,钢管内表面环形裂纹缺陷是连铸坯心部V型缩孔经穿孔轧制所致。通过优化连铸拉坯速度、电磁搅拌强度、管坯加热温度和穿孔轧制方向等可以消除钢管内表面的环形裂纹缺陷。The annular crack defect occurs on the inner surface of the rolled seamless steel pipe as made of the largesized 12Cr1MoVG CC round billet.The defect is observed by the metallographic microscope and the scanning electron microscope,and no large inclusions are found,the iron oxides as found in the crack are thick,and some are in granular form.High temperature inner oxidation points gathered in the crack defect,and decarburization is obvious on both sides of the crack.Thanks to the research via the pipe-rolling experiment it is identified that the annular crack defect on the inner surface of the steel pipe is caused by the V-shaped shrinkage hole in the core of the CC round billet during the piercing process.Therefore the said annular crack defect on the inner surface of the steel pipe can be eliminated by means of optimizing the process of the CC billet drawing speed,the electromagnetic stirring strength,the billet heating temperature and the piercing direction.

关 键 词：无缝钢管 内表面环形裂纹 12CR1MOVG 连铸圆坯 

分 类 号：TG115[金属学及工艺—物理冶金] TG335[金属学及工艺—金属学]