20圆钢表面纵裂纹的成因分析  

Reason analysis of surface longitudinal cracks for 20 round bar

作　　者：王智轶[1] 王朝阳[1] 马立军[1] 贺建哲 

机构地区：[1]天津钢铁集团有限公司技术中心,天津300301

出　　处：《炼钢》2014年第4期33-35,41,共4页Steelmaking

摘　　要：为分析20钢连铸坯轧后表面线状裂纹成因,采用光谱分析仪、金相显微镜、扫描电镜及能谱仪分别对棒材裂纹处的化学成分、金相组织、显微形貌及夹杂物的类型进行分析。结果表明:20圆钢表面线状裂纹缺陷是由于连铸坯表面气孔引起的,铸坯表面气孔在轧制前加热过程中发生氧化进而轧制时不能被压合,轧制延伸时最终形成棒材表面线状裂纹缺陷。In order to find the causes of surface linear cracks in round bar rolled from 20 steel billet, spectrum analyzer, optical microscope, scanning electron microscopy and energy spectrum analysis were employed to examine chemical composition, microstructure of surface crack, type of inclusion in the cracks. The results show that cracks are caused by surface pores in 20 steel billet. Surface pores which are burned in rolling heating process are oxidized and can not be pressed. Surface linear crack defects are eventually formed in the process rolling extension.

关 键 词：裂纹 表面气孔 脱碳 氧化圆点 

分 类 号：TF761[冶金工程—钢铁冶金]