摘要
采用金属原位分析仪、直读光谱仪、金相显微镜及电子探针显微分析仪检测了含0.064%、0.085%和0.101%C(质量分数)的低碳高强钢铸坯的中心偏析和带钢中的带状组织,目的是研究影响这种不良组织的因素从而采取改进措施。结果显示:低碳高强钢带钢中的带状组织与铸坯的中心偏析之间有很密切的关联性。中心偏析均存在于铸坯1/2厚度处,沿铸坯宽度方向的分布不均匀,即边部最轻,1/2宽度处次之,1/4宽度处最严重;带状组织在钢板中的分布与中心偏析在铸坯中的分布规律类似。碳和锰的平衡浓度分配系数不同以及铸坯在连铸过程冷却不均匀,是造成铸坯中心偏析的主要原因。通过降低含碳量、增加连铸过程中的电磁搅拌工序,可大大减少低碳高强钢铸坯的中心偏析;热轧加热对改善铸坯中碳的中心偏析效果较明显,但对改善磷的中心偏析几乎无效。
By means of in-situ-analyzer for metal,direct reading spectrometer,optical microscope and electron probe microanalyzer,the low-carbon high-strength steels containing 0.064%,0.085%and 0.101%C by mass were tested for center segregation in the cast slab and banded structure in the steel strip,for the purpose of investigating the factors exerting an influence on this type of undesired structure and thus adopting measures of reducing it.It was seen from the tested results that banded structure in the steel strip was dependent highly on center segregation in the cast slab,the center segregation existed in 1/2 thickness below surface of the cast slab,and exhibited uneven distribution in the cross section,being lightest on the edge,followed by in 1/2 width from the edge,and worst in 1/4 width from the edge.The distribution of the band structure in the steel plate was similar to that of the center segregation in the cast slab.The center segregation in cast slab stemmed mainly from difference in the equilibrium concentration distribution coefficient of the carbon and manganese and from the uneven cooling during continuous casting.The center segregation in cast slab of low-carbon high-strength steel would be greatly lessened by both reducing the carbon content and applying an electromagnetic stirring sequence during the continuous casting.The heating for hot-rolling could render center segregation of carbon obviously less,but was almost fail to improve center segregation of phosphor,in the cast slab.
作者
梁文
刘永前
胡俊
赵江涛
王立新
LIANG Wen;LIU Yongqian;HU Jun;ZHAO Jiangtao;WANG Lixin(Wuhan Branch of Baosteel Central Research Institute,Wuhan Hubei 430080,China;Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,Wuhan University of Science and Technology,Wuhan Hubei 430081,China)
出处
《上海金属》
CAS
北大核心
2019年第5期66-72,80,共8页
Shanghai Metals
基金
国家自然科学基金(No.51771139)
关键词
碳含量
中心偏析
带状组织
改进
措施
carbon content
center segregation
banded structure
improvement
measures
