厚规格调质高强度船板心部冲击不合格原因分析  

Cause analysis of unqualified impact at the center of thick quenched and tempered high strength ship plate

作　　者：王孝东 余宏伟 张开广 鲍海燕 张欢 易勋 WANG Xiaodong;YU Hongwei;ZHANG Kaiguang;BAO Haiyan;ZHANG Huan;YI Xun(Baowu Group Echeng Iron and Steel Co.,Ltd.,Ezhou 436002,China;Research and Development Center of Baosteel lron and Steel Co.,Ltd.,Wuhan 430080,China)

机构地区：[1]宝武集团鄂城钢铁有限公司,湖北鄂州436002 [2]宝武集团中央研究院,湖北武汉430080

出　　处：《物理测试》2021年第3期48-52,共5页Physics Examination and Testing

摘　　要：为找出厚规格调质高强度船板心部冲击不合格的原因,通过光谱仪、显微镜、SEM-EDS能谱仪等仪器,对心部试样的成分、组织进行分析,结果表明:心部冲击不合格的原因是中心偏析带上存在大尺寸MnS夹杂与Nb、Ti的夹杂物,以及较多Al2O3夹杂和Mg、Ca等外来夹杂物。分析认为,通过提高钢水洁净度,避免钢水二次氧化污染,控制钢包炉(LF)精炼周期与操作,降低钢水过热度,优化电磁搅拌和轻压下工艺,采用堆垛缓冷等措施,可以提高铸坯内部质量,减少中心偏析和夹杂,同时通过适当优化铸坯加热、轧制及热处理工艺,可以有效提高心部冲击韧性。In order to find out the reason of unqualified impact at the center of thick quenched and tempered high strength ship plate,the composition and microstructure of the core sample were analyzed by means of spectrometer,microscope and SEM-EDS.The results showed that the reason for the unqualified impact at the center was the presence of large-size MnS inclusions,Nb and Ti inclusions,as well as more Al2O3 inclusions and Mg,Ca and other foreign inclusions.The analysis suggested that,through the measures such as improving the cleanliness of molten steel,avoiding secondary oxidation pollution,controlling ladle furnace(LF)refining cycle and operation,reducing the degree of superheat of molten steel,optimizing the electromagnetic stirring and soft reduction process,and adopting the slow cooling for stacking,the internal quality of the slab could be improved,and meanwhile,the central segregation and inclusions could be reduced.At the same time,the core impact toughness could be effectively improved by properly optimizing the slab heating,rolling and heat treatment process.

关 键 词：调质高强钢 冲击 夹杂 中心偏析 

分 类 号：U671[交通运输工程—船舶及航道工程] TG142.15[交通运输工程—船舶与海洋工程]