439铁素体不锈钢连铸坯中TiN夹杂物分布研究  

DISTRIBUTION OF TiN INCLUSIONS IN 439 FERRITE STAINLESS STEEL SLAB

作　　者：祝方义[1] 段豪剑 张立峰[2] 李实[1] 

机构地区：[1]宝钢不锈钢有限公司,上海200431 [2]北京科技大学冶金与生态工程学院,北京100083

出　　处：《上海金属》2014年第5期39-43,共5页Shanghai Metals

摘　　要：通过光学显微镜和扫描电子显微镜观测了439铁素体不锈钢连铸坯中TiN夹杂物的形貌,结果显示TiN夹杂物的形貌为近似规则的四边形并且在光学显微镜无偏光条件下,TiN夹杂物呈现为橙色。通过光学显微镜对连铸坯中TiN夹杂物分布进行统计研究,发现在连铸坯宽度方向的中部和1/4处,由内弧(或外弧),到内弧1/4处(或外弧1/4处),再到厚度方向中部,TiN夹杂物的尺寸增大而数量减少。这是由于连铸坯凝固过程中由外向内冷却速率减小,凝固坯壳的生长减慢,使得TiN夹杂物生长时间增加,而形核速率下降造成的。这与热力学计算得到的TiN夹杂物是在连铸坯凝固过程中形成的结论相吻合。在连铸坯宽度方向边部,由于冷却速率较大,凝固坯壳的快速生成,使得连铸坯中TiN夹杂物的尺寸分布和数量分布都没有明显的统计规律。TiN inclusion in 439 ferrite stainless steel slab was investigated by SEM-EDS and optical microscope.It was found that the morphology of TiN inclusions was approximate regular quad and appeared orange through optical microscope detection.At the center and 1/4 position of width direction,the quantity of TiN inclusions decreased while the average size of inclusions increased from loose side to the center.The reason was that TiN inclusions had a longer growing time and a slower nucleation rate due to the different cooling rate at different positions of the slab.The conclusion was identical to the thermomechanical calculation that TiN inclusions generated during solidification.There was no obvious regular pattern at the edge of width direction due to the high cooling rate and rapid generation of solidified shell.

关 键 词：439铁素体不锈钢 连铸坯 TiN夹杂物 分布 

分 类 号：TG14[一般工业技术—材料科学与工程]