论文部分内容阅读
采用自动扫描电镜Aspex研究了超纯铁素体不锈钢B439M(/%:0.01C,0.40Si,0.25Mn,0.020P,0.001S,17.50Cr,0.15Ni,0.20Ti,0.0080N,0.0040O)200 mm×1 260 mm连铸板坯中TiN夹杂物的分布,结果表明,由于连铸坯凝固过程中由外向内冷却速率减小,在连铸坯宽度方向边部,生成了大量小尺寸(平均1.26μm)TiN夹杂物;而在连铸坯宽度方向的1/4处和中部,由内弧表面到厚度1/4处再到厚度方向中部,TiN形核速率降低,TiN夹杂物的数量减少而尺寸增大。动力学分析结果得出,冷却速率减小会使得TiN夹杂物的生成尺寸增大,与TiN夹杂物在连铸坯中的分布规律相吻合。
Ultrapure ferritic stainless steel B439M (/%: 0.01C, 0.40Si, 0.25Mn, 0.020P, 0.001S, 17.50Cr, 0.15Ni, 0.20Ti, 0.0080N, 0.0040O) 200 mm × 1 260 mm The distribution of TiN inclusions in the continuous casting slab shows that due to the decrease of the cooling rate from the outside to the inside during the slab solidification, a large number of small size (average 1.26 μm) TiN inclusions. However, the nucleation rate of TiN decreases and the number of TiN inclusions decreases at the ¼ and the middle of the slab in the width direction from the inner arc surface to the thickness of 1/4 and then to the middle of the thickness. Size increases. The kinetic analysis results show that the decrease of cooling rate will increase the size of TiN inclusions, which is consistent with the distribution of TiN inclusions in the slab.