鋼塊の初期凝固層におけるCrとNiの偏析
1990 年 76 巻 5 号 p. 722-727
詳細
1990 年 76 巻 5 号 p. 722-727
18-8 stainless steel ingots were made with water cooled copper mold under four Reynolds number conditions. The existence of the initial solidification layer near surface of the ingot was verified. In the initial solidification layer, primary structure consisted of austenitic cells. In the initial cell region, concentration of Cr was high and that of Ni was low. Contrary to it, in the residual δ-ferrific intercell region, concentration of Cr was low and that of Ni was high. Result of segregation measurement of Cr and Ni in the initial solidification layer was opposite to that at conventional solidification. At the boundary of the initial solidification layer, transformation of primary structure from austenite to δ-ferrite occurred. At the boundary of the initial solidification layer, the peak value of segregation ratio(C max/C min ) appeared. Segregation of Cr and Ni was larger under the low Reynolds number condition and increased as the distance from surface increased. Segregation ratio of Ni was larger than that of Cr.
