Abstract: In order to improve the shrinkage cavity, loose and segregation defects of the slab, Hesteel Tangsteel has been built and put into production the first wide slab continuous casting production line with heavy reduction. The influence of different reduction on the internal quality of continuous casting billet is analyzed by means of acid pickling and original position analysis. The test results show that with the amount of reduction is increased from 0 mm to 24mm, the center segregation of continuous casting slab gradually weaken, central segregation grade is only C0.5 under 24mm, by metallographic examination, the grain size of the surface and center of the billet can be refined under heavy reduction, by original position analysis found that compared with soft reduction, the maximum segregation degree of C element is reduced from 1.355 to 1.193, the maximum segregation degree of S element is reduced from 3.772 to 1.631, the maximum segregation degree of P element is reduced from 2.246 to 1.336. These result indicated that heavy reduction is an effective technology to realize high density, homogeneous large section billet production.
Authors: Wei Guang-yun， Li Shuang-jiang， Li Jian-xing, Chang Jinbao, and Su Li
Keywords: heavy reduction; center segregation; center porosity; slab