Description
Abstract: Internal quality requirements of high grade pipeline steel slab is extremely strict. In this paper, the method for testing the internal quality has been reported. The causes of slab internal quality have been systematically analyzed . The results show that a large soft reduction rate inside the continuous casting machine segment is t he important factor to cause slab internal cracks. During the reduction segment, the internal cracks can be obviously controlled by uniform reduction technology. In addition, the relationship between internal segregation and the basic roll gap was investigated . Combined with the caster segment roll gap control positive deviation roll gap control before the soft pressure segment and negative deviation roll gap control in soft pressure segment were applied during the soft reduction process Consequently slab degradation rate owing to the central segregation of high grade pipeline steel decreased from 0.90% to 0, and percentage of slab intermediate cracks , which is less than 0.5 level increased from 73% to 100%
Authors: Guo-liang Liu, Qing Liu, Hai bo Li, Wen jun Ma, Bin Chen, Chen xi Ji, and Ke Liu
Keywords: Pipeline steel, Internal quality, In termediate crack, Segregation, Soft reduction