Search International and National Patent Collections

1. (WO2014203937) CONTINUOUS CASTING METHOD FOR CAST SLAB

Pub. No.:    WO/2014/203937    International Application No.:    PCT/JP2014/066180
Publication Date: Thu Dec 25 00:59:59 CET 2014 International Filing Date: Thu Jun 19 01:59:59 CEST 2014
IPC: B22D 11/128
B22D 11/00
B22D 11/20
Applicants: NIPPON STEEL & SUMITOMO METAL CORPORATION
新日鐵住金株式会社
Inventors: WATANABE, Shinsuke
渡辺 信輔
MURAKAMI, Toshihiko
村上 敏彦
Title: CONTINUOUS CASTING METHOD FOR CAST SLAB
Abstract:
The main purpose of the present invention is to provide a continuous casting method for a cast slab, which satisfies the reduction of center segregation and center porosity and the suppression of surface cracks and inner cracks in the cast slab using a flat roll. The present invention is a continuous casting method for a cast slab, comprising: a step for forming a pair of parallel surfaces in a cast slab having a circular cross section and an unsolidified region therein by reducing the cast slab by cylindrical horizontal rolls; and a step for forming a pair of parallel surfaces perpendicular to the pair of parallel surfaces in the cast slab by reducing the completely solidified cast slab alternately by a roll pair of cylindrical horizontal rolls and a roll pair of cylindrical vertical rolls, wherein in the former step, the reduction rate of the cast slab by each of the roll pairs is more than 0.5% but less than or equal to 3%, and the ratio of the width of the unsolidified region in the cross section of the cast slab to the width of a contact portion between the cast slab and the rolls is 0-7.15, and in the latter step, the reduction rates of the cast slab by the horizontal rolls and the vertical rolls are 5.4-6.8%, respectively.