| 摘要 |
PROBLEM TO BE SOLVED: To prevent any longitudinal crack caused by the initial solidification phenomenon in a mold, in the continuous casting of sub-peritectic and low-alloy steel. SOLUTION: In the continuous casting method of hypo-peritectic and low-alloy steel, a vertical-bending type continuous casting machine is used. In the method, mold flux is used, which is basically composed of CaO, SiO<SB POS="POST">2</SB>, alkaline metal oxide, and fluorine, while basicity (CaO/SiO<SB POS="POST">2</SB>) as the mass-concentration ratio of CaO to SiO<SB POS="POST">2</SB>is≥1.6, the solidification point is≥1,250°C, and the viscosity at 1,300°C is≤1 poise. The specific water amount for secondary cooling is set to be≤0.20 liter/kg on the downstream side in the drawing direction of a cast slab from the mold, and at a vertical part on the upstream side in the drawing direction of the cast slab from a bending part. COPYRIGHT: (C)2013,JPO&INPIT |
