中碳钢连铸小方坯表面缺陷与保护渣性能选择

The Billet Surfaced Defects and Choice of Mould Fluxes Properties for Medium Carbion Steel by Continuous Casting Way

首钢第二炼钢厂160mm×160mm小方坯连铸使用高碳钢用FRK-45型保护渣生产碳含量为0．35％-0．50％的中碳钢时，大量连铸坯表面出现纵裂和横向凹坑。通过降低连铸机拉速、提高保护渣碱度及延缓保护渣熔速，改善了连铸坯坯壳与结晶器壁间的渣膜传热，使连铸坯的表面缺陷得到了有效控制。

When the FRK-45 mould fluxes for high carbon steel were used to produce the 0. 35% - 0. 50% medium carbon steel, a lot of surface longitudinal cracks and transverse pits were observed on the 160 mm × 160 mm billets which were produced by the No. 2 steelmaking plant of Shougang Group. Through reducing the casting rate, improving the basicity of mould fluxes, prolonging the dissolution rate of the mould fluxes and improving the thermal transfer between mould wall and billet shell, the surface defects could be effectively controlled.