梁板钢板坯角部横裂纹控制技术的研究

针对攀钢V和V-Nb微合金化低碳梁板钢200 mm连铸坯出现角部横裂纹缺陷,通过综合优化连铸工艺参数-将结晶器铸坯窄宽面热流比由原先的0.90～1.10降至0.75～0.85,保护渣的粘度由0.20 Pa ? s降至0.16 Pa ? s,稳定连铸拉速和连铸机工况条件,使铸坯角部横裂纹缺陷得到了明显改善,并消除了由此引起的热轧饭卷表面线纹和起皮缺陷,因梁板钢热轧板卷表面缺陷引起的降级改判率由30%降至0。

A Study on Control Technology for Transverse Corner Cracks of Concasting Slab of Auto Frame Steel

According to transverse corner cracks occurred on 200 mm casting slab of V or V-Nb microalloying low carbon auto frame steels produced at Pangang Steel, with coniprehensive-optimized casting process parameters including decreasing the ratio heat flux between nan'ow side and broad side of slab in mold from original 0. 90 ~ 1. 10 to 0. 75 ~ 0. 85, decreasing the mold powder viscosity from 0. 20 Pa ? s to 0. 16 Pa ? s, stabilizing the casting speed and working condition of caster, the casting slab transverse corner crack defects significantly reduce and the hot rolled coil lines and peeling defects caused by the transverse corner cracks of slab are eliminated, therefore the percentage of changing criterion or reducing to lower grade caused by surface defects of auto frame steel hot rolled coil decreases to 0 from original 30%.