Abstract: The 150 mm×150 mm billet of carbon and alloy constructional steel,high carbon steel and welding rod  steel casts by R9 m 4 strand concaster at Shiheng Special Steel Works. Through optimized secondary cooling process modified 0.5~0.8 MPa water pressure,0.80~1.30 L/kg water ratio and 3 section manual water cooling process to 0.20～0.30 MPa water pressure,0.25～0.75 L/kg and automatic(water + gas)- water cooling process, the middle crack and bulging defects were eliminated and the rhomboidity,dispersed shrinkage and shrinkage cavity defects decreased by 50%～80%.

Key words: 150 mm×150 mm Billet Concasting,Secondary Cooling,Processing Optimization

摘要： 石横特钢厂由R9 m 4机4流连铸机连铸150 mm×150 mm碳素和合金结构钢、高碳钢和焊条钢。通过优化二冷段工艺,将0.5~0.8 MPa水压、0.80~1.30 L/kg比水量和3段手动水冷工艺分别改成0.20~0.30 MPa水压、0.25~0.75 L/kg比水量和4段自动(水+气)水冷工艺后,杜绝了中间裂纹和鼓肚缺陷,并使脱方、缩孔、疏松缺陷降低了50%~80%。

关键词: 150 mm×150mm 方坯连铸, 二次冷却, 工艺优化