82B小方坯生产工艺优化

Optimization of 82B billet production process

82B盘条制作钢绞线出现拉拔断丝。通过对炼钢连铸生产工艺进行分析,拉拔断裂原因主要是铸坯存在中心偏析、疏松和缩孔,铸坯内部存在非金属夹杂物,成分中氮含量高等。通过优化连铸生产工艺,控制小方坯连铸生产82B高强度钢绞线用钢的钢水过热度在15~25℃、连铸拉速1.8 m/min、冷却强度采用超弱冷等基本工艺参数以及采用电磁下渣检测技术,使82B小方坯中心碳偏析指数降低为1.02~1.05,缩孔1级所占比例提高到96.8%,盘条气体氮质量分数平均值为45×10-6。经实际生产验证,82B盘条的各项性能得到改善和提高。

Wire drawing breakage occured while steel strand was produced by 82B wire rod.Steelmaking and continuous casting production process was analyzed,main causes of drawing fracture are central segregation,porosity and shrinkage cavity,presence of non-metallic inclusions in billet,and high nitrogen content in composition.By optimizing continuous casting process,controlling basic technological parameters such as overheat of molten steel 15~25℃,casting speed 1.8 m/min,ultra-weak cooling of cooling strength and detection technology of electromagnetic slag in production of 82B high strength steel strand by billet caster,carbon segregation index at center of 82B billet reduced to 1.02~1.05,proportion of shrinkage hole 1 grade increased to 96.8%,and average nitrogen content in wire rod is 45×10-6.The actual production shows that performance of 82B wire rod is improved.