摘要
针对Φ200 mm 37Mn5钢圆坯高拉速下铸坯存在的内部裂纹、中心缩孔与中心疏松等缺陷,结合生产实际分析得出过热度高、结晶器电磁搅拌强度偏小、二冷工艺及喷嘴布置不合适是引起铸坯质量问题的主要原因。通过建立经射钉及测温试验验证的凝固传热模型与采用高斯计测量电磁搅拌磁场的分布特征分别对二冷工艺制度和结晶器电磁搅拌参数进行优化,同时对二冷区喷嘴布置进行改进。结果表明:对于Φ200 mm断面37Mn5钢连铸拉速从1.4 m/min提高到1.8 m/min,铸坯内部质量明显改善,内部裂纹消失,中心缩孔和中心疏松均为0.5级,若过热度大于30℃,仍存在比较严重的中心缩孔。
According to quality defects such as internal crack,center shrinkage and center porosity of37Mn5 steel round billet with high casting speed,the main reasons which lead to internal quality defects were high superheat,weak mold electromagnetic stirring intensity,unreasonable secondary cooling process system and arranging form of nozzles respectively based on analysis of production practice. Mathematical model of solidification and heat transfer verified by nail-shooting experiments and surface temperature testing was applied in optimizing secondary cooling process system. Stirring parameters were optimized by measuring the electromagnetic field distribution with Gauss meter in the mold at different stirring parameters,in addition arranging form of nozzles in second cooling zone was also improved. The results showed that Φ200 mm 37Mn5 steel round billet casting speed increased from 1. 4 m/min to 1. 8 m/min,the internal quality significantly has been improved. Internal cracks disappeared and the average grade of center shrinkage and center porosity was 0. 5,but when superheat was greater than 30 ℃,center porosity still existed.
作者
安航航
包燕平
王敏
王睿
AN Hanghang BAO Yanping WANG Min WANG Rui(State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China)
出处
《炼钢》
CAS
北大核心
2017年第4期39-45,共7页
Steelmaking
基金
国家自然科学基金项目资助项目(51404018)
关键词
37Mn5钢
圆坯
高拉速
内部质量
37Mn5 steel
round billet
high casting speed
internal quality
