45钢连铸大方坯中心疏松与缩孔控制  

Control countermeasures of center porosity and shrinkage in 45 steel continuous casting bloom

作　　者：陈亮[1,2] 宋波[1] 陈天明[2] 陈雄 杨文中 CHEN Liang;SONG Bo;CHEN Tian-ming;CHEN Xiong;YANG Wen-zhong(School of Metallurgyical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;Pangang Group Research Institute Co.,Ltd.,Chengdu 611731,Sichuan,China;Pangang Group Panzhihua Steel and Vanadium Co.,Ltd.,Panzhihua 617022,Sichuan,China)

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]攀钢集团研究院有限公司,四川成都611731 [3]攀钢集团攀枝花钢钒有限公司,四川攀枝花617022

出　　处：《钢铁》2018年第8期49-54,共6页Iron and Steel

摘　　要：针对360 mm×450 mm断面的45钢连铸坯中心疏松和缩孔导致轧制后圆钢探伤不合格的问题,开展了拉速与二冷水对比试验、凝固末端电磁搅拌对比试验以及重压下压下辊辊型对比试验,采用低倍酸洗、原位分析和真密度分析了试验铸坯和轧制后圆钢质量。试验结果表明,采用拉速0.45 m/min、二冷采用中冷、凝固末端电磁搅拌采用300 A/2.4 Hz时有利于铸坯扩大铸坯等轴晶区,铸坯等轴晶区最大为280 mm×170 mm。重压下采用凸形辊生产的铸坯中心真密度为8.022 6 g/cm3,致密度为0.998 4,高于平辊重压下。综合技术应用后,累计生产45圆钢2 583 t,45圆钢探伤合格率从70.85%提高到95.87%。In order to reduce the rate of flaw detection disqualification in 45 round steel with diameters from ？200 mm to Ф250 mm which was rolled in 360 mm×450 mm bloom. The main causes of flaw detection disqualification were center segregation and porosity of blooms. The casting speed,secondary cooling water and electromagnetic stirring at end of solidification were contrast tested. The roller of heavy reduction was optimized. Microscopy,scanning spectrometer and true density of the blooms were analyzed. The results show that the 0.45 m/min casting speed and low secondary cooling water with 300 A and 2.4 Hz parameters of electromagnetic stirring were benefit to the equiaxed grains expanding. The biggest area of equiaxed grains was 280 mm×170 mm.The true density and compactness of bloom with convex roller were 8.022 6 g/cm3 and 0.998 4 respectively which was higher than that in flat roller. After comprehensive technology application,the qualification rate of flaw detection was improved form from 70.85% to 95.87% in 2 583 tons 45 round steel production.

关 键 词：大方坯 连铸 拉速 二冷水 电磁搅拌 重压下 

分 类 号：TF777[冶金工程—钢铁冶金]