含硼中碳钢铸坯角部横裂纹影响因素分析  

Analysis on factors affecting slab surface transversal corner crack for boron bearing medium-carbon steel in continuous casting

作　　者：彭其春[1] 童志博[1] 于学森[1] 周春泉[2] 杨秀枝[2] 刘文华[2] 

机构地区：[1]武汉科技大学钢铁冶金及资源利用省部共建教育部重点实验室,湖北武汉430081 [2]湖南华菱涟源钢铁有限公司,湖南娄底417009

出　　处：《炼钢》2012年第6期44-48,共5页Steelmaking

摘　　要：基于含硼中碳钢A36-LB的生产实践,分析了钢水成分、钢中硼含量、振动曲线、结晶器水量、二冷制度及对弧、辊缝精度等对铸坯角部裂纹的影响,并提出了相应的控制措施,如控制钢水w(S)≤0.015%、w(Mn)/w(S)>37.6;w(Ca)/w(Als)>0.09;结晶器振动冲程减小1 mm,并提高振频使负滑脱时间降低32%左右;结晶器宽面和窄面水量稳定在4000和380 L/min,并采用弱冷冷却曲线、降低二冷水总水量,同时减少铸坯边部水量50%以提高边部温度;定期进行辊缝仪测试,加强检修力度和及时更换不良辊列,使其精度控制在合理范围内等,这些措施有效地改善了铸坯角部裂纹,使其降级比率和质量异议均低于当月该厂生产的Q235B钢。Based on the production practice of boron micro-alloyed medium-carbon steel A36- LB, the influence of molten steel compositions, boron content in steel, oscillating curve, cool- ing water flow in mould, secondary cooling scheme and and rolling gap precision on the trans- versal corner cracks in slab are analyzed, and the corresponding control measures are put for- ward such as making zv（S） less than 0. 015%, making the zv（Mn）/w（S） not less than 37. 6, strictly controlling the w（Ca）/w（Als） more than 0. 09 in molten steel, decreasing stroke by 1 mm and improving frequency to reduce negative sliding time by 32 %, maintaining the cooling water volume on the level of 4 000 and 380 L/min at the wide and narrow face of the mould, a- dopting the soft cooling curve to reduce the total volume of the secondary cooling water and at the same time cutting down the water volume at the edge portion of the slab by 50 ~ to raise the temperature of the slab edge, measuring the roll gap with the roll gap meter regularly so as to check, repair and exchange the worn out roll group timely and maintain the precision of the roll gap with in an appropriate range. As the results the comer cracks of the slabs are effective- ly improved and thus both the degradation rate and quality dispute rate are lower than that of the steel grade Q235 refined in the Plant.

关 键 词：硼微合金化 中碳钢 角部横裂 质量 

分 类 号：TF777[冶金工程—钢铁冶金]