55SiCr弹簧钢连铸纵-横冷却控制研究  

Study on longitudinal-transverse cooling control of 55SiCr spring steel continuous casting

作　　者：刘天威 黄俊雄 廖光键 姜双海 王军[2] 王超[1] 刘青[1] LIU Tianwei;HUANG Junxiong;LIAO Guangjian;JIANG Shuanghai;WANG Jun;WANG Chao;LIU Qing(State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijing 100083,China;Steelmaking Plant,Hunan Valin Xiangtan Iron Xiangtan Iron and Steel Group Co.,Ltd.,Xiangtan 411100,Hunan,China)

机构地区：[1]北京科技大学绿色低碳钢铁冶金全国重点实验室,北京100083 [2]湖南华菱湘潭钢铁集团有限公司炼钢厂,湖南湘潭411100

出　　处：《连铸》2024年第4期59-66,共8页Continuous Casting

摘　　要：合理的连铸二冷工艺制度是改善弹簧钢铸坯质量的关键之一。以某钢厂生产55SiCr弹簧钢150 mm×150 mm小方坯为研究对象,采用现场测温与Procast模拟计算结合的方法,通过建立考虑横向水量分布的凝固传热数学模型,分析了二冷区各段水量对连铸坯纵-横冷却不均匀性的影响,并提出了二冷配水优化方案控制纵-横冷却不均匀性。结果表明,在现行二冷配水方案下,连铸坯纵向温度分布不合理,矫直点处铸坯角部温度为922℃,处于55SiCr钢的第三脆性温度区;并且,铸坯在二冷区的表面横向最大温差较大,其值为360℃,容易引发角部裂纹和表面裂纹。基于上述研究结果,提出了适宜该钢种的二冷配水新策略及方案,即保持足辊段水量不变,将二冷区比水量由0.80 L/kg降至0.58 L/kg,调节二冷区一段和二段水量配比为3∶2。优化二冷区配水后,二冷区一段和二段铸坯表面中心水量比例分别由7.47%和5.57%增至14.48%和13.02%,角部水量比例分别由3.46%和5.45%减少到0和2.13%,使得矫直点处铸坯的角部温度提高到997℃,避开了第三脆性温度区,铸坯表面横向最大温差降至209℃,有利于降低连铸坯角部裂纹缺陷的发生率。Reasonable secondary cooling process system of continuous casting is one of the keys to improve the quality of spring steel billets. This paper takes 150 mm×150 mm billet of 55SiCr spring steel as the research object, adopting the method of in-situ temperature measurement and Procast numerical simulation calculation, the influence of secondary cooling water amount on the longitudinal-transverse cooling non-uniformity of the continuous casting billet was analyzed by the heat transfer and solidification model considering the water flux distribution along transverse direction, and optimization scheme for secondary cooling water amount was proposed to control the longitudinal-transverse cooling non-uniformity.The research results show that the longitudinal temperature distribution is unreasonable under the current secondary cooling water configuration scheme, and the corner temperature at the straightening point of casting billet is 922 ℃, which is in the third brittle temperature region of 55SiCr steel. Moreover, the maximum difference of transverse temperature on casting billet surface in the secondary cooling zone is large, and its value is 360 ℃, which is tend to cause corner and surface cracks. Based on the above research results, this paper proposed a new configuration strategy and scheme of secondary cooling water amount for this steel grade, keeping the water amount in foot roll section unchanged, reducing the specific water ratio in the secondary cooling zone from 0.80 to 0.58 L/kg, and regulating the water amount of in the first and second sections of the secondary cooling zone to 3∶2. After the optimization of water amount in secondary cooling zone, the spray water proportion at the center of billet surface in the first and second sections of the second cooling zone are increased from 7.47% and 5.57% to 14.48% and 13.02%,the spray water proportion at the corner of billet are reduced from 3.46% and 5.45% to 0 and 2.13%.The corner temperature of billet at the straightening point is increased to 997 �

关 键 词：55SiCr钢 连铸 二次冷却 水量配置 凝固传热 数值模拟 

分 类 号：TF777[冶金工程—钢铁冶金]