摘要
热轧产线在实际生产过程中,中间坯受到各道次的温度限制,需要空冷待温,对产线轧制效率产生一定影响。通过有限元模拟分析,投用中间冷却工艺后,中间坯经超密度集管进行快速冷却,结合20~50 s的空冷返温时间,中间坯内外温度趋于均匀,厚度方向最大温差小于28℃,可以有效提高板坯性能稳定性,降低摆钢空冷时间,提高轧制效率。设计研发出一种超密度布置的中压水喷射冷却集管装置,并将该中间冷却设备投入车轮钢的实际生产应用。结果表明:对比常规车轮钢实际生产情况,当投入中间冷却设备之后,每块板坯平均轧制时间由115 s缩短至102 s,轧制节奏缩短13 s,机时卷数提高4卷/h,每小时可提高产量104 t;对比不同中间冷却水投入组数和产品的组织及性能情况,当中间冷却设备投入的冷却水组数增加,车轮钢沿轧制方向的带状组织碎断程度逐步完全,芯部晶粒尺寸更为细小,且多为等轴晶;随中间冷却设备投入的冷却水组数增加,车轮钢屈服强度波动降低42 MPa,断后伸长率波动降低至2%,其性能越趋于稳定,同时也减小了车轮钢低温冲击功的波动。
In the actual production process of the hot rolling production line,the intermediate billet is limited by the temperature of each pass,and it needs air cooling to wait for temperature,which has a certain impact on the rolling efficiency of the production line.Through the finite element simulation analysis,after the intermediate cooling process is put into use,the intermediate billet is rapidly cooled by the ultra-density header.Combined with the air cooling rewarming time of 20—50 s,the temperature inside and outside the intermediate billet tends to be uniform,and the maximum temperature difference in the thickness direction is less than 28℃,which can effectively improve the property stability of the slab,reduce the air cooling time of pendulum steel and improve the rolling rhythm.A medium-pressure water jet cooling header device with ultra-density layout was designed and developed,and the intermediate cooling equipment was put into the actual production application of wheel steel.The results show that compared with the actual production of conventional wheel steel,when the intermediate cooling equipment is put into operation,the average rolling time of each slab is shortened from 115 s to 102 s,the rolling rhythm time is shortened by 13 s,the number of coils per hour is increased by 4 coils/h,and the output per hour can be increased by 104 t.By comparing the number of different intermediate cooling water groups input and the microstructure and properties of the products,when the number of cooling water groups input by the intermediate cooling equipment increases,the banded structure of the wheel steel along the rolling direction is gradually broken completely,and the grain size in the center is smaller,and most of them are uniform equiaxed crystal.With the increase of the number of cooling water groups input by the intermediate cooling equipment,the yield strength fluctuation of wheel steel decreases by 42 MPa,and the elongation fluctuation after fracture decreases to 2%,and its properties tends to be more stable.At the same time,it also reduces the fluctuation of impact energy of wheel steel at low temperature.
作者
李建伟
高文刚
刘靖群
梁江涛
李瑞
黄爽
LI Jianwei;GAO Wengang;LIU Jingqun;LIANG Jiangtao;LI Rui;HUANG Shuang(Shougang Jingtang Iron and Steel United Co.,Ltd.,Tangshan 063200,China;Research Institute of Technology,Shougang Group Co.,Ltd.,Beijing 100043,China)
出处
《轧钢》
北大核心
2024年第4期59-65,共7页
Steel Rolling
关键词
中间冷却
车轮钢
轧制节奏
显微组织
力学性能
高效率
intermediate cooling
wheel steel
rolling rhythm
microstructure
mechanical properties
high efficiency
