Abstract: The mathematical model for heat transfer of pipe line steel X80 (/% : 0. 04C, 1. 85Mn, 0. 25Si, 0. 006P, 0. 003S, 0. 30Ni, 0. 21Mo, 0. 06Nb, 0. 02V) 238 mm x 1 650 mm slab at vertical direction of strand has been established by two-dimensional cutting slice tracing slab solidification heat transfer method, and the calculation for change of shell thickness and temperature field of pipe line steel X80 slab during casting is carried out by ANSYS soft ware. It is obtained that with casting speed 1. 2 m/min the shell thickness of slab at out of mold is 18. 14 mm and the slab liquid core length is 22. 58 m. The relative error of solidification shell thickness between calculated data and measured data is ≤ 2. 5% , and that of terminal position of solidification is 0. 68%. The effect of superheating extent (25 - 55 °C ) , casting speed ( 1. 2 -1. 3 m/min) and secondary cooling water rate (79. 2 -96. 8 m³/h) on temperature at each point of cutting slice and terminal position of solidification is analyzed. The results show that with increasing casting speed and reducing secondary cooling water rate the slab surface temperature drops slowly, the terminal position of solidification distance from mold is farther and the solidification time is longer. The optimum process parameters for casting slab of pipe line steel X80 are superheating extent 35 ℃,casting speed 1. 2 m/min and secondary cooling water rate 88 m³/h.

摘要： 用二维切片跟踪铸坯凝固传热的方法建立了X80管线钢（/%:0.04C,1.85Mn,0.25Si,0.006P,0.003S,0.30Ni,0.21Mo,0.06Nb,0.02V）238 mm×1650 mm板坯连铸过程中垂直拉坯方向传热的数学模型,通过ANSYS对X80管线钢连铸过程中温度场及坯壳厚度的渐变进行计算,得出拉速1.2mm/min时,出结晶器坯壳厚为18.14 mm,铸坯液芯长22.58 m。凝固壳厚度计算值射钉测试结果的相对误差≤2.5%,凝固末端位置的相对误差为0.68%。分析了过热度（25~55℃）,拉速（1.2~1.3m/min）和二冷水量（79.2~96.8 m³/h）对切片各点温度和凝固末端位置的影响。结果表明,增大拉速、减小二冷配水量,连铸坯表面温降变慢,凝固末端位置距离结晶器液面越远,凝固时间变长;该X80管线钢板坯连铸最佳工艺参数为钢水过热度35℃,拉速1.2 m/min和二冷配水量88m³/h。

关键词: X80管线钢, 238 mm X 1 650 mm板坯, 连铸, 温度场, 坯壳厚度, 凝固末端