Q460钢3 250 mm x 150 mm宽板坯凝固传热数值模拟研究和应用

以Q460钢(/%:0.17C,0.35Si,1.5Mn,0.020P,0.020S,0.020Nb,0.075V)3 250 mm×150 mm宽板坯为研究对象,采用ANSYS软件建立凝固传热模型,研究拉坯速度、比水量、过热度等工艺参数对铸坯凝固过程的影响。模拟结果表明:拉坯速度每增大0.10 m/min,矫直段铸坯表面温度升高36.5℃,出坯温度升高50℃,坯壳厚度减薄2.4 mm,液心长度增加1.2 m;每增加1℃的过热度,矫直点铸坯上表面中心温度增加1.73℃,延长液芯长度0.11 m;因此,拉坯速度是影响铸坯质量的关键。生产应用表明,3 250 mm×150 mm板坯拉速1.20～1.25 m/min,过热度15～20℃时板坯表面矫直温度大于950℃,降低了铸坯中心疏松和偏析,表面质量显著提高。

Research and Application on Numerical Simulation of Solidification Heat Transfer of Q460 Steel 3250 mm x 150 mm Wide Slab

Taking Q460 steel (/% ：0. 17C,0. 35Si, 1. 5Mn, 0. 020P, 0.020S,0. 020Nb, 0. 075V) 3 250 mm x 150 mm wide slab as the research object, the solidification heat transfer model is established by ANSYS software, and the effects of casting speed, specific water rate and superheat etc process parameters on the solidification process of slab are studied. The simulation results show that when the casting speed increases by 0. 10 m/min, the surface temperature of slab at the straightening section increases by 36. 5 ℃ , the slab temperature increases by 50℃，the shell thickness decreases by 2. 4 mm, and the liquid core length increases by 1. 2 m； with increase of superheat of 1 ℃, the center temperature of upper surface of slab at the straightening point increases by 1. 73 °C and the length of the liquid core is extended by 0. 11 m； therefore, the casting speed is the key to quality of slab. Production application shows that by 3 250 mm x 150 mm slab cast speed 1. 20 ~ 1. 25 m/min, with superheat 15 ?20 ℃,the temperature of slab surface at straightening section is more than 950 ℃,to decrease the rating of center porosity and segregation and obviously increase surface quality.