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带钢在层流冷却过程中距表面较近的区域温度存在反复升降的现象,造成厚度方向上组织和性能的差异。结合酒钢CSP热轧带钢生产数据,建立一维热轧带钢有限元模型,计算层流冷却过程中带钢的温度场。提出了冷却过程中带钢冲击穿透深度的概念,并初步探究其影响因素。厚度为3和4mm的带钢计算得出的卷取温度比实测温度分别高3和8℃,相对误差分别为0.44%和1.16%,验证了模型和假设的合理性。结果表明,冷却过程中冲击穿透深度受带钢的导热系数、平流区的对流换热系数、带钢表面温度和喷嘴分布的影响;带钢上表面喷嘴分布较少,冲击穿透深度随对流换热系数的增大而增加,下表面喷嘴分布密集起主导作用,增加对流换热系数,冲击穿透深度几乎不受影响。
Strip steel in the laminar cooling process in the area near the surface temperature there is the phenomenon of repeated movements, resulting in the thickness of the organization and performance differences. According to the production data of CSP hot-rolled strip, the one-dimensional finite element model of hot rolled strip was established and the temperature field of strip during cooling in laminar flow was calculated. The concept of impact penetration depth of strip during cooling is put forward and its influencing factors are preliminarily explored. The calculated coiling temperature of strip with thickness of 3 and 4mm were 3 and 8 ℃ higher than the measured temperature, respectively. The relative errors were 0.44% and 1.16% respectively, which validated the rationality of the model and the assumptions. The results show that the impact penetration depth during cooling is affected by the thermal conductivity of the strip, the convective heat transfer coefficient in the stratosphere, the surface temperature of the strip and the nozzle distribution. The distribution of nozzles on the upper surface of the strip is less and the impact penetration depth varies with convection The increase of heat transfer coefficient increases, and the distribution of nozzle on the lower surface is intensive, leading to increase of convection heat transfer coefficient and impact penetration depth hardly affected.