材料期刊网

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4 mm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.

The temperature in the zone close to the surface rises and falls over and over again during the laminar cooling process,resulting in the difference of structure and properties in the thickness direction.According to the plant data during CSP hot rolling process in JISCO,a one dimensional model was established to simulate the strip temperature field during the cooling process.A new concept of impacting penetration depth was put forward,and explored the possible influential factors.The calculated temperature was higher than the measurement,with 3 ℃ for 3 mm thickness strip and 8 ℃ for 4 rnm thickness strip,and the relative error was 0.44 ％ and 1.16 ％,respectively,which proved the rationality of the model and the assumption.The results showed that the impacting penetration depth affected by the heat conductivity coefficient,the convective heat transfer coefficient,the strip surface temperature and the distribution of the nozzles.The impacting penetration depth increased with the increase of convective heat transfer coefficient,but the dense nozzle distribution in the bottom surface played the leading roles,the convective heat transfer coefficient had almost no effects on the impacting penetration depth.