Cooling methods in the secondary cooling zone of high quality wheel steel

The effects of mist cooling and water cooling in the secondary cooling zone on the surface temperature, solidification strLlcture and macro-segregation of wheel steel casting billets were studied to explore the high-quality low-cost production technology of wheel steel. The results show that the surface temperature of the casting billets in the straightening segment is above 950℃ by both the cooling methods, which belongs to a high temperature plasticity zone and can avoid straightening cracks. A symmetrical solidification structure is obtained by both the cooling methods. Although mist cooling can slightly increase the proportion of equiaxed grains and decrease the central segregation of the casting billets, the dendrite arm spacing and the segregation degree around the half-radius region increase, which are even more unfavorable to the subsequent process and the quality of the finished product. Considering experimental results and production costs, water cooling should be more suitable for the production of high quality wheel steel.