中厚板辊式淬火机淬火过程的温度场分析

Temperature Field of Steel Plate on Roller Quenching Machine

通过建立中厚板辊式淬火机淬火过程的热传导控制方程,分析了热交换系数、淬火方式对中厚钢板淬火过程中温度场的影响.分析表明,淬火过程中,一定厚度的钢板,换热系数在一定范围内增大时,对流换热边界条件对钢板表面及内部温度变化影响效果显著;中厚板辊式淬火机淬火过程的特点在于,钢板首先通过冷却强度很大的高压淬火区冷却,使板材内部保持很大的温度梯度,从而保证板材获得较大的冷却速度;在较低冷却强度的低压淬火区完成淬火过程,板材内部温度梯度减小,可降低板材内部热应力.

The effects of heat transfer coefficient and quenching modes on the temperature field of a steel plate during quenching on a roller quenching machine were analyzed by a heat transfer control equation derived.The results showed that if the heat transfer coefficient increases within a certain range,the boundary conditions of convective heat transfer affect the surface and internal temperature of a plate of certain thickness significantly in its quenching process.It was found that the roller quenching machine has such characteristics that the steel plate is cooled in a high-pressure quenching zone where the cooling intensity is so high that the temperature gradient can be kept great inside the plate to ensure its high cooling rate,then the plate is fully quenched in the low-pressure quenching zone with lower cooling rate,thus decreasing the temperature gradient in the plate with its internal thermal stress reduced.