表面换热系数对铝厚板淬火温度和应力演变影响的数值模拟

淬火过程中表面换热系数是反映界面能量传递和介质冷却能力的重要物理参数.通过对铝厚板淬火的多组模拟实验,研究了表面换热系数对工件冷却速度、内应力演变的影响规律.结果表明,过大的表面换热系数并不能明显提高工件心部的冷却速度,却大大增加了工件的残余应力.铝厚板淬火工艺应根据工件的组织性能要求,合理选择表面换热系数和冷却方式,尽量减小工件的残余应力.

Numerical Simulating the Effect of Surface Heat Transfer Coefficient on Evolvement of Temperature and Stress of Thick Aluminum Alloy Plate

Surface heat transfer coefficient is an important physical parameter which reflects energy transfer of interface and cooling capability of medium. Based on several groups of simulated experiment with quenching thick aluminum alloy plate,the effect of the surface heat transfer coefficient on the cooling velocity and residual stress of the work piece has been studied. The result indicates that excessive heat transfer coefficient can't markedly improve the cooling rate in the centre of work piece,but greatly increase the residual stress of it. When quenching thick aluminum alloy plate,the surface heat transfer coefficient and cooling mode should be appropriately chosen so that the residual stress of it can be farthest minimized.