预防精密冲压模具经年变寸的方法

Method of Prevent the for Years for a Change of Precision Punching Die

提出了预防精密模具及零件的"经年变寸"的方法及最佳热处理工艺。具体工艺方法和工艺参数是:模板线切割后先做一次650℃去应力退火;然后在真空炉中经过650℃和850℃预热,1 010℃加热,高压气淬;随后立即在-196℃深冷一次;接着250℃回火两次,最后200℃回火一次。生产实践证明,经过上述工艺处理的模板,残余奥氏体降至3%,变形量仅为0.000 8 mm。结果表明,用新工艺处理后的模板尺寸稳定性大大提高了,使用寿命也明显延长了。

The method and best heat treatment process to prevent the ＂for years for a change＂ of precision punching dies are presented. The method and parameters of heat treatment of dies are as follows. Firstly, after electric spark cutting, stress relief annealing of dies is used, which are heated to 650℃ and cooling in air furnace. Secondly, the dies are heated to 650 ℃ and 850 ℃ for pre -heating, then to 1 010 T： for quenching and the dies are cooled by pressed Nitrogen in vacuum furnace. Thirdly, the dies are deeply cooled to - 196 ℃, then, the tempering of dies is used which are heated to 250 ℃ for two times and following closely to 200 ℃ for one time. The production practice proved that after being treated by the above processes, the residual austenite of dies is decreased to 3%, the value of deformation is only 0. 000 8 mm. The result shows that, the dimension stability of dies is greatly increased and the life of dies is obviously prolonged.