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目前,重载模具的寿命问题最为突出。例如在曲柄热冲压机上冲挤阀的阴模寿命为800～1500件(阴模使用寿命约2小时)。用于锻造曲轴和连杆的昂贵锻模也发现有类似的情况。锻模寿命低的原因之一是模坯的制造工艺流程不完善,该工艺流程为塑性变形(通常对“纤维紊乱”的小锻件而言)—→变形后缓冷—→退火—→机械加工—→最终热处理(淬火和一次或多次回火)—→氮化。锻造时是否一定要产生“纤维紊乱”?如果不是,那么在这种情况下又如何修改热处理工艺规范?锻件自终锻温度淬火是否合理?如何退火——是第
At present, the life of heavy molds the most prominent problem. For example, in the hot stamping machine crank squeeze valve die life of 800 to 1500 pieces (die life of about 2 hours). A similar situation was found with expensive forging dies for crankshafts and connecting rods. One of the reasons for the low die life is that the die manufacturing process is imperfect, the process is plastic deformation (usually for the “fiber disorder” small forgings) - → slow cooling after deformation - → annealing - → machining - → final heat treatment (quenching and tempering one or more times) - → nitriding. Is it necessary to produce a “fiber disorder” during forging? If not, how to modify the heat treatment process specification in this case? Is it reasonable for the forging temperature to quench itself? How to anneal -