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一、模具失效方式及影响使用寿命的因素冷冲模具在工作中主要失效方式有以下几种: 1.磨损: 模具在使用过程中,因磨损引起尺寸变化而失效,属于正常的失效方式。如落料冲孔时,模具因磨损而使刃口变钝,冲出的零件毛刺增大,最后停止工作;冷挤和冷镦时,被变形金属在模具表面强烈地流动而引起磨损,当磨损使模具的工作尺寸超过公差要求或因表面变得粗糙(拉毛)而使被加工零件的表面质量不能符合要求时,模具即失效。2.过量的塑性变形: 当模具承受的负荷超过钢材的屈服极限(或弹性极限)时,模具会产生过量的塑性变形,失去其尺寸的准确性而失效。例如冷挤压冲头所受负荷有时会超
First, the mold failure mode and the factors that affect the service life Die at work in the main failure modes are the following: 1. Wear: Mold in the course of use, due to wear caused by dimensional changes and failure, is a normal failure mode. Such as blanking punching, the mold due to wear and tear make the blade blunt, out of the parts burr increases, and finally stop working; cold extrusion and cold heading, the metal deformation caused by the strong flow on the mold surface caused by wear and tear, Mold wear out of the mold size exceeds the tolerance requirements or because the surface becomes rough (nap) so that the surface quality of the workpiece can not meet the requirements, the mold that failure. Excessive plastic deformation: When the mold to withstand the load exceeds the yield limit of steel (or elastic limit), the mold will have excessive plastic deformation, loss of accuracy of its size and failure. For example, cold extrusion punch load sometimes super