Stamping die is an important process equipment in stamping production, and it is an effective means to improve product quality, save raw materials and reflect the technical economy of molded products. Durability of the die After the punch and die have been lost for a period of time due to frequent wear and tear, and can no longer meet the technical requirements of the part, the die is determined according to the total number of parts punched by the die. A pair of dies from design, machining, assembly, adjustment to installation and use, many processes, long cycle, high processing costs, therefore, in addition to the high efficiency of the die, the punched parts fully meet the quality requirements and technical conditions, the die The durability itself is also very important.

The durability of the die is closely related to the work failure phenomenon of the die. The failure phenomenon of the die work is the loss of the original design due to the change of the shape and size of the die and the material texture of the die component during use. A die can be considered to have failed if it has serious defects in the structure and cannot be used or is working but cannot perform the specified function. The later the failure occurs, the higher the durability of the die.

The durability of the die is very important in production. The higher the durability of the die, the longer the die life and the lower the cost of the part.

First, the failure form of the die

In actual production, the failure phenomenon of the die is quite frequent, and the die consumption is large. Therefore, the reasons for the failure of the die are analyzed, and various effective measures are taken to prevent the early failure of the die and improve the durability of the die.

1, wear and tear failure

The working part of the die should have a high wear resistance. Wear failure is the wear and tear of the die during use, and the relative motion between the parts or between the die and the workpiece is worn or even damaged by friction, vibration or high temperature fatigue cracking. In the initial part, the rough surface of the part is quickly removed, so the wear speed is very fast; in the normal wear stage, the wear of the part tends to be gentle, when the die is in the best technical state, the production efficiency shows the best level, the product The quality is the most guaranteed; after the normal wear period, the parts wear exceeds a certain limit, the normal wear relationship is destroyed, the contact condition is deteriorated, the wear speed is accelerated, and the die work performance is also rapidly degraded. If the wear parts are not repaired or replaced in time, the die will cause an accident. Loss of function, so that it is scrapped.

2, deformation failure

Deformation failure includes excessive elastic deformation or plastic deformation, high temperature creep, and the like. During the use of the die, due to the influence of various loads and alternating temperatures, as well as the performance changes of the material itself, the rigidity and toughness are insufficient, resulting in the die not working properly and failing.

3, brittle fracture failure

The die works under relatively harsh conditions, and is subjected to various loads, causing sudden breakage due to cracks and flaking, and failure due to fatigue failure and stress corrosion cracking, so the die often requires high toughness. Some dies are repeatedly heated and cooled during the working process, causing the surface to be subjected to tensile and compressive stresses, causing surface embrittlement and spalling, increasing frictional resistance and hindering plastic deformation of the workpiece, so that the die fails. This brittle fracture due to thermal fatigue is one of the main forms of die failure.

Second, the reasons that affect the durability of the die

1. Unreasonable influence of structural design

Die structure is the key to the durability of the die. Unreasonable structure is easy to cause poor rigidity and uneven wall thickness distribution. Surface defects (such as surface oxidation, decarburization, cracks, scars) will affect the performance of the material and cause early failure of the die. .

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