What are the principles for the selection of stamping die materials
stamping parts are common processed parts in daily life. They are widely used due to their excellent processing properties. The processing principle of stamping parts is to use stamping equipment and stamping dies to process materials, so stamping dies are generally specialized. Sometimes, a complex part requires several sets of molds to be processed and formed, and the molds are manufactured with high precision and high technical requirements. It is a technology-intensive product. In addition, if the quality of the stamping die is not good, problems are likely to occur during the processing, so the selection of stamping die materials also has certain requirements.
First, the selection principle of stamping die material
1. Production batch, when mass production of stamping parts, the die punch and die material should be selected from high-quality, wear-resistant die steel. Other process structural components and mold auxiliary structural components also need improvement. When the batch is small, the performance requirements of the material can reduce the cost.
2. The performance of the material to be stamped. The conditions of use of the die. When the material to be stamped is hard or the deformation resistance is large, the convex and concave die of the die should be made of materials with good wear resistance and high strength. The aluminum bronze die has better adhesion resistance, so brushed stainless steel can be used. However, the guide column sleeve requires wear resistance and good toughness, so mild steel is mostly carburized and hardened. The main disadvantage of carbon tool steel is poor hardenability. When the section size of the stamping part is large, the center hardness after quenching is still low. . For fixing plate and stripping plate, it not only has sufficient strength, but also requires less deformation during the working process. In addition, the performance of parts can also be improved by cold and cryogenic treatment, by vacuum treatment and surface strengthening. For the cold extrusion die with harsh working environment of the convex and concave die, a die steel with sufficient hardness, strength, toughness, wear resistance and other comprehensive mechanical properties is selected, and it also has a certain red hardness and thermal fatigue strength.
3. Material properties, considering the cold and heat treatment properties of the material and the status of the factory.
In addition, it is common for blanking dies to burst during use, but in severe cases it is common for a die to be divided into several parts at a time. Of course, there are many reasons for the direct cracking of the template, and the procurement of materials from the mold design to the stamping process can all have an effect.
2. The main reasons for die bursting are as follows:
1. Unsmooth blanking.
In production, there is no demagnetization treatment and no demagnetization phenomenon; in production, there are broken needles, springs and other materials; when assembling the mold, there is no leakage, rolling and blocking, which is a common phenomenon. If you do not pay attention during the assembly process, if there are too many blanking holes or mold jams, air leakage, rolling blockage and foot blockage are prone to occur during the assembly process. This is a common phenomenon. It can easily happen if you are not careful during assembly, if there are too many blanking holes or if the mold has spacers.
2. Design process.
The strength of the die is not enough, the distance between the knife edges is too close, the structure of the die is unreasonable, the number of templates is insufficient, and there is no pad foot.
3. Heat treatment: improper quenching and tempering process leads to deformation.
The experimental results show that the heat treatment quality of the mold has a great influence on the performance and service life of the mold. Through the analysis and statistics of the causes of mold failure, it can be seen that mold failure accidents caused by improper heat treatment account for about 40%.