How do we control the surface of stamping parts? Come here and take a look
Pouring parts are a common quality defect in production and generally exist in major automotive production plants.
On the one hand, La Mao reduces the stability and production efficiency of the production process, and the section rate of parts will increase. On the other hand, it will cause more severe wear in the mold, reduce the life of the mold life and stamping parts, increase the number of mold repair and production shutdown time.
The essence of pulling hair is due to the partial adhesion (bite) on the surface of the workpiece and mold.
There are many ways to improve the problem of hair pulling. The basic principle is to change the rubbing side of the mold and the processing parts, so that the friction side is replaced by materials that are not easy to stick to.
After the mold enters the production location debugging phase,
There are generally the following ways to improve the problem of pulling hair:
1. Change the mold material and increase the hardness of the mold;
2. Processing the surface of the mold, such as hard chrome, PVD and TD, etc.;
3. For mold -type cavity coating nano -coating, such as RNT technology, etc.;
4. Add a layer of other substances between the mold and the processing parts to separate the processing parts from the mold (such as coating lubrication or special lubricant or add a layer of PVC and other materials);
5. Use self -lubricating coating steel plate.
In terms of mold materials, mold steel SKD11, CR12MOV, etc. are recognized by everyone’s recognized wear -resistant and anti -bite materials. After the heat treatment, the hardness can reach chromium hardness HRC58-63 degrees. Such materials can be used when the mold is small and the part shape is simple. However, after the heat treatment of the material, it is difficult to process after treatment. It is crispy, easy to crack, high cost, and limited size. After the heat treatment of such materials is large, the research and distribution work is huge after the heat treatment.
The shape of the automotive interior parts is more complicated and more and more uses high -strength steel plates. Such parts have higher requirements for the overall performance of the mold. They usually use the collision structure. Hard chromium, nitrogen seepage, PVD, etc.
It is the abbreviation of the carbide coverage of the thermal diffusion method. The technology was first successfully developed and applied for a patent by the Toyota Central Research Institute of Japan in the 1970s. It is also known as the Toyota Diffusion Process. my country is also called
Molten salt penetration metal
Essence Regardless of its name, the principle is to place the workpiece in the melting borax mixture, and to form a metal carbide coverage on the surface of the workpiece through high temperature diffusion.
The main characteristics of TD layer treatment are: high -level hardness, HV can reach about 3,000, with high abrasion resistance, tensile injuries, corrosion resistance and other properties. The service life of the TD layer is about 100,000 units.
However, the TD layer treatment has high requirements for mold materials, and it is a high -temperature treatment of the thermal stress, phase degradation, and changes in the comparison of the mold. Cracking at the weld will also occur, and the TD layer treatment has high requirements for the processing quality and shape of the mold.
In addition, the TD layer is difficult to process after processing, which cannot meet the needs of design changes and model adjustment and modification. For molds that have been processed by other surface processing, the original surface processing needs to be completely cleared, otherwise it will affect the quality of the TD layer surface. In addition, the TD layer treatment technology generally disposes 3-4 times and will reduce service life after 3-4 times.
PVD (PHYSICAL VAPOR DEPOSITION) is the physical gas phase deposition method. PVD coating is the surface coating made of physical gas deposition method.
It has a good tensile injury performance. The hardness of the plating can be as high as HV2000-3000, or even higher, so it has excellent wear resistance, and its treatment temperature is relatively low. The advantages, but the binding force of the coating with the substrate is poor. It is easy to make the coating fall off when the depth mold and the molding pressure of the shaped mold and the molding pressure is large, and it cannot play its tensile injury and wear -resistant effect.
The size of the outer plate molds is generally large. If a mosaic structure is used, there will be strain at the gap. Therefore, most of the overall structure is used. The materials are generally used for cast iron such as ball and ink cast iron. After the forming of the material, the hardness can reach the chromium hardness HRC50-55 degrees after quenching.
The surface treatment of the overall structure of the overall structure is mostly a hard chrome process, but its surface hardening effect is limited, and the surface hardness is about 1000HV. In addition, the hard chrome coating is a mechanical combination with the mold mother material. When it comes off, once the coating is lost, it is lost. After the surface hardening layer is worn, the hair will appear again, and the life of the surface hardening layer is generally about 50,000 to 100,000 units.
RNT is an emerging technology in recent years. Its working principle is to coat the RNT coating liquid on the mold cavity, which spreads the coating nanomolecules and acts on the surface of the mold surface through pressure. The working time of the mold increases and increases, the thickness of the coating is 0.1-1 μm, and the hardness of the coating is in HV1100-1600. Even when the mold is suffering from a large load, the surface coating layer will not fall off due to the deformation of the base material. Its thickness and hardness increased from the inside to the increasing number of molds and the number of coatings.
The coating RNT coating once can generally guarantee 100-500 pieces. However, the application of this technology for severe parts, parts of the production process, and ultra -high -strength plates are not mature, and the cost of use is high.
Pull the hair before using RNT
Pull the hair after using RNT
The use of reasonable lubricants in the production process can effectively improve the friction conditions and reduce hair. Its main function is to use lubricating oil membrane to separate contact with the contact. Oil is generally used by manual oil or online head.
In addition, the use of lubricants can also effectively reduce the problem of dark injuries and cracking. However, the use of lubricants will make the environment dirty and smooth. In order to improve the impact of oil coating on the operating environment, in recent years, steel companies such as Baosteel, Wugang, and Malaysia have developed self -lubricating steel plates. The performance of corrosion resistance, fingerprint resistance, processing molding, and coating properties. It is mainly an organic coating on the roller on the steel plate. It does not need to apply lubricating oil during stamping. However, the cost of use is slightly higher and has not been widely used.
Because the molding load and the forming materials are very different, what or several measures are used to solve the problem of stusuality of the workpiece. In addition to considering the effectiveness of the effect, the batch size of the product must also be considered. In other aspects, choose the most suitable way.
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In order to answer your doubts, the above is what we have organized about stamping parts, hope it can help you.