With the popularization of automated forging in China, more and more enterprises are adopting multi station automated forging equipment to form forgings. Because the load distribution of each process in the manufacturing process is reasonable, the mold can achieve the most ideal lifespan. Now let's talk about how to improve the lifespan of forging molds, hoping to be helpful to you!
Change the performance of cold forging molds
1. Change the mold material
Replace high-speed steel 6542, SKH51, SKH55, etc. with hard alloys; Hard alloy is a material with high strength and excellent wear resistance. It is an alloy material made by powder metallurgy process of hard compounds of refractory metals and bonding metals. Its basic composition is tungsten carbide, and the important factor determining the microstructure of superhard alloys depends on the carbon content. As a mold component, its service life is 20-150 times longer than that of alloy tool steel. Change hard alloy to non cobalt or low cobalt binder hard alloy. Research has shown that hard alloys with low cobalt content have higher bending strength and impact toughness.
2. Reduce the surface roughness of the mold
Grinding and polishing are necessary processes for manufacturing precision forging molds and are also key to the lifespan of the molds. The purpose of grinding is to remove the marks left by mechanical cutting, remove the surface damage layer left by electrical discharge machining, and lay a good foundation for polishing, usually achieving Ra=0.2 μ m or less. The purpose of polishing is to make the surface of the mold mirror like, extremely smooth, reduce friction, and greatly improve the lifespan of the mold. Usually, Ra should be below 0.04 to 0.02 μ m.
3. PVD coating
Different coatings such as TiN, TiCN, TiAlN, CrN, etc. should be selected for various materials. The coating requirements for precision cold forging molds are high adhesion and appropriate coating thickness. TiN has high melting point, high hardness, excellent thermal and chemical inertness, conductivity, and corrosion resistance. The higher the power of the coating, the more pronounced the prepared coating and the more obvious its performance; TiCN is a non oxide material with excellent performance, widely used as a coating material in surface engineering due to its good corrosion resistance and wear resistance, which can improve the service life of molds. Titanium nitride is a material that combines the advantages of titanium nitride and carbon nitride. Its hardness is higher than that of titanium nitride, and it is not as prone to detachment as titanium carbide; The room temperature hardness of nitrogen aluminum titanium coating is usually lower than that of carbon nitride titanium coating, but it is more effective than carbon nitride titanium coating at high temperatures. The reason why it can maintain hardness at high temperatures is that a layer of aluminum oxide can be formed on the surface of the mold; CrN coating has high hardness, ductility, adhesion, low friction coefficient, corrosion resistance, thermal stability, etc., and has been widely used as a wear-resistant coating for tools and molds.
