1. Wear resistance

Hardness is the primary factor affecting wear resistance. In general, the higher the hardness of mold parts, the smaller the wear amount, and the better the wear resistance. In addition, wear resistance is also related to the type, quantity, shape, size, and distribution of carbides.

The working conditions of molds are mostly very harsh, and some often accept large impact loads, which can lead to brittle cracking. To avoid sudden brittle fracture of mold parts during operation, the mold should have high strength and durability. The durability of a mold primarily depends on the carbon content, grain size, and arrangement state of the data.

During the process of mold operation, the long-term effect of cyclic stress often leads to fatigue and cracking. The methods include repeated small energy impact fatigue cracking, stretching fatigue cracking, touch fatigue cracking, and bending fatigue cracking. The fatigue cracking function of the mold mainly depends on its strength, resistance, hardness, and the content of impurities in the material.

When the operating temperature of the mold is high, it will cause a decrease in hardness and strength, leading to early wear or plastic deformation of the mold and failure. The mold data should have high resistance to tempering stability to ensure that the mold has high hardness and strength at operating temperatures.

Some molds are in a state of repeated heating and cooling during the operation process, causing tension and pressure on the surface of the mold cavity, resulting in surface cracking and peeling, increasing conflict force, preventing plastic deformation, reducing dimensional accuracy, and ultimately leading to mold failure. Cold and hot fatigue is one of the primary ways for hot work molds to fail, and such molds should have high resistance to cold and hot fatigue.

Some molds, such as plastic molds, contain elements such as chlorine and fluorine during operation. When heated, they decompose and release highly corrosive gases such as HCl and HF, which corrode the surface of the mold cavity, increase its surface roughness, and aggravate wear and failure.

The production of molds generally involves several processes such as casting, cutting, and heat treatment. To ensure the quality of mold production and reduce production costs, its materials should have outstanding malleability, machinability, hardenability, hardenability, and grindability; It should also have low sensitivity to oxidation and decarburization, as well as a tendency towards quenching deformation and cracking.

Has low resistance to hot forging deformation, good plasticity, wide casting temperature range, low tendency for forging cracking, cold cracking, and precipitation of network carbides.

The spheroidization annealing temperature range is wide, the annealing hardness is low and the shaking scale is small, and the spheroidization rate is high.

The cutting amount is large, the tool wear is low, and the surface roughness of the machined surface is low.

When heated at high temperatures, it has good antioxidant capacity, slow decarburization rate, insensitivity to the heating medium, and a small tendency to produce pitting.

After quenching, it has a uniform and high surface hardness.

After quenching, a deeper hardened layer can be obtained, and using a mild quenching medium can harden it.

Conventional quenching results in minimal volume changes, slight shape warping and distortion, and a low tendency for abnormal deformation. Conventional quenching has low sensitivity to cracking and is insensitive to quenching temperature and workpiece shape.

The relative wear of the grinding wheel is small, the burn free limit grinding amount is large, it is not sensitive to the quality and cooling conditions of the grinding wheel, and it is not easy to produce grinding damage and cracks.

When selecting materials for molds, it is necessary to consider the principle of economy and minimize production costs as much as possible. Therefore, on the premise of satisfying the usage function, the first priority is to choose lower priced ones. If carbon steel can be used, alloy steel is not necessary, and if domestic materials can be used, imported materials are not necessary.