Different types of press tool material

a. Carbon tool steel（press tools)
The carbon tool steels widely used in molds are T8A and T10A, which have the advantages of good processability and low price. However, the hardenability and red hardness are poor, the heat treatment deformation is large, and the bearing capacity is low.

b. Low alloy tool steel(press tools)
Low alloy tool steel is based on carbon tool steel with an appropriate amount of alloy elements. Compared with carbon tool steel, the quenching deformation and cracking tendency are reduced, the hardenability and wear resistance of the steel are improved. Low alloy steels used for manufacturing molds include CrWMn, 9mn2v, 7CrSiMnMoV (code CH-1), 6crnisimnmov (code GD), etc.

c. High carbon and high chromium tool steel(press tools)
The commonly used high carbon and high chromium tool steels are Cr12 and Cr12MoV, Cr12Mo1V1 (code D2) and SKD11. They have good hardenability, hardenability and wear resistance. They have little heat treatment deformation. They are high wear-resistant micro deformation die steels, and their bearing capacity is second only to high-speed steel. However, the carbide segregation is serious, so repeated upsetting and drawing (axial upsetting and radial drawing) must be carried out to reduce the heterogeneity of carbide and improve the service performance.

d. High carbon medium chromium tool steel(press tools)
High carbon medium chromium tool steels used for molds include Cr4W2MoV, cr6wv, Cr5MoV, etc. they have low chromium content, few eutectic carbides, uniform carbide distribution, small heat treatment deformation, good hardenability and dimensional stability. Compared with high carbon and high chromium steel with relatively serious carbide segregation, the properties are improved.

e. High speed steel(press tools)
High speed steel has the highest hardness, wear resistance and compressive strength in die steel, and its bearing capacity is very high. W18Cr4V (code 8-4-1), W6Mo5 Cr4V2 (code 6-5-4-2, American brand m2) with less tungsten and 6w6mo5 cr4v (code 6w6 or low carbon m2), a carbon and vanadium reduction high-speed steel developed to improve toughness, are commonly used in molds. High speed steel also needs to be forged to improve its carbide distribution.

f. Base steel
In order to improve the properties of high speed steel, a small amount of other elements are added to the basic composition of high speed steel and the carbon content is appropriately increased or decreased. Such steel is collectively referred to as base steel. They not only have the characteristics of high-speed steel and have certain wear resistance and hardness, but also have better fatigue strength and toughness than high-speed steel. They are high-strength and toughness cold working die steel, but the material cost is lower than high-speed steel. The matrix steels commonly used in molds include 6cr4w3mo2vnb (code 65Nb), 7Cr7Mo2V2Si (code LD), 5cr4mo3simnval (code 012AL), etc.

g. Cemented carbide and steel bonded cemented carbide
The hardness and wear resistance of cemented carbide are higher than any other kind of die steel, but the bending strength and toughness are poor. Cemented carbides used as molds are tungsten cobalt. For molds with low impact and high wear resistance, cemented carbides with low cobalt content can be selected. For high impact dies, cemented carbide with high cobalt content can be selected.

Steel bonded cemented carbide is sintered by powder metallurgy with iron powder added with a small amount of alloy element powder (such as chromium, molybdenum, tungsten, vanadium, etc.) as binder and titanium carbide or tungsten carbide as hard phase. The matrix of steel bonded cemented carbide is steel, which overcomes the shortcomings of poor toughness and difficult processing of cemented carbide. It can be cut, welded, forged and heat treated. Steel bonded cemented carbide contains a lot of carbides. Although its hardness and wear resistance are lower than that of cemented carbide, it is still higher than other steel grades. After quenching and tempering, the hardness can reach 68 ~ 73 HRC.

h. New material
The material used in stamping die belongs to cold working die steel, which is a die steel with large application, wide application and the most kinds. The main performance requirements are strength, toughness and wear resistance. The development trend of cold work die steel is based on the properties of high alloy steel D2 (equivalent to Cr12MoV in China), which is divided into two branches: one is to reduce the carbon content and alloy element content, improve the uniformity of carbide distribution in the steel, and highlight the improvement of die toughness. For example, 8crmo2v2si of American vanadium alloy steel company and DC53 (cr8mo2siv) of Datong special steel company in Japan. The other is powder high-speed steel developed to improve wear resistance and adapt to high-speed, automatic and mass production. Such as 320crvmo13 in Germany, etc.