Mold, new material and heat treatment

With the improvement of product quality, the quality and longevity of the die are getting higher and higher. And the most effective way to improve the quality and life of the stamping die is to develop and apply new mould, new materials and new processing methods of heat and watch, and continuously improve the use performance of the material, and improve the processing performance of the stainless steel sheet stamping die material.

1.Stamping die material

The materials for manufacturing stamping die are steel, carbide, steel bonded carbide, zinc based alloy, low melting point alloy, aluminum bronze, hign polymer material, etc.. At present most of the stamping die manufacturing materials, etc.. At present most of the stamping die manufacturing materials made of steel, type of die components materials commonly used are: low carbon tool steel, alloy tool steel, high carbon high chromium or chromium tool steel, carbon steel, high-speed steel, cemented carbide and matrix steel, hard alloy steel etc..

A. Carbon tool steel
The carbon tool steel used in the mould is T8A, T10A and so on. The advantages are good processing performance and low price. But the hardenability and red hardness are poor, the deformation of heat treatment is large, and the load-carrying capacity is low.

B. Low-alloy tool steel
Low alloy tool steel is based on carbon tool steel with the proper amount of alloying elements. Compared with the carbon tool steel, the quenching deformation and cracking tendency are reduced, and the hardenability of the steel is improved, and the abrasion resistance is better. The low-alloy steels used for the manufacture of dies include CrWMn, 9Mn2V, 7CrSiMnMoV (code CH-1), 6CrNiSiMnMoV (code GP), etc..

C. High carbon high chromium tool steel
There are Cr12 and Cr12MoV, Cr12Mo1V1 high carbon high chromium tool steel commonly used (D2), which has good hardenability and abrasion resistance, heat treatment deformation is small, high wear-resistant micro deformation of die steel, bearing capacity after high speed steel. But the carbide segregation is serious, so it is necessary to make repeated upsetting (axial upsetting, radial drawing) to reduce the inhomogeneity of carbide and improve its performance.

D. High carbon medium chromium tool steel.
Cr4W2MoV, Cr6MV, Cr5MoV and other high carbon chromium tool steel used in the mold, the chromium content of their low eutectic carbides, carbides distribution, heat treatment, small deformation, good hardenability and dimensional stability. Compared with the high carbon high chromium steel and carbide segregation is relatively serious, the performance improved.

E. High speed steel

High speed steel has the highest hardness, wear resistance and compressive strength of die steel, and its carrying capacity is very high. Molds are commonly used in W18Cr4V (8-4-1) and less tungsten W6Mo5 Cr4V2 (6-5-4-2, American brand M2) and to improve the toughness of carbon reduction developed reduced vanadium high speed steel 6W6Mo5 Cr4V (6W6 or low carbon M2). High speed steel also needs to be modified to improve its carbide distribution.

F. Matrix steel

A small amount of other elements are added to the basic componet of the high speed steel to increase ot decrease the carbon content to improve the performance of the steel. Such steels are collectively referred to as matrix steels. They not only have the characteristics of high-speed steel, have a certain degree of wear resistance and hardness, and fatigue resistance and toughness are better than high-speed steel, high strength and toughness cold working die steel, but the cost of material is lower than high-speed steel. The matrix steel commonly used in mould is 6Cr4W3Mo2VNb (code 65Nb), 7Cr7Mo2V2Si (code LD), 5Cr4Mo3SiMnVAL (code 012AL) and so on.

G. Hard alloy and steel bonded carbide.
The hardness and wear resistance of cemented carbides are higher than those of other kinds of die steels, but their flexural strength and toughness are poor. Cemented carbide used as a mold is tungsten cobalt. For the die with small impact and high wear resistance, tungsten carbide with lower cobalt content can be chosen. For impact moulds, tungsten carbide with higher cobalt content can be selected.

Steel bonded carbide is made of iron powder with a small amount of alloy element powder (such as chromium, molybdenum, tungsten, vanadium, etc.) ad binder, and titanium carbide or tungsten carbide as hard phase, sintered by powder metallurgy method. The matrix of steel bonded carbide is steel, which overcomes the disadvantages of poor toughness and difficult processing of cemented carbide. It can be machined by cutting, welding, forging and heat treatment. Steel honde carbide contains a lot of carbide, although the hardness and wear resistance is lower than that of hard alloy, but it is still higher than other steel grades. After quenching and tempering, the hardness can reach 68-73HRC.

H. New material
The material uesed in stamping die is cold working die steel. It is a die steel with large amount of application, wide application and various kinds. The main performance requirements are strength, toughness and wear resistance. The current development trend of cold working die steel in high alloy steel D2 (equivalent to our performance on the basis of Cr12MoV), divided into two branches: one is reduce the amount of carbon and alloy elements, improve the distribution uniformity of carbides in steel, improve the toughness of the mold. Such as the United States vanadium alloy steel company 8CrMo2V2Si, Japan Datong special steel company’s DC53 (Cr8Mo2Siv) and so on. Another is to improve the wear resistance as the main purpose, to adapt to high-speed, automation, mass production and development of powder high-speed steel. Such as Germany’s 320CrVMo13, and so on.