What is the Purpose of Mold Steel? What are the materials of mold steel?

When processing molds, because the use of molds is very wide, the working conditions of various molds are very different, therefore, the range of materials used in manufacturing molds is very wide, and the most widely used in mold materials is mold steel. From general carbon structural steel, carbon tool steel, alloy structural steel, alloy tool steel, spring steel, high-speed tool steel, stainless heat-resistant steel to meet the needs of special molds martensitic aging steel, powder high-speed steel, powder high-alloy die steel, etc. Die steel can generally be divided into three categories: cold work die steel, hot work die steel and plastic die steel according to its use.

Cold Work Die Steel Cold work die steel is mainly used to manufacture molds for pressing and forming workpieces in a cold state. Such as: cold stamping die, cold stamping die, cold drawing die, embossing die, cold extrusion die, thread pressing die and powder pressing die, etc.

There is a wide range of cold work die steels, from various carbon tool steels, alloy tool steels, and high-speed tool steels to powdered high-speed tool steels and powdered high-alloy die steels. Hot Work Die Steel Hot work die steel is mainly used to manufacture molds for pressure processing of workpieces at high temperatures. Such as:

Hot forging dies, hot extrusion dies, die-casting dies, hot forging dies, etc. Commonly used hot work die steels are: alloy die steels with medium and high carbon content adding Cr, W, Mo, V and other alloying elements; For special requirements of hot work die steel, sometimes made of high-alloy austenitic heat-resistant die steel.

Plastic mold steel Because there are many varieties of plastics, the requirements for plastic products are also very different, and various different performance requirements are also put forward for the materials used to manufacture plastic molds. Therefore, many industrially developed countries have formed a wide range of steel series for plastic molds. Including carbon structural steel, carburizing plastic mold steel, pre-hardened plastic mold steel, age-hardening plastic mold steel, corrosion-resistant plastic mold steel, easy-cut plastic mold steel, integral hardened plastic mold steel, martensitic aging steel and plastic mold steel for mirror polishing.

Mould steel material:

1. Cold work die steel.

Cold work molds are the most widely used molds. The output value of cold work mold has always been the highest in the mold manufacturing industry, and in recent years, due to the rapid development of plastic molds, it has retreated to the second place in the output value of mold industry in many industrially developed countries. At present, the more common cold work die steel can be divided into three categories according to the strength:

1) Low-alloy cold-work die steel.

Mainly CRWMN and 9MN2V, the wear resistance and hot hardness are relatively poor, and in the case of cost saving, oil quenching can generally be used, which is widely used in the production of cold work molds with small batches.

2) Medium alloy cold work die steel.

Represented by CR5MO1V, it has medium wear resistance and hot hardness, high toughness, good hardenability, air quenching, good comprehensive performance, and is widely used in cold work molds for the production of medium-batch products.

3) High-carbon, high-chromium cold-work die steel.

Represented by CR12MO1V1 and CR12 steel, the wear resistance and hot hardness are high, and the reason why the toughness is poor is because it contains a large amount of eutectic carbide, which is widely used in the production of cold work molds with large batch sizes and high wear resistance but small impact load.

2. Hot work die steel.

Hot work die steel is mainly used to manufacture die steel for hot processing of metal materials.

1) Low-alloy hot work die steel.

Representative steel grades are 5CrMnMo and 5CrNimo. This kind of steel has good hardenability and impact toughness, but the hot hardness is not enough, "generally used for molds with low working temperature and large impact loads, such as hammer forging dies."

2) Medium alloy hot work die steel.

This kind of steel is chromium-based hot work die steel, and the representative steel grades are 4Cr5MOSIV1 (H13) and so on. This kind of steel has good comprehensive mechanical properties, high hot hardness, cold and hot fatigue resistance and liquid metal erosion resistance, and has been widely used in forging dies, aluminum alloy die-casting dies and hot extrusion dies, becoming the most widely used type of hot work die steel.

3) High-alloy hot work die steel.

The most widely used is the traditional tungsten hot work die steel, such as 3Cr2W8V, etc. Most of the molds used for higher working temperatures have been replaced by medium alloy hot work die steels in recent years. In order to meet the special requirements of some hot work molds, some new high-performance hot work die steels have been developed, mainly 4Cr3Mo3WVNL (GR Mn9Ni4Cr8V2WMO, 4Cr3Mo2NivNLB (HD Cr3Mo2NiVsi (PH) steel, etc.

Die steel refers to steel that contains a variety of metal elements. Mold steel (die steel) is used to produce various types of molds such as: plastic molds, plastic molds, drawing molds, stamping molds, die-casting molds, extrusion molds, hot forging molds and so on.

The quality of the mold directly affects the quality of the pressure processing process, the accuracy output of the product and the production cost, and the quality and service life of the mold are mainly affected by the mold material and heat treatment in addition to the reasonable structural design and processing accuracy.

Die Steel Classification:

1. Cold work die steel.

It is mainly used to manufacture molds that are pressed and formed under cold state (room temperature) conditions. Such as cold stamping die, cold drawing die, cold pier die, cold extrusion die, embossing die, rolling die, etc.

The commonly used steels for cold work die steel are: CR12 die steel, CR12MOV die steel, SKD11 die steel, D2 die steel, DC53 die steel, 2379 die steel, 2510 die steel, DF2 die steel, SKH-9 high speed steel, M2 high speed steel, ASP23 powder high speed steel, ASP60 powder high speed steel.

2. Hot work die steel.

It is mainly used to make molds for hot forming of metals at high temperatures. Such as hot forging molds, hot extrusion molds, die-casting molds, hot shear molds, etc.

The commonly used steels for hot work die steel are: sulfur-free 8407 die steel, 8418 die steel, 2344 die steel, SKD61 die steel, DAC die steel, FDAC die steel, and high molybdenum H13 die steel.

3. Plastic mold steel.

Also known as plastic mold steel, it is mainly used for plastic forming molds. Plastic molds are in the first place in mold making. There are many classifications of plastic mold steel, mainly including:

Pre-hardened plastic mold steel, age-hardening mold steel, corrosion-resistant mold steel, free-cutting mold steel, martensitic aging plastic mold steel, mirror polished plastic mold steel.

The commonly used steels for plastic mold steel are: 2311 mold steel, P20 mold steel, 738H mold steel, 718H mold steel, NAK80 mold steel, 2083 mold steel, S136 mold steel, and breathable steel PM-35.

Carburizing plastic mold steel: 20Cr, 12CrNi3A.

Anti-wear cold work die steel: 6Cr4W3MovnB, 6W6Mo5Cr4V, 7Cr7Mo3V2Si, Cr4W2MoV, Cr5Mo1V, Cr6Wv, Cr12, Cr12MoV, Cr12W, Cr12Mo1V1.

Low heat resistance hot work die steels: 5CrMnMo, 5CrNimovsi, 4CrMnsimov, 5Cr2Nimovsi.

Quality improvement. 1. Use the metamorphic effect of trace elements such as CA and rare earth on the inclusions to change the structural morphology and physical properties of the inclusions in the steel, so that the inclusions in the steel are spheroidized and refined, so as to improve the mechanical properties of the steel.

2. High-temperature diffusion heat treatment of the steel ingot can improve the non-uniformity of the composition of the steel ingot, thereby improving the transverse properties of the steel.

3. In terms of thermal processing, repeated upsetting and multi-directional rolling of steel ingots can increase the amount of deformation, which can reduce the level of carbide segregation in steel, and is also conducive to improving the anisotropy of steel.

4. The purity of the steel has a great impact on the isotropic properties of the die steel, and the use of secondary refining technology (including vacuum refining, ESR and ladle powder spraying, etc.) can improve the purity of the steel, especially reduce the content of harmful impurities in the steel, which is very beneficial to improve the performance.

Die steel is a steel grade used to make cold stamping dies, hot forging dies, die-casting dies and other molds. Molds are the main processing tools for manufacturing parts in industrial sectors such as machinery manufacturing, radio instruments, motors, and electrical appliances. There is a wide range of materials used in the manufacture of molds, and the most widely used mold materials are mold steel.

Mold steel is a traditional mold material, and its variety, specification and quality play a decisive role in the performance, service life and manufacturing cycle of the mold. Die steels can be roughly divided into the following types:

1. According to the chemical composition, it is divided into:

1. Carbon steel: S50C, S55C

2. Alloy steel: low alloy steel (5%); medium alloy steel (5% 10%); High-alloy steel (10%).

2. According to the use of use, it is divided into:

Plastic mold steel, cold work mold steel, hot work mold steel.

Mold steel is a steel grade used to make molds such as cold stamping dies, hot forging dies, die casting molds, etc. Mold material is the material and technical basis of the mold manufacturing industry, in which the mold steel is the traditional mold material, and its variety, specification and quality play a decisive role in the performance, service life and manufacturing cycle of the mold.

Mold Steel Properties:

Die steel is a multi-purpose comprehensive cold work tool steel. It has good adhesion resistance, high wear resistance, high toughness and good chipping resistance. After high temperature tempering, a high hardness of 55-60HRC can be obtained.

2. Therefore, for cutting the mold with complex shape by wire cutting from a large section with high hardness (>HRC59), the risk of cracking can be reduced. In addition, high-strength substrates are particularly suitable for surface treatments such as nitriding or PVD.

3. Steel is a general term for iron-carbon alloys with a mass percentage of carbon content between to. The chemical composition of steel can vary greatly, and steel that contains only carbon elements is called carbon steel (carbon steel) or ordinary steel; In actual production, steel often contains different alloying elements according to different uses, such as: manganese, nickel, vanadium and so on.

4. The application and research history of steel by human beings is quite long, but until the invention of the Bayesian steelmaking method in the 19th century, the production of steel was a high-cost and low-efficiency rolling work.

5. Nowadays, steel has become one of the most widely used materials in the world with its cheap and reliable properties, and is an indispensable component of the construction industry, manufacturing industry and people's daily life. It can be said that steel is the material basis of modern society. <