Enterprise centralized procurement of Cr12 machine-rolled stamping die steel CR12 chromium steel cold work die steel

Mold steel classification
The United States divides mold steel into three major categories according to mold service conditions. The American Metal Society Tool Steel Committee lists the three major categories of cold work mold steel, hot work mold steel and plastic mold steel. . Among them, cold work mold steel is divided into subcategories, hot work die steel subcategory and plastic mold steel subcategory. The selection of materials for each subcategory depends on three main factors
◆ Size and shape complexity,
◆ The material being processed,
◆ Durability requirements or design life.
Making mold steel
Divided into five groups: group, group, group, group, group.
◆ The group is water-quenched tool steel. There are two types of steel, one is carbon tool steel, and the carbon content ranges from.
◆ The group is oil-quenched cold-worked die steel (commonly known as oil steel). There is a steel type, containing carbon.
◆ The group is air-quenched alloy cold-worked die steel. There is a steel type, containing carbon. The amount is from.
◆ The group is high carbon and high chromium cold work die steel, there is a steel type, the carbon content.
◆ The group is impact resistant tool steel, there is a steel type, the carbon content.< br/> For cold work molds, there are also high-speed steel (group) and ultra-high-speed steel (group cobalt-based cemented carbide and steel-bonded cemented carbide (group powder steel) and engineering ceramics (group carbon tungsten tool steel (group special-purpose tools) Steel (group).
Selection of cold work die steel
The main series of cold work die steel is the high-hard cold work type, which is mainly used for molds that require high pressure resistance and wear resistance. It has high hardness For molds that require impact resistance and high toughness, the hardness is lower than that. Mainly use some types and the most common quenched and tempered steel, spring steel, hot work mold or base steel. For large stamping dies, such as automobile exterior Stamping parts are mainly made of cast iron. Simple ones or those with a small life span are made of zinc-based alloys or polymer composite materials.
The application of high-speed steel and ultra-high-speed steel in cold work dies is growing rapidly. Mainly due to their high resistance to Compressive strength/hardness ratio. And the hardness can be selected between.
Powder mold steel has excellent wear resistance life, the hardness is not high, and has many applications.
Carbon tool steel has a life span of 10,000 pieces Punch or soft material stamping dies still have a certain scope of application.
Die steel
American hot work die steel is divided into two categories: hot work die steel, and super hot-strength alloy.
Hot Since the mold works under high temperature conditions, the material is required to have thermal strength and thermal wear resistance. In order to ensure the service life of the mold, the mold must be cooled. The alternating hot and cold mold will cause cracks, that is, thermal fatigue cracks, so the material is It is required to have crack resistance and thermal fatigue resistance.
Select materials according to the main series arranged by thermal strength
Low alloy quenched and tempered die steel, medium chromium hot work die steel (,,) tungsten hot work die steel .
Non-standard hot work die steels such as hot upsetting dies are age hardened. When the hot wear resistance cannot be met, you can choose.
When the mold is required to be hot worked When wear resistance is the main priority, you can choose powder steel. Steel-bonded cemented carbide and cobalt-based cemented carbide have high high-temperature wear resistance, but their thermal fatigue resistance (ie, hot and cold fatigue crack resistance) is very poor. ,
Material mold steel
The United States is the first country to list special steel for plastic molds in tool steel, mainly represented by the past, divided into five categories.
◆ Carburized plastic mold steel ,,,,,. This type of steel has very low carbon content. It is mainly produced by the early American extrusion molding method. It requires good cold plasticity and high extrusion performance. After molding, the surface is carburized and quenched to increase the surface hardness. Long service life. The ultra-low carbon core can minimize the deformation during quenching.
◆Quenched and tempered plastic molds. Currently, they are used in large quantities in plastic molds and have become the main body. Most of them are used in the pre-hardened state. .
◆ Medium carbon alloy tool steel is used for thermosetting plastic molds. Steel grades include, and, and, and also have applications. The characteristic of this type is that it is basically a secondary hardened gold steel with good thermal strength.
Contains high chromium and is highly corrosive to the atmosphere.
Excellent hardenability, suitable for large modules.
◆Stainless steel is used for plastic molds with high corrosion resistance requirements. The main steel grades are,,,.
◆Aging steel is aged to obtain high performance. There are two types, one is low carbon aging steel and the other is maraging steel. The latter is a carbon-free, high-purity, high-strength, high-toughness material used in the aerospace industry. Used in plastic molds that require high mechanical properties, dimensional accuracy, smoothness and corrosion resistance.
Selection of plastic mold steel
Thin-walled plastic boxes are used when the production batch is less than 10,000 pieces, and the pre-hardened state (~ is used when it is highly corrosive.
Ordinary ones with long life Plastic molds are made of or, after carburizing and quenching, they can be used when the hardness of the plastic parts is not too large. Used when the corrosiveness is strong.
For non-high temperature thermosetting molds, they can be used after carburizing and quenching. Corrosion High temperature thermosetting plastic molds are made of and or carburized steel. These have high chromium content and have good tempering resistance and high temperature oxidation resistance.