Tungsten steel (tungsten carbide) has a series of excellent properties such as high hardness, wear resistance, good strength and toughness, heat resistance and corrosion resistance, especially its high hardness and wear resistance, even at a temperature of 500 ℃. It remains basically unchanged, and still has a high hardness at 1000 °C.

Chinese name： tungsten steel

Foreign name ：Cemented Carbide Alias ​

Features ：High hardness, wear resistance, good strength and toughness

Products：Round rod, tungsten steel plate

Introduction:

Tungsten steel, also known as cemented carbide, refers to a sintered composite material containing at least one metal carbide. Tungsten carbide, cobalt carbide, niobium carbide, titanium carbide, and tantalum carbide are common components of tungsten steel. The grain size of the carbide component (or phase) is typically between 0.2-10 microns, and the carbide grains are held together using a metallic binder. The binder usually refers to the metal cobalt (Co), but for some special applications, nickel (Ni), iron (Fe), or other metals and alloys can also be used. A compositional combination of carbide and binder phase to be determined is referred to as a “grade”.

The classification of tungsten steel is carried out according to ISO standards. This classification is based on the material type of the workpiece (such as P, M, K, N, S, H grades). The binder phase composition is mainly used for its strength and corrosion resistance.

The matrix of tungsten steel consists of two parts: one part is the hardening phase; the other part is the bonding metal. Binder metals are generally iron group metals, commonly used cobalt and nickel. Therefore, there are tungsten-cobalt alloys, tungsten-nickel alloys and tungsten-titanium-cobalt alloys.

For steels containing tungsten, such as high-speed steel and some hot work die steels, the tungsten content in the steel can significantly improve the hardness and heat resistance of the steel, but the toughness will drop sharply.

The main application of tungsten resources is also cemented carbide, that is, tungsten steel. Carbide, known as the teeth of modern industry, is widely used in tungsten steel products.

Ingredient structure

Sintering process:

Sintering of tungsten steel is to press the powder into a billet, then enter the sintering furnace to heat to a certain temperature (sintering temperature), keep it for a certain time (holding time), and then cool it down, so as to obtain the tungsten steel material with the required properties.

Four basic stages of tungsten steel sintering process:

1. In the stage of removing the forming agent and pre-sintering, the sintered body undergoes the following changes at this stage:

Removal of the molding agent, with the increase of temperature in the initial stage of sintering, the molding agent gradually decomposes or vaporizes, and the sintered body is excluded. The type, quantity and sintering process are different.

The oxides on the surface of the powder are reduced. At the sintering temperature, hydrogen can reduce the oxides of cobalt and tungsten. If the forming agent is removed in vacuum and sintered, the carbon-oxygen reaction is not strong. The contact stress between the powder particles is gradually eliminated, the bonding metal powder begins to recover and recrystallize, the surface diffusion begins to occur, and the briquetting strength is improved.

2. Solid phase sintering stage (800℃——eutectic temperature)

At the temperature before the appearance of the liquid phase, in addition to continuing the process of the previous stage, the solid-phase reaction and diffusion are intensified, the plastic flow is enhanced, and the sintered body shrinks significantly.

3. Liquid phase sintering stage (eutectic temperature – sintering temperature)

When the liquid phase appears in the sintered body, the shrinkage is completed quickly, followed by crystallographic transformation to form the basic structure and structure of the alloy.

4. Cooling stage (sintering temperature – room temperature)

At this stage, the structure and phase composition of tungsten steel have some changes with different cooling conditions. This feature can be used to heat-trench tungsten steel to improve its physical and mechanical properties.

Application introduction

Tungsten steel belongs to cemented carbide, also known as tungsten-titanium alloy. The hardness can reach 89~95HRA. Because of this, tungsten steel products (common tungsten steel watches) are not easy to be worn, hard and not afraid of annealing, but brittle.

The main components of cemented carbide are tungsten carbide and cobalt, which account for 99% of all components, and 1% are other metals, so it is also called tungsten steel.

Commonly used in high-precision machining, high-precision tool materials, lathes, impact drill bits, glass cutter bits, tile cutters, hard and not afraid of annealing, but brittle. Belongs to the rare metal.

Tungsten steel (tungsten carbide) has a series of excellent properties such as high hardness, wear resistance, good strength and toughness, heat resistance and corrosion resistance, especially its high hardness and wear resistance, even at a temperature of 500 ℃. It remains basically unchanged, and still has a high hardness at 1000 °C. Carbide is widely used as a material, such as turning tools, milling cutters, planers, drills, boring tools, etc., for cutting cast iron, non-ferrous metals, plastics, chemical fibers, graphite, glass, stone and ordinary steel, and can also be used for cutting resistant steel. Difficult-to-machine materials such as hot steel, stainless steel, high manganese steel, tool steel, etc. The cutting speed of the new cemented carbide is hundreds of times that of carbon steel.

Tungsten steel (tungsten carbide) can also be used to make rock drilling tools, mining tools, drilling tools, measuring tools, wear-resistant parts, metal abrasives, cylinder linings, precision bearings, nozzles, etc.

Comparison of tungsten steel grades: S1, S2, S3, S4, S5, S25, M1, M2, H3, H2, H1, G1 G2 G5 G6 G7 D30 D40 K05 K10 K20 YG3X YG3 YG4C YG6 YG8 YG10 YG12 YL10.2 YL60 YG15 YG20 YG25 YG28YT5 YT14 YT15 P10 P20 M10 M20 M30 M40 V10 V20 V30 V40 Z01 Z10 Z20 Z30

Tungsten steel, cemented carbide knives, and various tungsten carbide standard specifications have a large inventory, and the blanks are available from stock.

Material series

Typical representative products of tungsten steel series materials are: round bar, tungsten steel sheet, tungsten steel strip, etc.

Mold material

Tungsten steel progressive dies, tungsten steel drawing dies, tungsten steel drawing dies, tungsten steel wire drawing dies, tungsten steel hot extrusion dies, tungsten steel cold stamping dies, tungsten steel forming blanking dies, tungsten steel cold heading dies, etc.

Mining products

The representative products are: tungsten steel road digging teeth/road digging teeth, tungsten steel gun bits, tungsten steel drill bits, tungsten steel drill bits, tungsten steel DTH drill bits, tungsten steel roller cone bits, tungsten steel coal cutters Teeth, Tungsten Steel Hollow Bit Teeth, etc.

Wear-resistant material

Tungsten steel sealing ring, tungsten steel wear-resistant material, tungsten steel plunger material, tungsten steel guide rail material, tungsten steel nozzle, tungsten steel grinding machine spindle material, etc.

Tungsten steel material

The academic name of tungsten steel material is tungsten steel profile, typical representative products are: tungsten steel round bar, tungsten steel strip, tungsten steel disc, tungsten steel sheet, etc.