Influence of Tungsten on the Microstructure and Heat Treatment of Steel：

1. Tungsten is a refractory metal with the highest melting point (3387°C) and is in the same group as chromium and molybdenum in the periodic table. The behavior in steel is also similar to that of molybdenum, that is, it reduces the austenite phase region, and is a strong carbide forming element, partially dissolved in iron.

2. The effect of tungsten on the hardenability of steel is not as strong as that of molybdenum and chromium. The presence of special carbides of tungsten reduces the hardenability and hardenability of steel.

3. The special carbide of tungsten prevents the growth of steel grains and reduces the overheating sensitivity of steel.

4. Tungsten significantly improves the tempering stability of steel.

The influence of tungsten on the mechanical properties of steel：

1. Tungsten improves the tempering resistance of steel, and the carbide is very hard, thus improving the wear resistance of steel and making the steel have a certain degree of thermal hardness.

2. Improve the creep resistance of steel at high temperature, its effect is not as strong as molybdenum.

The influence of tungsten on the physical, chemical and technological properties of steel：

1. Significantly increase the density of steel and strongly reduce the thermal conductivity of steel.

2. Significantly improve the coercivity and residual magnetic induction of steel.

3. Tungsten has little effect on the corrosion resistance and high temperature oxidation resistance of steel, and the non-skinning property of tungsten-containing steel at high temperatures is significantly reduced.

4. Tungsten steel has low high temperature plasticity, high deformation resistance and poor hot workability.

5. High-alloy tungsten steel has segregation of fusible phases in the as-cast state, and the forging temperature is high, and it should prevent the high-carbon tungsten steel from causing black color breakage due to carbon graphitization.

Application of tungsten in steel：

Mainly used for tool steel, such as high-speed steel and hot forging die steel. When there are special needs, it is used in carburized steel and quenched and tempered steel.