What is the heat treatment process and effect of tungsten steel round bar?

Heat treatment process and effect of tungsten steel round bar

Heat treatment is an important process link in the processing of tungsten steel round bar, which can improve the performance of steel and enhance its mechanical properties, wear resistance and corrosion resistance. Below we will introduce in detail the process flow of heat treatment of tungsten steel round bar and the effect of each process step on the material properties, hope to help you.

The heat treatment process of tungsten steel round bar generally includes the following steps: annealing, normalising and quenching.

1. annealing

Annealing is a heat treatment process in which the steel is heated to a certain temperature and then cooled appropriately to make changes in its organisation and properties. The main purpose of annealing is to eliminate the internal stress of steel, improve its plasticity and workability. Specific steps are as follows:

(1) Heating: put the tungsten steel round bar into the heating furnace and heat it at a slow speed. The heating temperature is generally 800~900℃, and the holding time is determined according to the thickness and diameter of the material, usually about 1 hour.

(2) Holding: The heated tungsten steel round bar is put into the insulated container for holding, the cooling speed is slower at room temperature, and the holding time is usually 2~3 hours to ensure the uniform temperature inside the steel.

(3) Cooling: the cooling speed has an important effect on the annealing effect. Generally use air cooling or oil cooling, slower cooling rate helps reduce internal stress and improve the plasticity of steel.

After annealing, the organisation of tungsten steel round bar becomes uniform and fine, the internal stress is released, the plasticity and toughness of the material is improved, and the machinability of the steel can be effectively improved.

2. Normalising

Normalising is a heat treatment process in which steel is heated and held at a higher temperature and then cooled more slowly to the ambient temperature, by which the organisation and properties of the steel can be changed to improve the hardness and strength of the steel. The specific steps are as follows:

(1) Heating: put the annealed tungsten steel round bar into the heating furnace, and the heating temperature is generally 800~900℃.

(2) Holding: the steel is held in the heating furnace for a certain period of time, the holding time is related to the size and thickness of the steel, usually 1~2 hours.

(3) Cooling: a slower cooling rate is used, usually the steel is removed from the furnace and cooled naturally in the air.

The organisation of tungsten steel round bar after normalising will undergo certain changes, and the grains will be refined, which improves the hardness and strength of the material. In addition, the normalising process can improve the dimensional stability and resistance to thermal expansion of the steel.

3. Quenching

Quenching is a heat treatment process in which steel is heated above a critical temperature and then rapidly cooled to room temperature. Quenching enables the organisation of the steel to form a martensitic structure, which increases the hardness and strength of the steel but reduces the toughness of the steel. The specific steps are as follows:

(1) Heating: the annealed tungsten steel round bar is put into the heating furnace with high heating temperature, generally at 900~1100℃.

(2) Holding: The holding time is short, according to the size and thickness of the material, generally 15~30 minutes.

(3) Cooling: the cooling speed of quenching is very fast, and the commonly used cooling medium includes oil, water, brine and so on. After quenching, a brittle shell will form on the surface of the tungsten steel round bar, and a martensitic organisation will form inside, which will increase the hardness of the material significantly.

Overall, the heat treatment process of tungsten steel round bar can improve the mechanical properties and wear resistance of the steel by changing its organisational structure, making it more suitable for specific industrial fields. Different heat treatment process steps will have different effects on the performance of steel, which need to be selected according to the specific application requirements and material properties. I hope the above content is helpful to you.