heat treatment of ball valves

Heat treatment of the valve

Steel is the most widely used material in ball valve production, and this material can be controlled by heat treatment.

Heat treatment is a process method to change the internal organizational structure of the valve material through the process of heating, insulation and cooling, so as to improve its mechanical properties. Valve heat treatment is mainly divided into two categories: preliminary heat treatment and final heat treatment.

Pre-heat treatment

annealing: the valve material is heated above the austenitic transition temperature, and slowly cooled after holding for a certain time. Incomplete annealing can eliminate the internal stress of forging press, reduce hardness and improve toughness. Complete annealing can refine grain, improve machining properties and prepare microstructure for quenching.

Normalizing: the valve material is heated above the critical temperature and cooled rapidly after holding for a certain time. The purpose is to improve the hardness and wear resistance of the material. Aging treatment: It is mainly used to eliminate the internal stress generated in blank manufacturing and machining, and stabilize the processing accuracy of parts.

Tempering: After quenching, high temperature tempering treatment is carried out to obtain a uniform and fine tempered sorbite structure, which is prepared for subsequent surface quenching and nitride treatment to reduce deformation.

Final heat treatment

quenching: the valve is heated to a certain temperature after rapid cooling, so that its surface to form a high hardness of martensitic structure, significantly improve the hardness and wear resistance. There are two ways of quenching: surface quenching and integral quenching, of which surface quenching is widely used.

Tempering: the quenched valve is heated to a temperature lower than the phase change temperature, and is cooled to room temperature at a certain cooling rate after a certain period of time. The purpose is to eliminate the internal stress caused by quenching and improve toughness.

Nitriding treatment: Nitrogen atoms penetrate the valve surface to obtain a layer of nitrogen-containing compounds. Nitriding layer can improve the hardness, wear resistance, fatigue strength and corrosion resistance of the valve surface.

The above is the content of ball valve heat treatment. For the demand of ball valve customers can take the initiative to contact us, we are Yongjia Dalunwei valve co.,ltd, a research and development, production, sales and service for the ball valve manufacturer. Look forward to your consultation.