Heat treatment process and characteristics of tempering steel with high-frequency induction heating equipment

Tempering is mostly performed immediately after quenching. The purpose of tempering the workpiece is to eliminate the residual stress generated during quenching of the workpiece, stabilize the size of the workpiece, ensure the accuracy of the workpiece, and improve the processing performance. Therefore, tempering is the last step for the workpiece to obtain the required performance. An important process. Today, let’s talk about the classification and characteristics of the tempering process of steel using high-frequency induction heating equipment for tempering heat treatment.

When steel is tempered with high-frequency induction heating equipment, according to the tempering temperature, the induction heating tempering process can be divided into three tempering processes: low temperature tempering, medium temperature tempering and high temperature tempering. Let us first understand the different heating processes. Methods Tempering process of quenched steel.

When carbon steel is tempered at different temperatures after quenching with high-frequency induction heating equipment, the characteristics of the tempered structure formed by martensite decomposition are as follows:

(1) Low temperature tempering structure. When the induction heating tempering temperature is 250 to 400°C, the quenched martensite decomposes into a complex mixed structure composed of fine carbide precipitates and ferrite. This mixed structure maintains the shape of lath-like martensite, which is called tempering. Fire martensite. Tempered martensite has the characteristics of high hardness, high strength and low toughness.

(2) Medium temperature tempered structure. When the induction heating tempering temperature is 400 to 600°C, the ferrite grains begin to grow and the fine cementite begins to aggregate and grow, both of which still maintain the shape of lath martensite. The mixed structure composed of two phases is called tempered troostite. Tempered trostenitic steel shows high elastic limit, yield limit and good toughness.

(3) High temperature tempering structure. When the induction heating tempering temperature is 600~750°C, the carbon content in the ferrite increases, reaches a balanced composition and begins to transform from flaky to equiaxed grains, and the flaky cementite grows into large grains. This complex phase structure composed of equiaxed grain ferrite and coarse cementite is called tempered sorbite. Tempered troostite steel shows excellent comprehensive properties, including both certain strength and hardness, as well as good plasticity and toughness.

It can be seen that different tempering processes produce different tempered structures. Different tempering structures have different tempering characteristics. Different tempering structures are suitable for different steel types. Zhengzhou Gou's is a manufacturer specializing in the manufacturing and sales of induction heating equipment. The high-frequency induction heating equipment and other equipment it produces are recognized by the majority of users, and it also has considerable experience in the heat treatment of workpieces. If you have anything to know about this, please feel free to call us.