Surface heat treatment refers to the process of heat-treating only the surface layer of steel castings. Surface heat treatment can also obtain the required metallographic structure and mechanical properties.
Commonly used surface heat treatment methods are: induction heating quenching, flame heating quenching, laser heat treatment, contact resistance heating quenching, electrolyte quenching, pulse heating heat treatment, etc. Through surface heat treatment, castings and other metal parts can obtain a surface layer that meets the performance requirements.
After the surface hardening layer is obtained by surface heating and quenching, the core of the casting can still maintain the original microstructure and performance, so as to achieve the excellent comprehensive performance of improving fatigue strength, improving wear resistance and maintaining toughness. At the same time, surface heat treatment can reduce energy consumption and at the same time reduce quenching deformation.
Induction hardening is a heat treatment process that uses the heat effect generated by the induction current through the workpiece to heat the surface of the casting, locally or as a whole, and then perform rapid cooling. The basic principles of induction heating are: electromagnetic induction, skin effect and heat conduction.
The Characteristics of the Induction Heating Quenching:
1) Induction quenching has superplasticity. The surface hardness of the workpiece is 2-3 HRC higher than that of ordinary quenching. After induction heating and quenching, the martensite of the casting is relatively small and the carbides are dispersed.
2) The wear resistance of the casting after induction heating quenching is higher than that of ordinary quenching.
3) Because the surface of the workpiece is fine cryptocrystalline martensite and there is compressive stress, the fatigue strength of the workpiece is greatly improved
4) The quality of the workpiece is stable and the deformation is small.
5) Fast heating speed and high thermal efficiency
6) High productivity, easy to realize mechanized production
Post time: Jul-13-2021