Abstract: The process here is characterized by its high power density. The high-frequency generator is controlled by micro-computer. Hardening processes are carried out on specimens of 45、GCr15 and T10A steels. The optimum process diagrams of steels 45 and GCr15 are established. Specimens give super-hardness and high residual compressive stress in the hardened case. The features of tempering and microstructure under TEM show that: effective grain refinement is mainly cause of super-hardness, high residual compressive stress and high density sub-structure have an important effect upon super-hardness.

Key words: Hardening, Induction heating, Surface quality