How to choose the induction heating current frequency for different hardened layer depths ?

The current frequency selection principles of induction heating furnace for parts with different hardening layer depths and different diameters are mainly as follows, namely, the diameter of the parts is preferably more than 4 times the current penetration depth in the hot state, and the inductor has high electrical efficiency at this time; The penetration depth of the current in the hot state is preferably about 2 times the depth of the hardened layer of the part. At this time, penetration heating is used, and the thermal efficiency is high. The current frequency required for different hardened layer depths is shown in Table 2.10.

Table 2-10 Current frequency required for different hardened layer depths

Note: 1-high efficiency, 2-lower efficiency, 3-not suitable.