The purpose of brake camshaft quenching is to make the supercooled austenite martensite or bainite transformation, get martensite or bainite structure, and then with different temperature tempering, in order to greatly improve the strength, hardness, wear resistance, fatigue strength and toughness of steel, so as to meet the different requirements of various mechanical parts and tools.
Put the workpiece into the inductor (coil), when the inductor into a certain frequency of alternating current, the surrounding alternating magnetic field is generated. The electromagnetic induction of alternating magnetic field produces a closed induced current ─ eddy current in the workpiece. The induced current distribution on the workpiece section is very uneven, the workpiece surface current density is very high, gradually decreasing inward, this phenomenon is called skin effect. The electric energy of the high density current on the surface of the workpiece is converted into heat energy, which increases the temperature of the surface surface, that is, surface heating is realized. The higher the current frequency, the larger the current density difference between the workpiece surface and the inside, the thinner the heating layer. Surface quenching can be achieved by rapid cooling after the temperature of the heating layer exceeds the critical point temperature of the steel.
