The invention provides an induction
quenching process for hardening an
alloy cast iron camshaft by using
compressed air, which comprises the following steps: S1, preheating is carried out: the
camshaft is heated to 180-210 DEG C in an induction manner in a first stage, heating is suspended for 2-5 seconds, in a second stage, after the
camshaft is inductively heated to 550-600 DEG C, heating is suspended for 2-5 seconds, and in a third stage, after the camshaft is inductively heated to 810-850 DEG C, heating is suspended for 2-5 seconds, wherein the heating rates of the three stages are all 40-50 DEG C / s; S2, heating to a
quenching temperature is carried out:
induction heating is carried out on the camshaft preheated in the step S1 to 900-940 DEG C at a heating rate of 40-50 DEG C / s; S3,
quenching is conducted, specifically,
compressed air with the pressure of 0.4-0.5 MPa is adopted as a quenching medium to quench the camshaft, and the camshaft is cooled to 250-300 DEG C; and S4, afterheat
tempering is carried out. The
alloy cast iron camshaft product quenched by using the process method disclosed by the invention does not crack in the quenching process, and the
hardness index of the quenched
alloy cast iron camshaft product can meet the technical requirements, so that the
rejection rate of the product is reduced, and the production cost is greatly saved.