Nitriding method and device

摘要

A pulse voltage having a frequency of 15 kHz is applied from a discharging power supply unit ( 48 ) to between a crankshaft ( 12 ) and an electrode plate ( 45 ) at a current density of 2.5 mA/cm2 to generate a glow discharge and an electric heater ( 34 ) is driven at a 40% output (64 kW/kg) to heat the crankshaft ( 12 ) to up to 400° C., and then heating is continued with the current density of a glow discharge set at 0.5 mA/cm2 and the output of the electric heater ( 34 ) set at 90% (144 kW/kg), thereby effecting nitriding at a desired nitriding temperature.