Middle-frequency smelting stove; Quenching equipment; Vacuum stove; Diathermic furnace; high frequency smelting furnace; KGPS series transistor intermediate frequency power supply; IGBT supersound full solid state high frequency power supply; Vacuum sintering furnace; Vacuum smelting furnace; intermediate frequency heat-treating facility; surface hardening machine tool; medium-high frequency power source fittings of electric stove