LOCAL HARDENING METHOD FOR BEARING PINS AND DEVICE FOR METHOD REALISATION Russian patent published in 2012 - IPC C21D1/10 C21D9/26 

FIELD: machine-building industry.

SUBSTANCE: pins are sequentially heated to 790-810°C above A_C3 point and then cooled down in not heated medical liquid petrolatum when they are freely dropped into the hardening tank with pressure head of medical liquid petrolatum ensuring martensitic transformations while pins drop freely. The distance between inductor coil and free surface of medical liquid petrolatum shall be within 10-12 mm. The method is implemented on a plant containing power source coupled with a loop inductor inducting wire as a double-stage bushing having groove for screening device installation. The plant also comprises a rotor in the form of a disc perforated for pins. The receiver bushings, sweep drive with dividing disc and fixing device located in axial alignment to the rotor, command unit as an eccentric shaft, a follower with micrometric screw for adjustment, device with a mirror and a desk with adjustment bolts to fix plate having oval holes for adjustment bolts are installed in the pins.

EFFECT: assured quality of pins if requirements of hardening area length and transition area are strictly followed and achievement of fine grain structure in hardened area of pin.

2 cl, 1 ex, 4 dwg