METHOD OF RECONDITIONING PISTON PINS MADE OF STEEL CEMENT GRADES OF AUTOMOTIVE ENGINES Russian patent published in 1998 - IPC

FIELD: mechanical engineering, repairs of machines. SUBSTANCE: method includes heating of piston pins above point Ac3 and cooling from inside with quenching medium. In this case, as distinguished from the known analogous methods, after heating, cooling is carried out additionally in the air to temperature below point Ar1 by 50-60 C, and additional thermocyclic treatment is carried out by multiple heating above point Ac1 by 25-50 C and cooling down to below point Ar1 by 50-80 C and final cooling with quenching medium from inside with temperature Ac1 (20-50 C). The method allows employment of classic (gradual) method of heat treatment of steel cement grades, rational application of thermocyclic treatment. Combination of employed procedures in the process results in qualitatively new properties of reconditioned piston pins that increased their service life after reconditioning. EFFECT: higher quality of articles and prolonged service life of reconditioned piston pins. 1 dwg