A STUDY OF ESSENTIAL PARAMETERS ON GAS CARBURIZING OF AISI 8620 (Ni-Cr-Mo) ALLOY STEEL

Abstract

Carburizing of steel components is an essential process in the automotive industry especially for heavy load bearing machine parts such as gear teeth, pinions, crank and camshafts. Carburizing is used to induce carbon in the steel component and the final part has a surface of higher carbon content whereas the core remains soft, thus making it to bear heavy loads. In this paper effect of physical and chemical parameters in gas carburizing atmosphere furnace were observed. Various samples of 8620 steel were carburized in different furnaces for discrete time periods and temperatures followed by water, oil quenched and tempered. The gas carburized samples were characterized performing different tests like impact, hardness and metallographic. Any changes in properties were determined. It was concluded that for optimum carburizing of 8620 alloy steel with a case depth of 1 mm after carburizing the samples, the temperature in the furnace should be lowered to 830◦C before quenching in oil medium to avoid distortion.