Development of steel grades for heat treated power train components: a review

Abstract

The development of new carburising steel grades by Daido Steel for heat treated transmission parts is reviewed. These developments are driven by the need for cost reduction, weight saving, fuel economy and higher mechanical performance in new car models under development in response to environmental and economic demands. The next generation of gears will be peened, then vacuum carburised to improve fatigue and impact strength in lighter components designed with smaller tooth cross-sections, and new steels giving improved performance have been developed. Case studies of new steels for pulleys (allowing shorter carburising times) and constant velocity joints are also described.

Effects of gas carbonitriding process on surface characteristics of new hot working tool steel

“…Generally, case hardness is increased by diffusion of carbon and/or nitrogen into the surface, using thermochemical treatments (i.e. carburising,3,4 nitrocarburising2,5 and carbonitriding processes6 – 10).…”