Comparison of carbonitriding and nitrocarburising on size and shape distortion of plain carbon SAE 1010 steel

Abstract

Carbonitriding is a widely accepted method of heat treatment used by North American manufacturers for plain carbon steel. While the process imparts a hard, wear resistant case, it is also associated with both size and shape distortion, which can be problematic for components in tight fitting assemblies. This research compares the effects of the carbonitriding and nitrocarburising processes on SAE 1010 steel with respect to residual stress and distortion. Results indicate that the two processes develop residual compressive stresses and are associated with both size and shape distortion. Although the magnitude of the compressive stresses in nitrocarburised steels is lower, this process was noted to give rise to overall smaller dimensional changes than the carbonitriding process. The findings from this study are applied to a manufacturing application involving the surface treatment of a thin shelled automotive component in a light loading application.