The effect of a coating heat-treatment on Cr-Si and heat-treatment on the mechanical properties of Cr17Ni2 stainless steel

The in-situ co-deposition of Cr-Si into Cr17Ni2 stainless steel (similar to AISI 431) was achieved using a pack cementation process. Through the optim um parameters, a coating containing approximately 27 wt.% Cr and 2 wt.% Si was obtained, with a layer thickness of approximately 120 mum. Studies show ed that the thermal treatment of the coating resulted in a reduction of ten sile strength, but the improvement of impact toughness, although the coatin g had little effect on the mechanical properties of the bulk. Tempering at 300 or 450 degreesC improved the tensile strength and the impact toughness of the steel at 9 and -55 degreesC, while tempering at 550 degreesC reduced these mechanical properties. (C) 2000 Published by Elsevier Science S.A. A ll rights reserved.