Tribocorrosion performance of 316L stainless steel enhanced by laser clad 2-layer coating using Fe-based amorphous powder

To improve the tribocorrosion performance of 316L stainless steel (SS), multi-layer (1, 2 and 3 layers) Fe-based alloy coatings were manufactured by laser cladding Fe-based amorphous powder on 316L SS, and the corrosive wear behavior was investigated against Alumina ball in Ringer's solution. With the increase of cladding layer number, the content of bodycentered cubic (BCC) phase increases, and the hardness also improved. The volume loss rate of SS at 5 N load decreased over 3 times by the 2-layer coating. Under 10 or 20 N loads, the 2-layer coating still presents the best tribocorrosion performance with the lowest values of friction coefficient and volume loss rate. The multi-layer cladding caused surface chemical composition change leading to the decrease of Cr accompanied with the increase of Mo and Y, which is responsible for the increase of BCC content and hardness as well as the formation of lubricant FeeCr hydroxide film. The friction induced lubricating film may facilitate to design new metallic coatings for the low carbon steels applied in corrosive environment.