Papers by Keyword: Plasma Carburizing

Abstract: After being plasma carburized, the surface of AISI 316 austenitic stainless steel was covered with a layer of compact black thin-film. The surface polishing treatment, electrochemical brightening was carried out to remove the black thin-film and renew the original color of the stainless steel. The surface appearance, microstructures, micro hardness, surface roughness and corrosion resistance of the samples treated by electrochemical brightening process were analyzed. Experimental results show that the electrochemical brightening treatment can remove the black thin-film from and restore the original color of the plasma carburized stainless steel. After electrochemical brightening treatment, the thickness and surface hardness of the carburized layer were all decreased little, but the corrosion resistance was improved significantly. And the surface roughness (Ra) was lower than before. Therefore, the electrochemical surface brightening treatment can be used to improve the surface quality of the austenitic stainless steel treated by plasma carburizing.

Abstract: Plasma carburizing of AISI 316L austenitic stainless steel was carried out at low temperature to improve the surface hardness without degradation of its corrosion resistance. And the post-treatment, namely electrochemical surface brightening process was carried out to clear away a layer of thin black film on the plasma carburized samples and improve the surface quality of the hardened stainless steel. The surface appearance, roughness, microstructures, microhardness and corrosion resistance of the samples before and after brightening were analyzed and compared. Experimental results of plasma carburizing at low temperature showed that high-quality hardened layers can be produced at the appropriate process parameters.The electrochemical brightening process can be used as a post-treatment to restore the original color and further improve the corrosion resisitance of the plasma carburized stainless steel.

Abstract: Plasma carburizing of AISI 316L austenitic stainless steel was carried out at low temperature to improve the surface hardness without degradation of its corrosion resistance. The microstructure, surface hardness, phase composition and corrosion property of the hardened layer were analyzed. The experimental results show that high-quality hardened layers can be produced at the carburizing temperatures between 673 K and 773 K, which have not only high surface hardness and wear resistance, but also good corrosion resistance. All of the hardened layers display a precipitation-free structure or Sc phase. The chromium carbides began to precipitate in the hardened layer as soon as the carburizing temperature is higher than 823 K. The precipitation of chromium carbides will lead to deterioration in corrosion resistance of the hardened stainless steel.