Enhanced wear and corrosion resistance of AISI-304 steel by duplex cathodic cage plasma treatment

Abstract

The austinite stainless steel is widely employed in several industries due to exceptional corrosion resistance. Unfortunately, their use is restricted due to low surface hardness and poor wear resistance. The aim of this work is to improve the wear and corrosion resistance of AISI-304 steel using duplex cathodic cage plasma nitriding method. The duplex treatment is carried out in a two-step process using an alternative combination of aluminium and austinite stainless steel cathodic cages, with a process duration of 1 and 4 h, respectively. The results of duplex treatment samples (first processed by an aluminium cathodic cage (pre-Al CC) and in reverse order (post-Al CC)) are compared with single aluminium, and austinite stainless steel cathodic cage treated samples. The hardness-indentation depth profile illustrates the significant improvement in hardness by post-Al CC nitrided sample, and a strong dependence on processing order is observed. The aluminium nitride is found to be leading phase in the post-Al CC sample, which is probably responsible for significant hardness improvement. Particularly for post-Al CC treated sample, the wear rate and corrosion rates are dramatically reduced by processing. This study shows that duplex treatment with a particular processing specific order is highly beneficial for mechanical, wear and corrosion properties of the sample under consideration. The use of a single processing unit for both treatments, better surface uniformity, low-processing temperature, short combined treatment time and industrial compatibility of the system suggest the suitability of the technique for industrial applications.