Appraisal of Surface Modified AISI 316 L Stainless Steels by Plasma and Solid Nitriding Techniques

Abstract

AISI 316 L stainless steels type was surface modified by ion and solid nitriding treatment. It was demonstrated that a surface activation pretreatment in samples based in acid mixture accompanied with NH 4 NO 3 solution inside the container, can produce an efficient nitrogen diffusion process. As compared with ion nitriding treatment (20%N 2 -80%H 2 ), the samples were treated with solid nitriding technique, using Fe4KCN based compound at the same time and temperature (6 h and 500 ° C respectively). Superficial layers with a depth of 45 μm average were obtained with six hours treatment. Hardness surface values of two surface treatments present an increased value of approximately three times with respect to the matrix sample. Wear evaluation indicated low regimes of weight losses for both treatments. Oxidative-adhesive result is to be the predominant operating wear mechanism. Positive results were obtained in solid nitriding technique as compared with the expensive ion nitriding technique.