DESENVOLVIMENTO DO PROCESSO DE NITRETAÇÃO E PÓS OXIDAÇÃO A PLASMA DO AÇO AISI H13 PARA TRABALHO A QUENTE AISI H13 NO APERFEIÇOAMENTO DE EQUIPAMENTOS APLICADOS NO ARRANJO PRODUTIVO LOCAL

Abstract

The plasma nitriding process has been applied in various sectors of the industry, such as in plastic injection molds, aluminum, the automotive industry, or any other need for steel with high surface hardness and wear resistance, while maintaining good toughness and mechanical strength of the component. In response to the need for increased corrosion resistance in activities subjected to degrading environments, the plasma post-oxidation treatment carried out immediately after nitriding emerges as a solution to the problem. This article aimed to study the chemical composition and variation in the time of the plasma post-oxidation process of H13 steel components. The goal was to assess the formation of iron oxides (magnetite and hematite), analyzing their characteristics and applications, as well as evaluating variations in oxide intensity and oxidized layer thickness as a result of longer test durations. Following the treatments, the nitrided layer exhibited a thin white layer and a diffusion layer of 350 μm. After the post-oxidation treatment, the layer oxidized for 45 minutes had a thickness of approximately 5 μm, while the treatment conducted for 90 minutes resulted in a 10 μm layer. Through Vickers microhardness and X-ray diffraction (XRD) tests, the oxidation of iron nitrides was noticeable, allowing for the formation of an oxidized layer.