Effect of plasma nitriding on M50 NiL steel – A review

Abstract

Chemical Diffusion Process like Nitriding has important role in modern surface hardening. Plasma nitriding is one of the best method to improve surface hardness, wear and corrosion resistance of material, and also plasma nitriding improves surface properties. M50 NiL Steel is a low carbon high alloy steel with good strength, hardness, and wear and corrosion resistance at elevated temperatures. It is frequently utilised in the aerospace sector due to its unique features. To determine the corrosion and wear resistance of double element alternate implanted M50 NiL steel, detection methods such as scanning electron microscopy (SEM), X-Ray diffraction method (XRD), transmission electron microscopy (TEM), and potentio dynamic polarisation were utilised. The purpose of this paper is to identify the effects of plasma nitriding on M50 NiL Steel and to know the progress of surface hardening properties like micro hardness and wear for M50 NiL steel after plasma nitriding. The bearing made out of this steel is operated under heavy loads and high speeds in air craft engine. Effects of nitriding temperature on microstructure, micro hardness, and wear resistance of nitride layers with only a diffusion layer and no standard compound layer. and surface hardness is improved at low nitriding temperatures, When the nitriding temperature exceeds 575 °C, the nitride layer thickness increases, while the core and surface micro hardness drops. Mechanical Properties of nitride surfaces are studied by using Vickers hardness test and polarization tests. M50 NiL Steel was Plasma nitro carburized at low temperature and rare earth (RE) atoms are diffused into the specimen surface for better surface hardness and increased corrosion resistance. Some times to achieve exceptional properties duplex hardening is preferred and this process can be useful to obtain good hardness and same can be done for both hardened and case hardened bearing steels, with relative increase in rolling contact fatigue resistant and better tribological properties.