Plasma nitriding is very effective in removing the passive layer of chromium oxide formed naturally on the surface of stainless steel, but controlling the kinetics is key for optimal results.

NitrideTool software, developed by the the Center for Heat Treating Excellence (CHTE), simulates the gas nitriding of steels to understand nitriding potential, temperature, time, and surface condition.

The Australian Research Council is funding a new training center in Surface Engineering for Advanced Materials (SEAM) based in Melbourne, Australia. This article describes the research, development, and educational objectives of the new center, which aims to solve crucial surface engineering problems, such as their design, fabrication, testing, analysis, and pathways towards value-added applications.

Low-temperature surface hardening of stainless steel by means of gaseous processing provides a high degree of tailorability of the hard surface case without affecting corrosion resistance. This article covers the fundamental and technological aspects of the process and examines the effect of different LTSH treatments on 304 and 316 austenitic stainless steel.

Active screen plasma nitriding and nitrocarburizing are relatively new processes in which a plasma discharge is applied to a metal screen surrounding the workload, generating highly reactive gas species that flow to the component surface. The active screen also radiates heat, resulting in a uniform temperature throughout the load. This article provides an overview of the two processes and presents examples of their use on stainless steel piston rings (nitriding) and 4142 and 1045 steels (nitrocarburizing).

Vacuum solution nitriding is a promising technique for increasing the surface hardness, load-bearing capability, and fatigue strength of martensitic stainless steels without sacrificing corrosion resistance. This article examines the effects of nitriding pressure and temperature on surface nitrogen content and case depth in four martensitic stainless steels.

In this study, 316L stainless steel samples were plasma nitrided for 64 h at 370-420 °C then subjected to surface hardness and pitting corrosion testing. The results show that interstitial hardening with nitrogen significantly improved the surface hardness as well as the pitting corrosion resistance of the austenitic stainless steel.

This work describes the development of a model to simulate the compound layer growth kinetics for nitriding AISI 4140 steel based on a customized Lehrer diagram. The model can be used to calculate concentration profiles of nitrogen as a function of time and position during the nitriding process and to predict the thickness of the compound layer. Winner of the 2012 HTS-Bodycote Best Paper in Heat Treating Award endowed by Bodycote Thermal Process-North America.