The application possibilities of austenitic stainless steels in high friction, abrasion, and sliding wear conditions are limited by their inadequate hardness and tribological characteristics. In order to improve these properties, the thermochemical treatment of their surface by plasma nitriding is suitable. This article is focused on the corrosion resistance of conventionally plasma-nitrided AISI 304 stainless steel (530 °C, 24 h) in 0.05 M and 0.5 M sodium chloride solutions at room temperature (20 ± 3 °C), tested by potentiodynamic polarization and electrochemical impedance spectroscopy. Optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy are used for nitrided layer characterization. The experiment results confirmed the plasma-nitrided layer formation of increased micro-hardness related to the presence of Cr₂N chromium nitrides and higher surface roughness compared to the as-received state. Both of the performed independent electrochemical corrosion tests point to a significant reduction in corrosion resistance after the performed plasma nitriding, even in a solution with a very low chloride concentration (0.05 mol/L).

The application possibilities of austenitic stainless steels in high friction, abrasion and sliding wear conditions are limited by their inadequate hardness and tribological characteristics. In order to improve these properties, thermochemical treatment of their surface by plasma nitriding is suitable. This article is focused on corrosion resistance of the conventionally plasma nitrided AISI 304 stainless steel (530 °C, 24 hours) in 0.05 M and 0.5 M sodium chloride solutions at room temperature (20 ± 3 °C), tested by potentiodynamic polarization and electrochemical impedance spectroscopy. The optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy are used for the nitrided layer characterization. The experiment results point to a significant reduction in corrosion resistance after performed plasma nitriding even in a solution with a very low chloride concentration (0.05 mol/L).

The paper is aimed at establishing knowledge of the failure mechanisms and plastic behaviour of austenitic steel AISI 304 in the initial state under different loading conditions. Microstructural analysis was performed on a light microscope Neophot 32. AISI 304 austenitic steel has a microstructure formed by a large number of polyhedral austenite grains of different sizes. The steel microstructure, mechanical and fatigue properties, and areas of the plastic zone after the bending impact test were investigated. The surface hardness of samples was measured on a Zwick Roell ZHVµ microhardness measuring device using the Vickers method. After the bending impact test, fractures were formed with significant deformation with a typical pit morphology. The fatigue test, performed on a Zwick Roell resonant pulsator, monitored the plastic deformation causing changes in mechanical properties. Finally, fractographic evaluations of the fracture surfaces were performed on a Tescan Vega LMUII scanning electron microscope. The result of the work will demonstrate the differences in material behaviour under both static and cyclic loading.

This article deals with the influence of plasma nitriding and sensitization on the microstructure and microhardness of AISI 304 austenitic steel. The microstructure of AISI 304 austenitic steel in all states was observed on a Neophot 32 optica...

Hydrogen embrittlement involves the interaction between hydrogen and the microstructure of metals, which can lead to an alarming loss of mechanical properties. For advanced high-strength (AHS) steel S960MC grade, which finds application in fie...

Austenitic stainless steels are highly corrosion-resistant in common oxidation environments. However, aggressive chloride-containing solutions can evoke local corrosion, which performs an important risk in the safe use of these materials. This research deals with the effect of the solution annealing (1050 °C, 15 min) on the electrochemical parameters of AISI 304 and AISI 316L stainless steels. Corrosion resistance of the solution-annealed specimens is evaluated and compared to the as received specimens by the potentiodynamic polarization test performed in 1M pH neutral NaCl solution at the 20 ± 3 °C temperature. The obtained results did not clearly confirm the positive effect of solution annealing on corrosion resistance in the given aggressive solution. Although the pitting potentials indicating higher pitting corrosion resistance increased, the kinetics of the corrosion process intensified.