Aiming to produce a pattern on the surface of austenitic stainless steel, AISI 316L, cylindrical samples were plasma nitrided with copper grids (the same are used in Transmission Electron Microscopy (TEM)) accommodated on the surface. Samples were positioned at the cathode and process was performed according to following constant parameters: temperature of 400 °C, pressure of 3 Torr and treatment time of 2h. In order to evaluate the difference in the pattern produced, three different gas

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... s were used: poor in nitrogen (5% N2/95% H2), rich in nitrogen (95% N2/5% H2) and a gas mixture with addition of argon (80% N2/10% H2/10% Ar). After nitriding, samples were characterized by optical interferometry (OI), scanning electron microscopy (SEM), optical microscopy (OM), micro hardness test and, X-ray diffraction (XRD). The results showed the presence of a mask (TEM grid) promotes the surface patterning of steel. This patterning is associated with high residual compressive stress induced by the introduction of a large amount of nitrogen.