Influence of low energy–high flux nitrogen implantation on the oxidation behavior of AISI 304L austenitic stainless steel

Abstract

Investigation of low-pressure elevated-temperature plasma immersion ion implantation of AISI 304 stainless steel Nitrogen and boron implantation into austenitic stainless steel Microstructure and corrosion resistance of plasma source ion nitrided austenitic stainless steel Low energy-high flux ͑1.2 keV, 1 mA/cm 2 ͒ nitriding of an austenitic AISI 304L stainless steel has been carried out by implanting a dose of 3.5ϫ10 19 ions cm Ϫ2 at 400°C for 1 h. An important increase in surface hardness has been found to occur as a result of the formation of the so-called expanded austenite ␥ N phase. Transmission electron microscopy studies have also shown the existence of hexagonal Cr 2 N precipitates at the nitrided layer/matrix interfacial region. The oxidation behavior has been then studied in the temperature range between 400 and 550°C for 24 h under synthetic air. It is shown that nitridation slightly modifies the oxidation kinetics as a result of the progressive transformation of the ␥ N phase towards CrN precipitation and ␣-FeNi matrix formation. More chromium enriched scales are, anyhow, developed on the nitrided steel than in the untreated one. These results are discussed on the basis of the chromium diffusion in the nitrided layer and its preferential chemical bonding with nitrogen atoms.

Low energy–high flux nitrogen implantation of an oxide-dispersion-strengthened FeAl intermetallic alloy

“…In typical austenitic matrices, nitridation leads to the appearance of a metastable γ N phase [28][29][30].…”

Oxidation mechanisms of low energy-high flux nitrided ODS FeAl intermetallic alloy

“…[11]. Under these experimental conditions, a several microns thick layer containing about 20 at% N was obtained in a stainless steel [12].…”

Effect of Nitriding Time on the Structural Evolution and Properties of Austenitic Stainless Steel Nitrided Using High Power Pulsed DC Glow Discharge Ar/N2 Plasma

“…Moreover, some grains of the 1-hour nitrided surface exhibit fine straight lines (Fig. 6a, arrowed), indicating slip bands caused by plastic deformation taking place in the nitride layer [46][47][48] . Such slip bands were not observed on the surface of the 3-hour nitrided sample possiblly due to the time affecting micro-milling or sputtering etching that modified the surface smoothness resulted the surface slip bans invisible.…”