Influence of nitriding on corrosion resistance of martensitic X17CrNi16‐2 stainless steel

Abstract

Nitriding increases surface hardness and improves wear resistance of stainless steels. However, nitriding can sometimes reduce their corrosion resistance. In this paper, the influence of nitriding on the corrosion resistance of martensitic stainless steel was investigated. Plasma nitriding at 440°C and 525°C and salt bath nitrocarburizing were carried out on X17CrNi16-2 stainless steel. Microhardness profiles of the obtained nitrided layers were examined. Phase composition analysis and quantitative depth profile analysis of the nitrided layers were preformed by X-ray diffraction (XRD) and glow-discharge optical emission spectrometry (GD-OES), respectively. Corrosion behaviour was evaluated by immersion test in 1% HCl, salt spray test in 5% NaCl and electrochemical corrosion tests in 3.5% NaCl aqueous solution. Results show that salt bath nitrocarburizing, as well as plasma nitriding at low temperature, increased microhardness without significantly reducing corrosion resistance. Plasma nitriding at a higher temperature increased the corrosion tendency of the X17CrNi16-2 steel.Keywords: Martensitic stainless steel / salt bath nitrocarburizing / plasma nitriding / corrosion resistance / X-ray diffraction Schlüsselwörter: Martensitischer Stahl / Salzbadnitrocarburieren / Plasmanitrieren / Korrosionsbeständigkeit / Röntgenbeugung

Nitrogen enrichment of AISI 409 stainless steel by solution heat treatment after plasma nitriding

“…However, it was restricted to the composite layer (50 µm). Similar hardened layers (1200 HV 0.05 /11.77 GPa, 30 µm) were obtained by Cajner et al [13] in an X17CrNi16-2 (martensitic) steel but with an unwanted core softening, caused by tempering effect. Contrasting with as-nitrided samples, SHTPN led to a surface hardness of 580 HV (5.69 GPa), which is almost constant along the first 200 µm.…”

“…As can be seen, the precipita- tion of chromium nitrides in the nitrided sample, confirmed by the XRD patterns, resulted in a less noble corrosion potential and an increase of current density, which consequently led to a higher corrosion rate. Cajner et al [13] observed the same corrosion behavior in plasma nitrided martensitic steel and attributed it to chromium nitride precipitation. Despite changing from ferrite to nitrogen martensite, the corrosion behavior shows small changes if compared with untreated steel, except for a reduction of pitting corrosion potential.…”

Structure and Properties of Gas-Nitrided, Precipitation-Hardened Martensitic Stainless Steel

“…There are literature studies on the corrosion and wear properties of nitrided layers on martensitic stainless steels hardened by carbon [ 7 , 14 , 15 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ] and 17-4 PH [ 24 , 39 ] steel, but the data on the performance of nitrided Nanoflex steel are practically unavailable.…”

Investigation on the Relationship between the Surface Chemistry and the Corrosion Resistance of Electrochemically Nitrided AISI 304 Stainless Steel

“…Nitriding plays a central role in this scenario, giving more versatility to the nitrogen content that can be added to austenitic stainless steels [18]. Plasma nitriding has gained increased technological relevance as a large-scale processing method to achieve nitrogen-rich stainless steel surfaces [19][20][21]. Recently, electrochemical nitriding has emerged as an alternative route to incorporate nitrogen into the surface of stainless steels [22].…”