Microstructural Changes Induced during Hydrogen Charging Process in Stainless Steels with and without Nitrided Layers

Abstract:

The purpose of this study is to analyze the effect of glow discharge nitriding on hydrogen degradation of two types of steels: two-phase austenitic-ferritic and single-phase austenitic. The nitriding process resulted in formation of surface layers composed of expanded austenite (S phase), and in the case of two-phase steel of expanded austenite and expanded ferrite. Microstructural changes occurring under the influence of hydrogen on steels without and with nitrided layers were investigated with the use of scanning (SEM) and transmission (TEM) electron microscopy techniques. It was shown that the density of cracks formed during cathodic hydrogen charging is higher on the surface of the non-nitrided steels compared to the nitrided steels after identical hydrogen charging process. Moreover in non nitrided steel hydrogenation leads to considerable increase of dislocation density, which results from the high concentration of hydrogen absorbed to the steel during its cathodic charging. This leads in turn to high stress concentration and local embrittlement giving rise to cracks formation. Conversely nitriding reduces the absorption of hydrogen and prevents structural changes resulting in hydrogen embrittlement. The conducted studies show that glow discharge nitriding can be used to increase resistance to hydrogen embrittlement of austenitic and austenitic ferritic stainless steels.

• Periodical: Solid State Phenomena (Volume 186)
• Pages: 305-310
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.186.305
• Online since: March 2012
• Authors: Bartosz Gołębiowski, Wiesław Świątnicki
• Keywords: Hydrogen Charging, Microstructural Changes, Nitriding, Stainless Steel (SS), Surface Layer

References

[1] A.A. El-Yazgi, D. Hardie: The embrittlement of a duplex stainless steel by hydrogen in a variety of environments, Corros. Sci. 38 (1996) 735-744.

DOI: 10.1016/0010-938x(95)00162-d

[2] R. Oltra, C. Bouillot, T. Magnin: Localized hydrogen cracking in the austenitic phase of a duplex stainless steel, Scripta Mater. 35 (1996) 1101-1105.

DOI: 10.1016/1359-6462(96)00293-x

[3] A.A. El-Yazgi, D. Hardie: Stress corrosion cracking of duplex and super duplex stainless steels in sour environments, Corros. Sci. 40 (1998) 909-930.

DOI: 10.1016/s0010-938x(98)00022-5

[4] S.T. Tsai, K.P. Yen, H.C. Shih: The embrittlement of duplex stainless steel in sulfide-containing 3.5 wt% NaCl solution, Corros. Sci. 40 (1998) 281-295.

DOI: 10.1016/s0010-938x(97)00135-2

[5] W.C. Luu, P.W. Liu, J.K. Wu: Hydrogen transport and degradation of a commercial duplex stainless steel, Corros. Sci. 44 (2002) 1783-1791.

DOI: 10.1016/s0010-938x(01)00143-3

[6] T. Zakroczymski, A. Glowacka, W Swiatnicki: Effect of hydrogen concentration on the embrittlement of a duplex stainless steel, Corros. Sci. 47 (2005) 1403-1414.

DOI: 10.1016/j.corsci.2004.07.036

[7] A. Głowacka, A. Gołaszewski, W.A. Świątnicki: Hydrogen Embrittlement of Austenitic-Ferritic Steel, Material Engineering (Inżynieria Materiałowa). XXVIII, 3-4 (2007) 768-773.

[8] W. Świątnicki: The role of hydrogen induced microstructural changes in the embrittlement of austenitic-ferritic steel, in: B. Somerday, P. Sofronis, R. Jones (Eds.), Proc. 2008'Int. Hydrogen Conf. - Effects of Hydrogen on Materials, ASM International, 2009, pp.155-162.

[9] B. Gołębiowski, W.A. Świątnicki, M. Gasperini: Microstructural changes induced near crack tip during corrosion fatigue tests in austenitic – ferritic steel, Journal of Microscopy-Oxford. 237 (2010) 352–358.

DOI: 10.1111/j.1365-2818.2009.03259.x

[10] T.Michler, J. Nauman: Coatings to reduce hydrogen enviroment embrittlement of 304 sustenitic stainless steel, Surface and Coatings Technology. 203 (2009) 1819-1828.

DOI: 10.1016/j.surfcoat.2009.01.013

[11] T. Zakroczymski, N. Lukomski, J. Flis: The effect of plasma nitriding-base treatments on the absorption of hydrogen by iron, Corros. Sci. 37 (1995) 811-822.

DOI: 10.1016/0010-938x(95)80011-5

[12] Z. Wolarek, T. Zakroczymski: Hydrogen absorption in plasma-nitrided iron, Acta Mater. 54 (2006) 1525-1532.

DOI: 10.1016/j.actamat.2005.11.018

[13] B. Gołębiowski, M. Kamiński, W. Świątnicki: Badanie wpływu niskotemperaturowego azotowania jarzeniowego stali dupleks na jej odporność korozyjną po wodorowaniu, Material Engineering (Inżynieria Materiałowa). 4 (2010) 972-977.

[14] Bell, Surface engineering of austenitic stainless steel: Surface Engineering. 18 (2002) 415-422.

DOI: 10.1179/026708402225006268

[15] B. Gołębiowski, T. Zakroczymski, R. Sobiecki, W. Świątnicki: Characteristics of surface layers produced on austenitic-ferritic stainless steel by low temperature glow discharge nitriding, Inżynieria Materiałowa. 3 (2010) 320-323.

DOI: 10.4028/www.scientific.net/ssp.183.71