PSI - Issue 14

A. Poonguzhali et al. / Procedia Structural Integrity 14 (2019) 705–711 Poonguzhali et al. / Structural Integrity Procedia 00 (2018) 000–000

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4. Conclusions The critical pitting potential (E pit ) and the passivity range drastically decreased and corrosion current density increases with an increase in chloride concentration as a function of CW. Fatigue behaviour of SS316LN as a function of cold work has been evaluated in acidified chloride medium. At high mean stress regime 20% CW showed beneficial effects on the fatigue life, while at lower mean stress, the marginal effect of CW is seen with respect to fatigue life. The duality in the fatigue life is due to the conjoint influence of an increase in yield strength and crack initiation mechanism which was in the mixed mode. LRS studies show oxides, hydroxides and oxyhydroxides formed on the surface of the fatigue tested specimen in proportion to their CF resistance These observations are supported by the fractographic examination. From AFM examination of fatigue tested sample revealed the slip offset was high for as received, while the not much significant difference between 5% and 20 % cold worked material at low mean stress levels. Kamachi Mudali, U., Shankar, P., Ningshen, S., Dayal, R.K., Khatak, H.S., Baldev Raj, 2002. On the pitting corrosion resistance of nitrogen alloyed cold worked austenitic stainless steels . Corrosion Science 44, pp. 2183-2198. Lameche S., Nedjar R., Rebbah H., Adjeb A., 2006. Effect of Temperature on the Pitting of three Stainless Steels in Chloride Containing Solutions. Journal of Corrosion Science and Engineering 7, pp. 104-110. Oblonsky L.J., Devine T.M., 1995. A surface enhanced Raman spectroscopic study of the passivefilms formed in borate buffer on iron, nickel, chromium and stainless steel. Corrosion Science 37, pp. 17-41. Poonguzhali A., Pujar M.G., and Kamachi Mudali U., 2015. Corrosion fatigue behaviour of 316LN SS in acidified sodium chloride solution at applied potential. The journal of the minerals, metals and materials society 67(5), pp. 1162-1175. Poonguzhali A., Pujar M.G., Mallika C. and Kamachi Mudali U., 2016. Characterization of microstructural damage due to corrosion fatigue in AISI Type 316 LN stainless steels with different nitrogen contents. Corrosion Engineering, Science and Technology 22, pp. 1-8. Qian Y.R., and Cahoon J.R., 1997. Crack Initiation Mechanisms for Corrosion Fatigue of Austenitic Stainless Steel, Corrosion 53, pp. 129 135 Sedriks A.J., 1985. In: Proceedings of the International Conference on Stainless Steels 85, The Institute of Metals, London, pp. 125. Walter J. Tobler, 2004. Influence of molybdenum species on pitting corrosion of stainless steels. Ph.D Diss, Swiss Federal Institute of Technology, Zurich. pp. 1-215. . References