Marikannu, C. and Sathiyanarayanan, S. and Venkatachari, G. (2005) Studies on newer chemical passivation treatment for stainless steel. Transactions of the Institute of Metal Finishing, 83 (3). pp. 158-160. ISSN 0020-2967

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Abstract

An attempt has been made to develop a chemical passivation treatment for AISI 304 stainless steel based on nitric acid in the presence of various oxidising agents such as sodium molybdate, potassium dichromate and potassium permanganate. The stability of the passive film formed through different chemical passivation treatments has been studied by potential–time measurement in 0.5 M sulphuric acid and the operating parameters of chemical passivation have also been optimised by this technique. Results of the study show that chemical passivation of stainless steel in nitric acid shifts the open circuit potential in the positive direction. Increase of concentration of nitric acid, treatment time and temperature further ennobles the potential. Addition of either dichromate or permanganate ions to nitric acid helps in forming a more stable passive film whereas molybdate, even at higher concentrations does not have any beneficial effect on passive film formation.

Item Type:	Article
Uncontrolled Keywords:	Passivation; Chemical treatment; Stainless steel; Nitric acid; Sulphuric acid
Subjects:	Corrosion Science and Engineering
Divisions:	UNSPECIFIED
Depositing User:	TTBD CECRI
Date Deposited:	18 Jan 2012 16:05
Last Modified:	18 Jan 2012 16:05
URI:	http://cecri.csircentral.net/id/eprint/226

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