NISCAIR Online Periodicals Repository

Research Journals >
Indian Journal of Chemical Technology (IJCT) >
IJCT Vol.12 [2005] >
IJCT Vol.12(3) [May 2005] >

Title: Microstructural and corrosion studies of 9Cr-1Mo steel in acidic methanol solutions
Authors: Singh, V B
Gupta, Archana
Keywords: Corrosion
9Cr-1Mo steel
potentiostatic technique
potentiodynamic technique
Issue Date: May-2005
Publisher: CSIR
IPC CodeC22C38/00
Abstract: The corrosion behaviour of 9Cr-1Mo ferritic steel has been studied in methanol containing different concentrations of sulphuric, hydrochloric acids and their mixtures using potentiostatic and potentiodynamic techniques at 30 °C. The influence of various heat treatments: furnace cooled (FC), air cooled (AC) and water quenched (WQ) on the electrochemical polarization behaviour has also been studied for a few selected compositions of these acids and their mixtures in methanolic solutions. The cathodic reaction is observed to be hydrogen evolution. The alloy showed active, passive and transpassive behaviour in different concentrations of sulphuric acid in methanol. The anodic polarization curves of the alloy revealed a characteristic ‘cathodic loop’ in methanol at higher concentrations of sulphuric acid (0.1 and 1.0 M). Stable passivity was also observed which became ustable at higher potential due to pitting. Well defined anodic Tafel region followed by a limiting current density region, in different concentrations of methanolic solution of hydrochloric acid, was observed. However, in the mixture of different concentrations of sulphuric acid and hydrochloric acids in methanol and at higher concentration of sulphuric acid (1.0 M) the alloy showed active, passive and transpassive behaviour. Such behaviour was not observed below 1.0 M concentration of either acid in methanol, rather a limiting nature was observed. It seems that in the acidic mixture, the SO2-4 ions act as inhibitor and decreases the adsorption of Cl- ions and at sufficiently high concentration it effectively hinders the adsorption of the Cl- ions on the surface. The anodic polarization curves for FC specimen shifted towards higher current density region and the curves for AC and WQ specimens shifted towards lower current density region in comparison to as-received one in methanolic solution of sulphuric acid. However, the anodic polarization curves for FC, AC and WQ specimen shifted towards higher current density region as compared to as-received specimen in methanolic solution of hydrochloric acid and in the mixture of hydrochloric and sulphuric acids in methanol. Examination of the sample surface was done using scanning electron microscopy (SEM).
Page(s): 347-355
ISSN: 0975-0991 (Online); 0971-457X (Print)
Source:IJCT Vol.12(3) [May 2005]

Files in This Item:

File Description SizeFormat
IJCT 12(3) 347-355.pdf624.27 kBAdobe PDFView/Open
 Current Page Visits: 159 
Recommend this item


Online Submission of Articles |  NISCAIR Website |  National Knowledge Resources Consortium |  Contact us |  Feedback

Disclaimer: NISCAIR assumes no responsibility for the statements and opinions advanced by contributors. The editorial staff in its work of examining papers received for publication is helped, in an honorary capacity, by many distinguished engineers and scientists.

CC License Except where otherwise noted, the Articles on this site are licensed under Creative Commons License: CC Attribution-Noncommercial-No Derivative Works 2.5 India

Copyright © 2015 The Council of Scientific and Industrial Research, New Delhi. All rights reserved.

Powered by DSpace Copyright © 2002-2007 MIT and Hewlett-Packard | Compliant to OAI-PMH V 2.0

Home Page Total Visits: 168173 since 01-Sep-2015  Last updated on 29-Jun-2016Webmaster: