Abstract

Electrochemical techniques were applied to study the crevice corrosion resistance of two types of stainless steel alloys namely, conventional 316L and super austenitic 6% Mo in acidified 3% NaCl solution at room temperature. Potentiodynamic results showed that 6% Mo alloy possessed a remarkable resistance to crevice corrosion compared to 316L alloy when tested in the same solution. The breakdown potential at which passivity broke down for 316L alloy was 0.00 m V, SCE, the corresponding value for 6% Mo alloy could not be reached up to the potential value of 700 m V, SCE. 316L alloy suffered extremely from crevice corrosion at 25° C, which indicates that the critical crevice corrosion temperature (below which crevice corrosion doesn't occur) was lower than test temperature. For 6% Mo alloy, the critical crevice corrosion temperature was higher than the testing temperature. Electrochemical parameters indicated that 6% Mo alloy exhibited higher crevice corrosion resistance than 316L alloy. Slow strain rate test technique (SSRT) has been employed to detect the susceptibility for stress corrosion cracking of conventional 316L austenitic stainless steel and 6% Mo super austenitic stainless steel alloys. Tensile testing was carried out in air and in 3% NaCl solution of pH 1.5 at open circuit potential and under controlled potentials. Tests were performed for both the un-welded (base-metal) and welded (weldment) conditions of both alloys. The changes in tensile properties as well as fractography of the fractured surfaces were used as a tool to describe the stress corrosion cracking susceptibility. 316L austenitic stainless steel base-metal and weldment as well as 6% Mo in the base-metal and weldment didn't show evidence for stress corrosion cracking on tensile testing in solution and under controlled potentials, however, a decrease in tensile properties was shown to occur in solution and under controlled potentials compared to tensile properties in air.

School

School of Sciences and Engineering

Department

Interdisciplinary Engineering Program

Date of Award

6-1-2003

Online Submission Date

1-1-2003

First Advisor

Hanadi G. Salem

Second Advisor

Magda Mohamed Amin

Committee Member 1

Abdel Wahab A. ElSayed

Committee Member 2

Maher Y.A. Younan

Committee Member 3

Amal K. Essawi

Document Type

Thesis

Extent

139 leaves

Library of Congress Subject Heading 1

Stainless steel.

Library of Congress Subject Heading 2

Corrosion resistant alloys.

Rights

The American University in Cairo grants authors of theses and dissertations a maximum embargo period of two years from the date of submission, upon request. After the embargo elapses, these documents are made available publicly. If you are the author of this thesis or dissertation, and would like to request an exceptional extension of the embargo period, please write to thesisadmin@aucegypt.edu

Call Number

Thesis 2003/38

Location

mgfth;mrs2

Download

Share

COinS