Stress Corrosion Cracking of Austenitic Stainless Steels in Potentiostatically Controlled Chloride Environments at Ambient Temperature
No Thumbnail Available
Date
2015-11-04
Journal Title
Journal ISSN
Volume Title
Publisher
Universitatea Politehnica Timisoara (UPT), Romania
Abstract
In the earlier study carried out to assess the effect of applied potentials on stress corrosion cracking of Austenitic Stainless Steels (ASS), Type 304L in a potentiostatically controlled chloride environment at ambient temperature, the assessment of cracks in failed specimen was limited to optical microscope. In this present study, Scanning Electron Microscope (SEM) was used in addition to optical microscope to gain a better understanding of the Stress Corrosion Cracking (SCC) mechanism in the failed specimen. Stress corrosion cracking tests were carried out on annealed ASS using a Slow Strain Rate Test (SSRT) technique in sodium chloride solution acidified with hydrochloric acid at ambient temperature. Post-mortem assessments of failed specimens were carried out using both optical and SEM. The study showed that plastic elongation, ultimate tensile strength and time to failure decrease as the applied potential increases during the slow strain rate test. The study showed that immunity of ASS to chloride SCC was improved when the electrochemical potential was maintained in the primary passive potential range. Post-mortem assessment of failed specimens showed evidences of SCC and ductile failure on the fracture surface. The cross sectional analysis of the failed samples showed cracks that were predominantly transgranular stress corrosion cracks.
Description
Keywords
Failure, Passive film, Stress corrosion crack, Stainless Steels, SEM
Citation
Ahmed, I. I., Yahaya, T., Adebisi, J. A., Aremu, I. N., Alabi, A. G. F., & Lyon, S. B. (2015). Stress Corrosion Cracking of Austenitic Stainless Steels in Potentiostatically Controlled Chloride Environments at Ambient Temperature. Annals of the Faculty of Engineering Hunedoara - International Journal of Engineering, Vol. 13 (Issue 4), 151-158.