Aging Response on the Stress Corrosion Cracking Behavior of Wrought Precipitation Hardened Magnesium Alloy
Abstract
Constant immersion testing and slow strain rate testing (SSRT) are conducted on WE43 wrought magnesium alloy in a 3.5 wt.% NaCl solution. After solution annealing at 525°C for 8 h, the alloy was isothermally aged at 210°C for 15 h, 48 h, and 144 h to obtain under-aged (UA), peak-aged (PA), and over-aged (OA) microstructures, respectively. The solution annealed (SA) microstructure had the lowest weight loss (~0.10 mg.cm-2 day-1) and UA microstructure the highest weight loss (~0.20 mg.cm-2 day-1) corrosion rates after 32 days of exposure in chloride solution. A Y = kt⅟2 type relationship was observed for WE43 microstructures, where Y is the corrosion rate parameter, t is the duration of exposure in days and k is a rate constant. SSRT was carried out at an initial strain rate of 10-6 s-1 in air and 3.5 wt.% NaCl solution to investigate stress corrosion cracking (SCC) susceptibility. SCC susceptibility index was in the order PA > UA > SA > OA. Intergranular failure morphology on the fractured surface after SSRT in chloride solution can be attributed to micro-galvanic activity between grain boundary second phase and adjacent regions. Comparison of electrochemical measurements in unstressed and stressed conditions indicated two orders of magnitude difference in electrochemical resistance of the alloy.
Recommended Citation
G. R. Argade et al., "Aging Response on the Stress Corrosion Cracking Behavior of Wrought Precipitation Hardened Magnesium Alloy," Journal of Corrosion Science and Engineering, vol. 21, University of Manchester, Jan 2018.
Department(s)
Materials Science and Engineering
Keywords and Phrases
Constant immersion testing; Heat treatment; Magnesium; Scanning electron microscopy; Stress corrosion cracking
International Standard Serial Number (ISSN)
1466-8858
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2024 University of Manchester, All rights reserved.
Publication Date
01 Jan 2018