Hydrogen Embrittlement Type Stress Corrosion Cracking Behavior of Wrought Magnesium Alloy AZ31

✍ Scribed by Yoshihiko Uematsu; Toshifumi Kakiuchi; Masaki Nakajima

• Publisher: Elsevier
• Year: 2011
• Tongue: English
• Weight: 877 KB
• Volume: 10
• Category: Article
• ISSN: 1877-7058
• DOI: 10.1016/j.proeng.2011.04.096

✦ Synopsis

Stress corrosion cracking (SCC) behavior of wrought magnesium alloy, AZ31, was investigated. SCC tests were performed using compact tension (CT) specimens in 3%NaCl solution under hydrogen charged conditions, where the cathodic potentials were -1.4, -2.5 and -3.0V. According to Pourbaix diagram, the cathodic potentials of -2.5 and -3.0V correspond to the immunity region. Under the immunity condition, hydrogen embrittlement (HE) type SCC occurred where the K Iscc value was much higher than that of active path corrosion (APC) type SCC. The K Iscc value decreased and the crack propagation rates, da/dt, increased with decreasing cathodic potential in the immunity region where HE type SCC occurred. At the cathodic potential of -3.0V, da/dt was insensitive to the stress intensity factor.