|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Environmentally Assisted Cracking: Theory and Practice
||Strain Rate Effects on the Stress Corrosion Cracking Behavior of Ni and Co Based Superalloys for Marine Applications
||Allison Popernack, James Burns
|On-Site Speaker (Planned)
The effect of strain rate on stress corrosion cracking (SCC) susceptibility is poorly understood for fracture mechanics based characterization, thus yielding an incomplete view of possible crack growth behavior experienced in service. This study aims to quantify the effect of applied stress intensity rate on the measured crack growth rate (da/dt) in Co- (MP98t) and Ni-based (Monel K-500) superalloys, known to be susceptible to H-embrittlement. Slow-rising stress intensity testing conducted under cathodic polarization in NaCl solution using real-time crack growth measurements, via direct current potential difference (DCPD), establishes the effect of strain rate on SCC behavior. Results demonstrate a clear increase in Stage II crack growth rate (da/dt<SUB>II</SUB>) for both materials as the applied strain rate increased. Monel K-500 exhibits distinct upper and lower da/dt<SUB>II</SUB> bounds. These data provide mechanistic understanding and inform the protocol necessary for accurate, conservative fracture mechanics based characterization of SCC susceptibility.
||Planned: Supplemental Proceedings volume