|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Environmentally Assisted Cracking: Theory and Practice
||An Investigation of Stress Corrosion Cracking Performance for Naturally Aged 5xxx Alloys
||William Golumbfskie, Matthew McMahon, Emily Holcombe, Mitra Taheri
|On-Site Speaker (Planned)
Marine Grade (5xxx) aluminum alloys are considered sensitized when magnesium precipitates out of solution forming a deleterious β-phase (Mg2Al3) along the grain boundaries, rendering them susceptible to stress corrosion cracking (SCC). The extent and rate of sensitization is dictated by exposure to elevated temperatures. Current research uses accelerated heat treatments in laboratory settings to simulate sensitization occurring naturally at lower temperatures and longer times.
This study will evaluate material performance of thin plate naturally aged 5xxx aluminum compared against laboratory aged specimens. Slow rising stress intensity testing is used to quantify the effect of sensitization on IG-SCC susceptibility, identifying differences in threshold stress intensity in potentiostatic conditions and full seawater immersion. The microstructure and extent of sensitization will be characterized using microscopy coupled with electron backscatter diffraction (EBSD) and sensitization testing. This study will evaluate naturally aged and lab aged specimens, providing insight for microstructures with increased resistance to SCC.