한국재료학회지 제28권 제12호 (p.738-747)

항공용 고강도 2xxx계 알루미늄 합금의 3.5 % 염수 환경에서의 응력부식균열 민감도

Stress Corrosion Cracking Sensitivity of High-Strength 2xxx Series Aluminum Alloys in 3.5 % NaCl Solution
키워드 :
stress corrosion cracking,2xxx series aluminum alloy,3.5% NaCl solution

목차

Abstract
1. 서 론
2. 실험 방법
3. 결과 및 고찰
4. 결 론
References

초록

For the aerospace structural application of high-strength 2xxx series aluminum alloys, stress corrosion cracking(SCC) behavior in aggressive environments needs to be well understood. In this study, the SCC sensitivities of 2024- T62, 2124-T851 and 2050-T84 alloys in a 3.5% NaCl solution are measured using a constant load testing method without polarization and a slow strain rate test(SSRT) method at a strain rate of 10-6 /sec under a cathodic applied potential. When the specimens are exposed to a 3.5% NaCl solution under a constant load for 10 days, the decrease in tensile ductility is negligible for 2124-T851 and 2050-T84 specimens, proving that T8 heat treatment is beneficial in improving the SCC resistance of 2xxx series aluminum alloys. The specimens are also susceptible to SCC in a hydrogen-generating environment at a slow strain rate of 10−6/sec in a 3.5% NaCl solution under a cathodic applied potential. Regardless of the test method, low impurity 2124-T851 and high Cu/Mg ratio 2050-T84 alloys are found to have relatively lower SCC sensitivity than 2024-T62. The SCC behavior of 2xxx series aluminum alloys in the 3.5% NaCl solution is discussed based on fractographic and micrographic observations.