Determination of Stress Corrosion Cracking Resistance of Al-Cu-Mg Alloys by Slow Strain Rate and Alternate Immersion Testing

Increased artificial aging from the T351 temper to T851 temper is known to increase resistance to stress corrosion cracking (SCC) for Al-Cu-Mg alloy 2124. A series of incrementally aged 2124 alloy plate was tested for resistance to SCC by the slow strain rate technique and by the conventional alternate immersion test method. It is shown that slow strain rate test results are in agreement with the conventional test results. Using fracture energy and other loss in ductility parameters to denote resistance to SCC, it has been shown that this technique can be used as a more accurate SCC test. SEM examinations of fracture surfaces confirm the SCC indices obtained by the slow strain rate test.