Technical Note: Analysis of Stress Corrosion Testing of 2014-T651 Aluminum, Using Weibull Techniques Available to Purchase

This report analyzes the results of alternate immersion testing of samples of Type 2014-T651 aluminum in a 3.5% NaCl bath under 10 ksi tensile stress, during approximately one month of continuous testing to determine the distribution of the times until the noticeable appearance of stress corrosion cracking (SCC). Weibull distributions were used because a wide range of failure phenomena could be covered. Five different groupings or broad categories of 2014-T651 aluminum specimens from three different manufacturers were used based upon the source (manufacturer), the specification to which the sheets were prepared, and the method of preparation. A wide variation of results occurred from one grouping to another. Characteristic lifetimes were as low as 70 hours and as high as 1085 hours. Both increasing failure rate phenomena, such as early failure of all specimens in a group, and decreasing failure rates were exhibited.