Analysis of Al-alloy billets of specification AMS4101 2124 T851

2124 T851 billets were received in corroded condition. Examination revealed corrosion on all the billets. The extent of corrosion was found to vary from billet to billet. Metallurgical analysis of a randomly selected sample from one of the billets showed pitting corrosion in the affected regions. The depth of the pits in this sample was measured to be in the range 200 to 1000 m. The corrosion pits were associated with intergranular branching cracks. Subsequent examination revealed more severe corrosion in some of the billets. However, no scientific approach could be adopted to estimate as to what could be the maximum depth of the corrosion layer in the billets so that any possible salvage mechanism could be thought of. In view of this, it is concluded that the billets in the present condition are not suitable for any aeronautical applications and hence they need to be rejected