STRESS CORROSION CRACKING OF Al-4% Cu ALLOY AGED WITH STRESSING.

The characteristics of an alloy aged with and without stressing were examined at the corrosion potential in 1 mol/kg-NaCl plus 0. 09 mol/kg-H//2O//2 solution, and at various potentials in 1 mol/kg-NaCl solution with reference to pitting potentials for grain boundaries determined without stressing. The specimens aged with stressing in the temperature range 130-210 degree C show lower susceptibility than those aged without stressing in 1 mol/kg-NaCl plus 0. 09 mol/kg-H//2O//2 solution. Fracture time of specimens aged at 180 degree C for 15 h decreased exponentially with increasing potential above V prime //C//G in 1 mol/kg-NaCl solution.