Effect of artificial aging on tensile properties and resistance to corrosion of 24S-T aluminum alloy

Abstract

The effect of aging commercial 24S-T aluminum alloy sheet, [or various periods at 350°, 3 75°, 385° and 400° F, on its t e ns ile properties and resis tance to corrosion was determined. Aging for 3 hours at 385 0 F prod uced an increase in yicld strength of about 25 percent above an in itial valuc of about 50,000 Ib/ in . 2 , an increase in te nsile s tre ngt h of about 3 percent above an initi al valuc of 70,000 Ib/in.2, and a decrease to about onc-third of the initial elongation of 17 to 18 perce n t. Approximately t hc samc values for thcse propertie were obtained by agi ng the material for 20 hours at 350 0 F, 5 hours a t 375° F , or 1% hours at 400 0 F. Mate rials aged 3 to 10 hours at 3 5° F and 6 to 12 hours at 375 0 F were generally immune to s tre s-corrosion cracking and were no more severcly damaged in corrosive media, J a CI + H20 2 solu tion or marine atmo phere, t han the com mcrcially heat-tr eated material exposed without artificial aging.