Supervisory materials engineer, Army Materials and Mechanics Research Center, Watertown, Mass.
Staff scientist, General Dynamics Corporation, San Diego, Calif.
Pages: 17 Published: Jan 1976
In this study both corrosion fatigue and stress-corrosion cracking behavior of a high-hardness laminar composite steel are examined in the presence of a 3.5 percent sodium chloride (NaCl) environment and compared to the behavior in air. It is shown that the susceptibility is not limited to specimens with a crack or notch. Smooth specimens with a machine ground surface tested under static as well as cyclic loading are affected adversely by the 3.5 percent NaCl environment. Using center notched panels to study crack growth behavior, it is shown that the influence of the 3.5 percent environment becomes more apparent as the maximum cyclic stress decreases. Ballistically damaged panels were also examined in a corrosive environment under the same cyclic stress conditions. Compared to the center notched panels a longer life is observed. It is suggested that this is due to the orientation of the ballistically induced cracks with respect to the loading axis. Environmental effects are also seen in the static loading of ballistically damaged panels. KIscc estimates were obtained from these panels and compared to the results of conventional specimens. Both sets of results indicate significant susceptibility of the laminar composite steel to stress corrosion.
laminates, composite materials, steels, stress corrosion, fatigue behavior, environmental effects
Paper ID: STP28682S