The Effect of Mean Stress on Corrosion Fatigue Life

An experimental investigation of the effect of mean stress on the fatigue life and corrosion fatigue life of cylindrical specimens is presented. Force controlled constant amplitude axial fatigue tests in the regime of 105 to 107 cycles were conducted for two different environments: in air (without corrosion) and in-situ in a corrosive environment, 0.824% NaCl aqueous solution flow. The test results are assessed with respect to various standard models of mean stress influence on fatigue. The reduction in material fatigue strength due to the corrosion environment is evaluated and the results obtained show that in a low salinity aqueous corrosive solution, the fatigue strength at 4x106 is reduced of a factor of 2 compared to no corrosion tests.