On Corrosion Fatigue Strength of High Tensile Steels

Abstract

Corrosion fatigue behaviors have been studied on low carbon steels and high tensile steels in 3%NaCl. The corrosion fatigue strength against the number of cycles was estimated by the following formula.
σ_ac=σ_a/(1+B·f^-p·N_f^p+q)
where σ_a is the fatigue strength tested in air, f is the cyclic speed, N_f is the fatigue life to failure, and B, p, q are the material constants.
It was obtained experimentally that the material constants were given as follows;
(1) For a plain specimen of SM41B steel and a notched specimen of HT 80 steel, B=2.14×10^-4, p=0.39, q=0.36 under plane bending corrosion fatigue tests.
(2) For a plain specimens of HT 80, HY 110, and HY 130 steels, B=4.78×10^-4, p=0.39, q=0.36 under plane bending corrosion fatigue tests.
(3) For a plain specimen of SM41B steel, B=1.08×10^-4, p=0.39, q=0.36 under tention and compression corrosion fatigue tests.
(4) The material constant B is given by the following function.
B=8.7×10^-4logσ_w-1.0×10^-3
where σ_w is the fatigue limit tested in air.