Abstract
The corrosion-fatigue properties of weathering steel in sea water were investigated with reference to its utility and efficiency as shipbuilding material. Repeated tension (in low-cycle ranges) and reversed bending (in low-and high-cycle ranges) tests were applied on weathering steel plates. In low-cycle fatigue, the frequency, of stress is respectively 10cpm for repeated tension and 7 or 30cpm for reversed bending. In the high-cycle, only for reversed bending it is 1500 or 2200cpm.
The results obtained are as follows:-
(1) In the low-cycle range, but little effect of corrosion is seen on the fatigue strength in repeated tension, but a little effect is observed in reversed bending.
(2) In the high-cycle range, there is remarkable influence of corrosion on fatigue of weathering steel, and there is no fatigue limit, such as seen in air. If the coefficient of corrosion-fatigue is defined as k=(NA-Ns)/NA×100(%), where NA and Ns are the number of reversals of stress to fracture in air and in sea water respectively, the smaller the applied stress is the larger the coefficient of corrosion-fatigue is.
(3) The fatigue strength in aqueous solution saturated with H2S was also examined.
