1975 年 24 巻 261 号 p. 540-544
Though some investigations have been done to clarify the corrosion fatigue strength of steels, there is few investigation ever made on their corrosion fatigue damage.
In this paper some results of the corrosion fatigue test and the measurement of electropotentials are described to discuss the corrosion fatigue damage of 0.82%C piano wire.
From the results, the following conclusions were obtained;
(1) Piano wire of 0.82%C is heavily damaged within the first 20% of the total life.
(2) The progress of the damage under the corrosion fatigue process is devided into three stages; the first stage is the formation of corrosion pits, the second stage is the progression of some pits into cracks, and the third is a stage in which one of the crack propagates causing the specimen to break.
(3) The number of cycles at which the electrode-potential reaches its maximum value, shows the end of the first stage.
(4) The relation among the stress amplitude σ, the number of cycles to failure N and the number of cycles at maximum electrode-potential Np is as follows.