Abstract
The effect of stress waveforms on corrosin fatigue and the role of dissolution mechanism in 3NilCr steel and 20Ni maraging steel have been investigated in aerated 3% NaCl solution and synthetic seawater under sinusoidal, triangular, square, positive sawtooth, negative sawtooth, and trapezoidal stress waveforms with open circuit at frequency of 1Hz and stress ratio of 0.1. The crack growth rates under square waveform were substantially lower than under sinusoidal and triangular waveforms, but the crack growth rates under sinusoidal waveform were slightly higher under triangular waveform. For a given frequency the growth rates under the positive sawtooth waveform are higher than those under the negative sawtooth waveform. The fatigue crack growth rates of most specimens were in good agreement with the values calculated by the model based on the dissoultion mechanism.
