A short-crack growth model for corrosion-fatigue propagation in a mild steel exposed to artificial rainwater

One of the main problems for railway maintenance is the correct estimation of a safe service life for axles exposed to corrosion, since on one side there is no precise indications in existing standards while, on the other side, there is the very good experience of belgian railways of avoiding axle painting. In this paper we examine the applicability of some crack growth models for analysisng a data set of corrosion-fatigue crack growth data previously obtained onto the A1N railway axle steel under exposition to artificial rainwater. It will be shown that a fairly simple crack growth model could be easily estimated as a ’back-calculation’ from the S-N diagram. Application of the model to prediction of nucleation of ’technical crack’ under service load spectra will be also discussed.