A normalization of corrosion fatigue behaviour: an example using an offshore structural steel in chloride environments

A normalized presentation of the metal fatigue process is proposed and appl ied to the corrosion fatigue behaviour of an offshore structural steel unde r different loading conditions. Corrosion fatigue development in this steel under different stress levels and frequencies is presented in both 'normal ' and 'normalized' terms. Experimental results on pitting and corrosion fat igue-crack growth are used to introduce the new normalized presentation app roach, which may be employed to illustrate the corrosion fatigue behaviour of any given metal/environment system. This allows a description of the ini tiation and growth of defects to be made, involving both time-dependent and cycle-dependent stages. It is suggested that a set of dependencies between fatigue-characterizing parameters may be presented in graphic form and use d as a 'fatigue certificate' for any given metal/environment system.