Abstract
The mechanism of flow‐enhanced diffusion transport of solute in corrosion fatigue cracks was analyzed theoretically, and the value of the effective diffusion coefficient 
of a solute in narrow cracks was determined experimentally as a function of a dimensionless group of parameters using an artificial model crack. pH values, resulting from polarization of parts of the crack walls made of pipeline steel, were measured near the crack tip during fatigue cycling in aerated 3.5%
solutions. The rate of transport of hydroxyl ions from the crack mouth to the tip can be accounted for on the basis of an average value of 
in the crack, which is more than three orders of magnitude larger than the normal solute diffusion coefficient 
.