In a study by Proctor et al. a strength reduction was observed due to surface damaging in humid air at high temperatures. The strength tests on these damaged specimens were carried out in normal lab atmosphere. Unfortunately, these tests are affected by subcritical crack growth.
In the present report we show on the strength results obtained in humid air, in which way these data can be used to determine the inert strength of the damaged surface.
Proctor et al. provided images of the surface defects and identified, localized corrosion centers. In our report we show how the effects of these local corrosion defects can be handled fracture mechanically.