The effect of environment on mechanical properties of coated and uncoated alloys

High temperature materials selection is often based on review of databases of mechanical properties and environmental resistance.  However, for long-term applications, one concern is how environmental degradation may degrade the mechanical properties.  One example is internal oxidation of Ni-base superalloys in steam.  An additional aspect is the effect of oxidation-resistant coatings on the substrate mechanical properties.  Examples are given of the effect of environment on the mechanical properties of both Fe- and Ni-base alloys with and without coatings.