| Popis: |
Publisher Summary The upper temperatures of heat cycles used in energy generation are limited by mechanical properties and resistance to attack by the ambient atmosphere. Although oxidation forms a passivating surface layer, solid particles in the hot gases can cause extensive damage by erosive action, which compromises the existence of a passive scale. Erosion–corrosion reactions are normally followed by measuring the weight change of the specimen as a function of time. The data must be interpreted with some caution due to erodent retention, particularly if the particles penetrated the metal surface. Studies of the erosion–corrosion of commercial alloys provide results for comparing alloy behavior, but it is more difficult to provide a detailed mechanistic interpretation of their behavior. The understanding about all erosion–corrosion mechanisms lies in a description of the way in which an erosive particle impact affects the surface oxide and surface layers of the metal. Under erosion, the lateral advance of the protective oxides is restricted and the surface is held in a state of extended transient oxidation in which all of the oxides that form are removed by erosion. |
