Investigation of the effect of operating conditions on the mechanical properties of metals

Metal parts in service are found to undergo changes in mechanical properties under the influence of an aggressive environment acting at different temperatures, pressures, and motion rates. Under operating conditions, the environment usually degrades the long-term static and dynamic strength of materials. Crack initiation and growth occurs by corrosional, erosional, and cavitational action of the environment, whereas the adsorptive action of the medium contributes mainly to crack growth. The effect of strain rate on metal plasticity and creep at different temperatures is discussed. Fatigue testing with prescribed feed of the corrosive medium and programmed loading is examined.