Crack Tip Plasticity Associated with Corrosion Assisted Fatigue.
Interim rept. Jun 75-Jun 76,
SOUTHWEST RESEARCH INST SAN ANTONIO TEX
Pagination or Media Count:
Water vapor has been found to change the plasticity associated with fatigue crack propagation in an 0.05 wt. carbon steel. Dislocation subcell size is increased, the extent of subcell formation decreased, and crack tip opening displacements decreased by the addition of water vapor to the testing environment. Fracture surface features are also altered by environment, consistent with the plasticity observations. Preliminary results for the aluminum alloy 6061-T6 indicate a somewhat different material response, yet to be clarified. The steel results are consistent with a strengthening of the material, or a decrease in material ductility, or both, within the cyclic plastic zone of the propagating fatigue crack.
- Properties of Metals and Alloys