| 摘要 |
A method is provided for improving the microstructure of nickel and iron-based precipitation strengthened superalloys used in high temperature applications by increasing the frequency of "special", low- SIGMA CSL grain boundaries to levels in excess of 50%. Processing entails applying specific thermomechanical processing sequences to precipitation hardenable alloys comprising a series of cold deformation and recrystallization-annealing steps performed within specific limits of deformation, temperature, and annealing time. Materials produced by this process exhibit significantly improved resistance to high temperature degradation (eg. creep, hot corrosion, etc.), enhanced weldability, and high cycle fatigue resistance. |
