Effect of thermal aging on microstructural and mechanical properties of Hastelloy C and C276

Hastelloy C and Hastelloy C276 are Ni-based alloys commonly used in applications where corrosion resistance and high temperature performance are required. The alloys are similar in composition, with Hastelloy C276 having a lower impurity content, making it more attractive for welding applications through avoidance of sensitization. The current effort focused on effects of low to moderate temperature (200-600˚C), short duration (100-1000 hours) thermal aging of the Hastelloy C alloy and low temperature (200-400˚ C), longer duration (decades long) aging of Hastelloy C276. Quasi-static mechanical characterization results are reported according to aging condition at room and elevated temperatures. Mechanical properties are correlated to lattice ordering reactions and precipitate evolution, with attention to the compositional differences between Hastelloy C and C276.

Sandia National Laboratories is a multimission Laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.