Thermal stability is an important design characteristic for engineering materials used at elevated temperatures. It may be defined as the resistance of an alloy to degradation of ductility and toughness when subjected to long-term thermal exposure. One common measurement of thermal stability is residual room temperature tensile elongation following such exposure. The following are test results for both plate and sheet materials exposed for 6,000 to 8,000 hours at different temperatures. Data are averages of at least two tests.
* Data for 6,000 hour exposures are indicated with an asterisk
Another common measurement of thermal stability is residual room temperature impact strength following long-term exposure at elevated temperatures. The following are results for impact tests performed upon samples exposed for 5,000 to 10,000 hours at different temperatures. The comparison includes values derived from multiple in-house tests and values taken from published data. Results are for Charpy V-Notch tests unless otherwise noted.
* Charpy Key Hole tests are indicated with an asterisk. All others are Charpy V-Notch tests.
(1) 5,000 Hour Exposure at 1292°F (700°C)
(2) 5,000 Hour Exposure at 1472°F (800°C)
(3) 10,000 Hour Exposures