Alloy 803 is used in the chemical process industry for its high temperature strength and corrosion resistance. Knowledge of the microstructural characteristics as a fimction of time and temperature are essential for accurate rationalization of mechanical property performance under actual service conditions. This paper seeks to determine the microstructure of alloy 803 as a function of time and temperature for times up to 34,000 hours and temperatures ranging from 595°C to 1095”C. Post-exposure room temperature tensile data are also presented as an indication of the alloy’s tolerance to downtime strains. Intermediate temperature mechanical strength can be attributed primarily to gamma prime (y’) and higher temperature strength to M23C6content.
Keywords: alloy 803, creep rote, stress rupture, tensile strength, microstructure, gamma prime, carbides, long term exposure