Oil refinery hydrotreating and hydrodesulfurization are high temperature processes which can cause sensitization and/or reduced ductility in some materials of construction, while the presence of sulfur and other impurities in these processes can lead to various corrosion mechanisms. Alloy 825 (UNS N08825) is often used in this demanding application. The effects of long term elevated temperature exposure and welding on the mechanical properties, microstructure and corrosion resistance of this nickel base alloy have been investigated.
Keywords: hydrotreating, hydrodesulfurization, petrochemical, corrosion, sensitization, stress corrosion cracking, chlorides, polythionic acid, aging, alloy 825(UNS N08825), alloy 304(UNS S30400), alloy 321(UNS S32100), alloy 800(uNS N08800), 9Cr-1Mo Steel(UNS K90941), 5Cr-0.5Mo Steel(UNS K41545), 1020 Carbon Steel(UNS G10200)