Incoloy 800H pipe fittings elbows for extreme temperature and high pressure applications
The principle di?erence between alloys 800H and 800HT is the restricted aluminum and titanium content in 800HT, which results in higher creep and stress rupture properties.
Both alloy 800H and 800HT are generally considered to be superior to the base alloy 800 (UNS N08800) because of greater creep and stress rupture properties. Alloy 800H limits the C wt% from just 0.1% max in base alloy 800 to a 0.5% to 0.1% range. Alloy 800HT further controls this by limiting the C wt% to 0.6% to 0.1%. There are also limitations on the grain size for alloy 800 H/HT that are not in place for alloy 800. While Incoloy 800 is usually annealed at at approximately 1800¡ãF [980¡ãC], Incoloy 800H should be annealed at approximately 2100¡ãF [1150¡ãC].