Incoloy 800, 800H, and 800HT are nickel-iron-chromium alloys with good  strength and excellent resistance to oxidation and carburization in  high-temperature exposure. These nickel steel alloys are identical except for  the higher level of carbon in alloy 800H, and the addition of up to 1.20 percent  aluminum and titanium in alloy 800HT. Incoloy 800 was the first of these alloys  and it was slightly modified into Incoloy 800H.