Influence of carburisation on the ductility of four high temperature alloys

The influence of carburisation and thermal exposure on the room temperature ductility of Alloy 800 H, Inconel 617, Hastelloy X and Nimonic 86 has been investigated. It was found that carburisation affects the ductility of Alloy 800 H much less severely than that of the nickel-base alloys. This is explained in terms of the varying volume fractions of carbide formed for a particular carbon content as the result of, first, different carbon solubilities in the iron and nickel-base materials and, second, the formation of carbides with different metal: carbon stoichiometry ratios. (author)