Skip to Main Content
Skip Nav Destination


The curved parts of exit pigtails made of wrought Incoloy 800H tubing used in steam reforming furnaces failed by performance after a period of service shorter than that predicted by the designers. Examination of a set of tubes consisting of both curved (perforated) and straight parts revealed that the cracks initiated at the outer surface by a combined mechanism of creep and intergranular embrittlement. A smaller grain size resulting from cold bending fabrication procedures for the curved parts was responsible for accelerating the embrittlement. It was recommended that hot bending be used for fabrication of the curved parts. A change of alloy to a low-alloy chromium-molybdenum allay to protect against heat was also suggested.

You do not currently have access to this chapter.
Don't already have an account? Register

Sergio N. Monteiro, High-Temperature Failure by Perforation of Incoloy 800H Pigtails in Reformer Furnaces, Handbook of Case Histories in Failure Analysis, Vol 1, Edited By Khlefa A. Esaklul, ASM International, 1992, p 354–357,

Download citation file:

Close Modal

or Create an Account

Close Modal
Close Modal