TRACK: Materials for Harsh Environments
As the primary source for bulk hydrogen production worldwide, steam methane reformers (SMRs) require heat resistant materials to withstand their challenging continuous operating conditions that exceed 815°C. Good high temperature creep performance is a requirement for materials used in such conditions and HP-modified, HP-microalloyed grades of Ni-based alloys are commercially employed for such applications. However, prolonged exposure to high temperatures promotes changes to the metastable microstructure of these alloys and an understanding of the effects of such transformations on long-term creep performance of these alloys is lacking. Ongoing research at EPRI aims to develop an integrated approach for the life-management of components made from these alloys. As a part of this effort, a structured investigation involving laboratory heat treatment studies and relevant creep testing of laboratory-aged samples have been performed to determine the microstructural transformations that occur during service in SMR components and understand the association of such microstructure changes to the evolution of creep damage in this alloy.