Heavy-wall Cr-Mo pressure vessels, such as hydroprocessing reactors, are subject to embrittlement from both microstructural transformations and their high pressure, high temperature hydrogen environment. Understanding the effects of the embrittlement on fracture properties is crucial for developing Minimum Pressurization Temperature curves that are both safe and not overly restrictive. The focus of this project is to determine the effect of the hydrogen atmosphere, termed “hydrogen environment assisted cracking (HEAC)” on the fracture toughness of 2.25Cr-1Mo and the 22V alloys. Initial work has shown an apparent effect on 1.25Cr-0.5Mo steels in specimens with minimal dissolved H2, but very little research has been done on the 2.25Cr-1Mo and 22V alloys.
Member input Metals PDC July 2026