C2024-20319 Testing Heavily Cold Formed 22Cr Duplex Stainless Steel Exposed To Liquid Mercury To Assess Liquid Metal Embrittlement Susceptibility

William Kovacs, Bjorn-Andreas Hugaas, Kristian Eriksen, Stian Hauger - Existing literature suggests that while 22Cr may not be generally susceptible to Liquid Metal Embrittlement (LME) when exposed to mercury[1],[2],[3], heavily cold formed 22Cr materials may be susceptible[4].The LME susceptibility of cold formed UNS S31803 was tested using four-point bend, slow strain rate, and interrupted slow strain rate techniques; simulating a range of strains from primarily elastic deformation of as-produced / as-welded pipe to high plastic deformation of cold formed pipe. Specimens were selected from the base metal, the weld metal / heat affected zone (HAZ), and from pre-strained material simulating cold forming. The testing was conducted in the presence of mercury (only) at both ambient temperature and 40 °C. The passive film was intentionally disrupted by scratching at the initiation of the tests. The results of this testing did not indicate evidence of LME for any of the material / env