Criterion for Qualification of Dissimilar Metal Welds for Service in Hydrogen Containing Environment

Reported/Well known failures of dissimilar metal welds (DMW) in upstream O&G

•8630 Low Alloy Steel-Alloy 625 Subsea kit
•Found to be hydrogen assisted cracking (HAC)
•Cathodic Protection subsea drives H+ evolution at surface (possible absorption where coating may not be present/failed)
•Led to development of delayed hydrogen cracking test (DHCT)
•Currently a qualitative method for ranking fitness for service of DMW combinations/PWHT parameters based on time to failure (TTF)

Industry Sponsor: TechnipFMC, Shell, Stress Engineering

Faculty: Boian Alexandrov (OSU)

Graduate Student: Will Siefert

Industry Contact: Jorge Penso, Pat Boster, Elliott Turbeville