Characterization of Hydrogen Diffusion in Offshore Steel S420G2+M Multi-layer Submerged Arc Welded Joint

Abstract As onshore installation capacity is limited, the increase in number of offshore wind turbines (OWT) a major goal. In that connection, OWTs continuously size and weight demand adequate foundations concepts like monopiles or tripods. These components are typically manufactured from welded mild steel plates with thickness up to 200 mm. The predominant welding technique submerged arc (SAW). accordance standards, occurrence hydrogen-assisted cracking anticipated by either minimum waiting time (MWT, before non-destructive testing joint allowed) at ambient hydrogen removal heat treatment (HRHT) elevated temperatures. effectiveness both can be estimated calculation diffusion time, i.e., coefficients. this study, these coefficients obtained for first thick-walled S420G2+M grade its multi-layer SAW joint. electrochemical permeation temperature used determination base material weld metal. within range 10 −5 −4 mm 2 /s (whereas metal had lowest) an analytical numerical related MWT. results showed long MWT occur, which would necessary significantly decrease concentration. Weld temperatures were calculated desorption experiments carrier gas hot extraction. They −3 characterization HRHT dwell-time. shows same tendency times also That means strongly influenced considered plate estimation any MWT/HRHT via should critically discussed.