Hydrogen embrittlement in the SAW and SMAW weld metal is investigated in this work by employing slow strain rate tensile (SSRT) tests and using a scanning electron microscope (SEM) to verify the fracture surface failure mode. Also, a comparison between the welded joints produced by both welding processes with the SUS316L base plate is made after the tests at −75 °C under three different test pressures and at −40 °C. The loss of ductility and reduction of strengths were observed for both welded metals but in different proportions and it is related to each microstructure produced after welding.
In a huge cryogenic storage tank manufacturing, the selection of the welding process is an important activity for the project. Both Submerged Arc Welding (SAW) and Shielded Metal Arc Welding (SMAW) are viable processes for stainless steel welding, each with its own strengths and considerations. SAW offers high deposition rates and deep penetration, making it suitable for thick stainless steel sections, but welding position and plate thickness are examples of limiting factors. On the other hand, SMAW, also known as stick welding, is versatile, portable, and can be used in various positions, making it suitable for both thin and thick stainless steel, although it typically has lower deposition rates compared to SAW. Furthermore, while SAW requires a controlled environment due to its submerged nature, SMAW is preferable for outdoor or challenging environments, which induce situations with difficult control of surface contamination and wind conditions.
For a cryogenic hydrogen storage tank, SUS316L is one promising candidate that has been studied by many researchers, (Herms et al., 1999; Michler et al., 2009, 2015; Michler & Naumann, 2008; San Marchi et al., 2008). Although this steel is said to have a good hydrogen embrittlement resistance, the deterioration can occur at low temperatures, for example between −50 to −80 °C (Álvarez et al., 2023; Freire et al., 2023; Fukuyama et al., 2003; Park et al., 2023). It was found that this embrittlement phenomenon may have a relationship with strain-induced martensite, the deformation by cross slip, and a decrease in stacking fault energy (SFE).
