Fabrication and Testing of Electron Beam Welded Alloy AA2219 Aluminum Pressure Vessels for High-Pressure Hydrogen Service

Abstract

Aluminum alloys offer significant advantages for hydrogen service such as low weight, improved uniformity of properties relative to forged austenitic stainless steels, and immunity to embrittlement in the presence of dry hydrogen. For these reasons aluminum alloys are now being considered for high-pressure hydrogen isotope pressure vessel applications where forged stainless steels have been the standard materials of construction for decades. In particular, alloy AA2219 is being evaluated due to its excellent weldability, microstructural stability, and good mechanical and fracture toughness properties. Prototype AA2219 pressure vessels have been fabricated and tested, including electron beam weld development, weld hardness and tensile testing prior to and after post-weld heat treatment, and burst testing. The design, manufacture, and testing of AA2219 pressure vessels will be discussed, including an ongoing long-term shelf storage program where pressure vessels are loaded with gaseous hydrogen at pressure of 103 MPa (85% of the burst pressure for these vessels).