For direct hydrogen contact and storage systems, mainly austenitic stainless steels of the group 316L are currently specified by international regulations as best practice based on its chemical, mechanical and metallurgical properties. During development phases, different challenges occurred regarding process, material couplings and designs as well as risks for different corrosion effects. Products like metallic tanks and H2 – Auxiliaries (seamless pipes, valves, manifolds) covering challenges regarding long term durability in real applications.

Supplier comparison and basic metallurgical studies have been done on material 316L grades with focus on mechanical properties and metallurgical effects. High number of segregations have been observed in this study using metallographic methods and SEM-EDX analysis. Influence of this metallurgical phases on joining / heat affected zone has been investigated using intergranular corrosion test method.

Stress corrosion test study was realized under different approaches on H2 – Auxiliaries to assess the impact of cold forming and internal stresses on the SCC sensitivity.

Keywords: Stainless steel 316L, Supplier comparison, segregations, heat affected zone (HAZ), intergranular corrosion, stress corrosion cracking (SCC).