Mechanical behavior of sorbitic and austenitic steels in strongly hydrogenating environments: Relevant use prospects

Premature fracture tests were carried out on two different types of steel: AISI 9840 of sorbitic structure and AISI 304 stainless of austenitic structure. Quite a number of tests were made, varying both the pre-load and the discharge density of hydrogen. Examinations at SEM of the fracture surface were carried out. In this context many behavior differences in the alterations of the mechanical characteristics in the two materials tested were shown. It has been established through these tests that AISI 304 is the ideal material to be put in contact with hydrogen, provided the value of σ_0.2 in its walls is not exceeded.