Toughness Testing for Liquid Hydrogen And Helium Temperatures - Validation of Austenitic Stainless Steels for 4K (-452F) Use

This presentation is an Existing Code Requirement: Charpy impact test at a temperature no higher than the design minimum temperature. The Current Practice: is not clear, the indications are that testing is sometimes performed at -320F (liquid nitrogen or "LN2") for that and all lower temperatures. In some cases testing is probably not performed and CGA indicated successful operation of systems at -453F without required test. The Ballot activity: C&S Connect Record 13-341, Ballot 13-1746, initially proposed Charpy testing (lateral expansion criteria) at -320F to validate use at -425 (liquid helium or "LHe"). and PTCS Proposal..