Annealed austenitic stainless steel plates are an attractive candidate material for cryogenic applications such as liquid hydrogen storage tanks. Thanks to their FCC crystal structure these steels remain ductile down to very low temperatures. Such stainless steels also possess other attractive properties such as good corrosion resistance. Nevertheless, austenitic stainless steels suffer from an intrinsically low yield strength which hampers their use as lightweight storage structures.

An attractive solution to improve strength is the use of thermomechanical controlled processing (TMCP), which has the potential to increase the yield strength significantly. However, very few studies exist on this technique applied to austenitic stainless steels and the effect of TMCP on low temperature toughness is not well studied for these materials.

The current contribution investigates the role of a TMCP treatment on the strength and toughness of different austenitic stainless steels. Large TMCP treated coupons have thus been produced by two-pass plain strain hot compression tests using a Gleeble ® HDS-V40. Additional reference coupons were also made following single pass compression tests. From such coupons the strengthening effect due to TMCP could be determined by room temperature tensile tests. The low temperature impact toughness at -196°C and -269°C was also evaluated by subsize Charpy tests. From the results obtained the role of alloy chemistry and TMCP on the realised strength could be determined. Moreover, Charpy impact tests allowed assessment of the alloys suitability for liquid hydrogen storage and the effect of TMCP on impact energy was also determined.