Elevated temperature material behaviour and testing of novel, cost-efficient and high-performance stainless steel grades

Owing to their varying alloy contents, different stainless steel grades exhibit distinct material behaviour at elevated temperatures, which is also significantly different relative to the elevated temperature material response of carbon steel. This paper presents an experimental investigation into the elevated temperature material behaviour of one novel, nickel-free and cost-efficient austenitic and three high-performance austenitic, duplex and ferritic stainless steel grades, whose elevated temperature material behaviour is currently largely unknown. Both steady-state and transient-state tensile tests are carried out up to 1100 °C on the considered stainless steel grades, which are grade 1.4547 super austenitic stainless steel, grade 1.4678 nickel-free austenitic stainless steel, grade 1.4410 super duplex stainless steel and grade 1.4622 ferritic stainless steel. The material behaviour and properties of the considered stainless steel grades at various elevated temperature levels are experimentally determined. The elevated temperature material property reduction factors obtained from the tests are also compared against those recommended in the upcoming version of the European structural steel fire design standard EN 1993-1-2 for different groups of stainless steel grades. Finally, the ability of a two-stage Ramberg-Osgood material model to capture the elevated temperature stress-strain response of the considered stainless steels is demonstrated. It is envisaged that the findings of this study provide essential benchmark data for the fire design of stainless steel structures made up of the considered novel, cost-efficient and high-performance stainless steel grades.