Stress-strain model of austenitic stainless steel after exposure to elevated temperatures

With the increasing use of stainless steel in structures, there is a research need to evaluate the post-fire behaviour of this structural material. An experimental research was conducted to investigate the mechanical properties of austenitic stainless steel of grade 1.4301 after heating and cooling down to room temperature. Three types of stainless steel coupons were tested, including flat and corner coupons cut from a square hollow section and curved coupons extracted from a circular hollow section. The post-fire stress-strain curves of stainless steel exposed to various temperatures (200-1000 °C) and heat soak times (0-135 min) were measured. The influence of different parameters on the elastic modulus, yield strength, ultimate strength and ultimate strain is discussed in this paper. Based on the test results, a stress-strain model is proposed for austenitic stainless steel after exposure to fire.