Cross-sectional behaviour of QN1803 high-strength stainless steel I-section stub columns in fire

QN1803 is a novel high-strength stainless steel with low nickel. Compared to traditional stainless steel, QN1803 high-strength stainless steel has higher yield strength and lower cost without compromising anti-corrosion properties, thus leading to a wide application prospect. This paper focuses on the cross-sectional behaviour of QN1803 high-strength stainless steel I-section stub columns in fire. A total of eight stub column tests were finished, of which six were elevated temperature tests and two were room temperature control tests. Room temperature and elevated temperature tensile coupon tests were conducted to obtain the material properties of the QN1803 high-strength stainless steel. The design methods of European fire design standard EN 1993-1-2 and the latest fire design methods proposed by Xing et al., which will be incorporated into the upcoming version of EN 1993-1-2, were evaluated in terms of accuracy and safety for the fire design of QN1803 high-strength stainless steel I-section stub columns. It was found that most ultimate cross-sectional resistances of QN1803 high-strength stainless steel I-section stub columns predicted by the design rules of European fire design standard EN 1993-1-2 were unsafe, while the ultimate cross-sectional resistances predicted by the design methods of Xing et al. were safe and accurate for the tested QN1803 high-strength stainless steel I-section stub columns.