Post-fire low-cycle fatigue behavior of stainless-clad bimetallic steels

Abstract

Stainless-clad bimetallic steel has attracted increasing attention in structural applications due to its superior corrosion resistance and cost-effectiveness. However, its post-fire low-cycle fatigue behavior remains largely unexplored. This paper presents an experimental investigation into the post-fire low-cycle fatigue behavior of 316L + Q355 stainless-clad bimetallic steel, considered three key variables: nine target exposure temperatures (room temperature and 300 to 1000 °C in 100 °C increments), two cooling methods (air cooling and water cooling), and three strain amplitudes (1.0, 1.5, and 2.0 %). Fatigue failure modes, cyclic stress–strain responses, peak stress evolution, and fatigue life variations were systematically examined. The results indicate that air-cooled specimens exhibited fatigue life comparable to room-temperature conditions up to 500 °C, a moderate increase between 500 and 700 °C, and a reduction beyond 800 °C. For water-cooled specimens, fatigue life was similar to air-cooled counterparts below 700 °C but progressively decreased at higher temperatures. Based on the experimental results, temperature-dependent parameter expressions were developed for air-cooled and water-cooled specimens in both the adapted Basquin-Coffin-Manson and strain energy-based models, and validation demonstrated that the adapted Basquin-Coffin-Manson model achieved higher predictive accuracy over the entire temperature range.