In-Fire and Postfire Mechanical Properties of Duplex Stainless Steel S22053

Abstract

Stainless steel has broad application prospects in building structures because of its favorable corrosion resistance and durability, attractive appearance, and easy conformity with architectural aesthetics. In order to evaluate in-fire and postfire structural behavior of stainless-steel structures, the in-fire and postfire mechanical properties of duplex stainless steel S22053, including elasticity modulus, nominal yield strength, ultimate strength, elongation after fracture, and microstructure, were obtained by 111 standard tests. Among them, the in-fire tests considered the effect of exposure temperature (ranging from 20°C to 700°C) on mechanical properties, and the postfire tests considered the effects of exposure temperature (20°C, 200°C, 400°C, 600°C, 800°C, and 1,000°C), high-temperature exposure duration (0.5, 3, 10, and 20 h), and cooling mode (air cooling and water cooling). Also, the test results were compared with ordinary carbon steel, high-strength structural steel, austenitic stainless steel, ferritic stainless steel, and European standards; and the characteristics of mechanical properties of S22053 are summarized. Predictive equations of the mechanical properties of in-fire and postfire S22053 are established by fitting to the test data with the least-squares method. The predicted results using the established equations are highly consistent with the experimental data. Thus, the equations can provide key data for residual mechanical property evaluation of stainless-steel structures.