Experimental study of the mechanical properties of a new duplex stainless steel exposed to elevated temperatures

Abstract

A new duplex stainless steel (S32001) with good corrosion resistance and mechanical properties has been introduced into building structures in recent years. It is necessary to study its mechanical properties at room temperature and high temperature to provide a reference for structural design. In the present research, a series of tensile tests were conducted in 11 groups at different temperatures, including room temperature and between 100 and 1000 °C. The steady-state tensile test method with strain rate control was adopted. The failure modes, stress-strain relationships, and the related mechanical parameters (including ultimate elongation, elastic modulus, yield strength, and ultimate strength) were investigated. The test results were compared with existing research finding related to the high-temperature mechanical properties of carbon and other stainless steels. The results indicated that: (1) the ultimate strain of S32001 is about 40% at room temperature, and the ultimate strain first decreases slowly and then increases rapidly with rising temperature. (2) When the temperature is below 500 °C, the elastic modulus of S32001 decreases slowly with the increase of temperature. When the temperature exceeds 500 °C, the elastic modulus decreases sharply with the increase of temperature. (3) The strength of S32001 decreases with increasing temperature. It decreases slowly when the temperature is lower than 500 °C and decreases faster when the temperature exceeds 500 °C. (4) Compared with the existing research results on the thermo-mechanical properties of other steel grades, significant differences between different steel grades can be found.

Keywords

• Duplex stainless steel
• Tensile test
• Elevated temperature
• Mechanical property
• Fire safety