Experimental study on the mechanical properties of high-strength stainless steel at room and elevated temperatures

Abstract

Tensile tests at room and elevated temperatures were conducted on a novel high-strength stainless steel to study its mechanical properties at different temperatures. The failure modes, stress–strain curves and strain–temperature curves for all the coupons were obtained and investigated. The tests at room temperature show that the stress–strain curves at room temperature do not include an obvious yield plateau and agree well with the constitutive model proposed by Gardner. The test results at elevated temperatures show that when the temperature is less than or equal to 200 °C and greater than or equal to 400 °C, the strength and initial stiffness of this novel material decreased gradually with increasing temperature, Whereas its strength did not change significantly at temperatures of 200∼400 °C. Based on the test results, a constitutive model and corresponding hardening index for elevated temperatures were deducted, and the reduction factors of mechanical parameters at elevated temperatures were proposed. In addition, a reliability analysis of these mechanical parameters was conducted, and then the standard values of the material strength and the statistical parameters of the material properties uncertainties for this type of high-strength stainless steel were presented.