Constitutive model of austenitic high-strength A4L-80 bolts at elevated temperatures

In recent years, the use of austenitic bolts in building structures increased rapidly. It is important to conduct the fire-resistant design of austenitic bolts because their mechanical properties may deteriorate faster than normal high-strength steel bolts in a fire. Therefore, the mechanical properties of the austenitic bolts at elevated temperatures should be clarified to provide a basis for structural fire design. In this paper, an experimental study was conducted to investigate the mechanical properties of A4L-80 stainless steel bolts at elevated temperatures ranging from 20 to 900 °C. Stress-strain curves and mechanical property index were obtained by the tensile tests. The test results were compared with other types of austenitic bolts and base materials at elevated temperatures, and a constitutive model of A4L-80 stainless steel bolts was proposed. It was seen that the proposed reduction factors can effectively predict the mechanical property of A4L-80 at elevated temperatures; the constitutive model was consistent with stress-strain curves obtained from tests.