Mechanical Properties of Steel Bolts with Different Diameters after Exposure to High Temperatures

Abstract

This research presents results from experimental studies of the mechanical behavior of steel bolts of Grade 8.8 and 10.9 after experiencing fire conditions. A significant number of steel bolts of Grade 8.8 and 10.9 of different sizes were heated according to a specific time-temperature curve and then cooled. By performing various experiments on these samples, mechanical properties of steel bolts such as stress-strain curves, elasticity modulus, ultimate strengths and the yield limit strengths of the bolts after the fire were obtained. Results from the experiments showed a quick reduction in the residual strength of the bolts when heated to temperatures of 500°C for both grades. Based on the large number of experiment results, two sets of equations for determining the mechanical properties of steel bolts of Grade 8.8 and 10.9 were presented.