Thermal and mechanical properties of structural steel SN400 at elevated temperatures

Abstract

The accurate estimation of thermal and mechanical properties is a prerequisite for the reliable fire-resistant design of steel structures, considering that steel is used as one of the main materials for buildings due to fast construction, light weight, and high seismic resistance. For this reason, an experimental study was performed to examine the thermal and mechanical properties of SN400, one of structural steels for buildings, at various temperatures ranging from 20 to 900oC. For thermal properties, thermal conductivity, specific heat, and expansion of SN400 were investigated. For mechanical properties, steady-state tension coupon tests were conducted. The yield strength, elastic modulus, ultimate tensile strength, and stress-strain relationships of SN400 were investigated. The measured properties of SN400 were compared with those of other mild-strength steels and predictions by current design guidelines.