An experimental investigation of the mechanical strength of cold-drawn AISI 1018 steel under high-temperature steady- and transient-state conditions

Abstract

Generally, in the event of a fire, steel structures exhibit different characteristics in terms of mechanical property degradation, which is significantly affected by the manufacturing of the steel. Therefore, the mechanical properties of cold-drawn AISI 1018 steel (CDS 1018) at elevated temperatures under steady- and transient-state conditions were investigated. The thermal expansion of CDS 1018 is relatively less than the thermal expansion predicted using Eurocode and ASCE standards at temperatures ranging from 25 to 650 °C. Dynamic strain ageing (DSA) improves the mechanical strength of CDS 1018 at steady-state temperatures ranging from 400 to 500 °C. Under transient-state conditions, the mechanical strength of CDS 1018 is better than those of high-strength steel (HSS) and ultrahigh-strength steel (UHSS) grades in the temperature range of 500–600 °C. Application of the cold-drawing process to AISI 1018 steel provides thermal creep resistance at temperatures up to 600 °C. The current design standards from the Eurocode, ASCE and AISC cannot be adapted for the fire-resistant design of structural mild steel delivered by cold-drawing conditions. Therefore, the present experimental data series obtained from steady- and transient-state methods are applicable to predict the mechanical degradation of CDS 1018 for engineering applications in fire-safety design.