Modeling the effects of grain boundary sliding and temperature on the yield strength of high strength steel

To ensure the safety of high strength steel in application, the yield strength is a vital parameter especially at elevated temperatures. In this work, on the basis of the Force-Heat Equivalence Energy Density Principle, a temperature dependent model of grain boundary sliding energy is developed firstly. Then, a physics-based model, which considers the effects of grain boundary sliding and temperature on the yield strength of high strength steel is proposed. Compared with the leading design standards including fitting parameters, such as American Society of Civil Engineering, Australian Standard, American Institute of Steel Construction and Eurocode 3 Design of Steel Structures, better agreement is obtained between the theoretical predictions and available experimental data of high strength steel fully validates the reasonability of this model. Meanwhile, this theoretical model offers an appropriate assessment method for yield strength at elevated temperatures of high strength steel, reducing the consumption of including time and manpower.