Effect of temperature on creep in ASTM A572 high-strength low-alloy steels

Creep deformations that occur at high temperature can significantly influence the fire response of steel structures. There is limited data on the effect of temperature on creep deformations in structural steel used in construction applications. This paper presents an investigation into temperature induced creep in high-strength low-alloy ASTM A572 steel commonly used in structural members. A set of creep tests is carried out at various stress levels in 400–800 °C range which is commonly encountered temperature range in structures subjected to fires. Results from these creep tests indicate that temperature has significant influence on the level of creep deformations in ASTM A572 steel, especially when the temperature exceeds 500 °C. The extent of creep deformation at a given temperature increases with stress level and the effect can be substantial at 550 °C when the stress level exceeds 50 % of room temperature yield stress. But creep deformations can rapidly rise beyond 800 °C even for low stress levels of about 10–15 % of room temperature yield stress.