Room temperature creep of a high strength steel

The time dependent deformation at room temperature of a high strength steel was investigated. The room temperature creep tests showed that creep can occur below 1/3 sigma (0.2) (yield strength at 0.2% offset). The resulting creep behavior consists of only two stages, including primary creep and steady-state creep, each of which has its own distinctive strain-time features. The effects of creep stress, creep time, steel hardness and heat treatment schedule on the room temperature creep were investigated. It is believed that the increased creep strains can be attributed to higher applied stresses, longer creep times, lower hardnesses and the existence of an inhomogeneous microstructure. However, increasing the number of cycles in cyclic creep tests at room temperature resulted in a decrease in creep strain. Possible room temperature creep mechanisms have been proposed and discussed. (C) 2001 Elsevier Science Ltd. All rights reserved.