Short-term creep of Cт3 steel

The behavior of Cт3 structural steel in brief heating (no more than 2 h) at 450–650°C is investigated, when the initial stress is below the yield point. In these conditions, the initial ferrite–pearlite structure of the steel is relatively stable, and no recrystallization is observed. At a test temperature of 450°C, when the stress is ~0.8 of its yield point at 20°C, Cт3 steel may fail within a matter of hours or days. At 650°C, when the stress is σ/σ 0.2 20 > 0.8 of the yield point at 20°C, failure sets in within minutes. The calculated activation energy of creep for steel is 310.8–387.8 kJ/mol, which is comparable with the activation energy for Cт3 the self-diffusion of α iron.