Can the yield strength of ferritic steels at temperatures below ambient be estimated from room temperature values?

For ferritic steels, the yield strength at temperatures (T) other than room temperature (RT) can be estimated using the following relation published by Irwin^[1].

σ_y(T) = σ_y(RT) + 100,000/(1.8T + 491) - 190

σ_y in N/mm², T in °C.

To ensure conservative predictions, lower bound room temperature yield strength values should be used as input.

Examples are given below:

Reference

G R Irwin: 'Linear fracture mechanics, Fracture Transition and Fracture Control', Eng. Fract. Mechs, 1968, Vol.1 pp 241-257.