The Influence of the Strain Aging on the Mechanical Properties upon Extension in the Metal of X80 Strength Grade Pipes

Resumo

The influence of the natural aging for ten years and the subsequent heating to 680°C on the magnitude of the strain aging effect in low-carbon microalloyed 05Mn2Nb grade steel for trunk pipelines of the X80 grade pipes has been studied. A method for the assessment of the strain aging effect by the parameters of the stress–strain curve, namely, strength increment Δσ_y on the yield plateau, change in the σ_y/σ_u ratio, and proportional elongation δ_p, has been proposed.