Plastic deformation-induced phosphorus segregation to ferrite grain boundaries in an interstitial free steel

Grain boundary concentration of phosphorus in an interstitial free steel is observed by virtue of Auger electron spectroscopy after the alloy is plastically deformed to different strains under different strain rates at a high temperature in the ferrite region. The results reveal that phosphorus segregates at grain boundaries during plastic deformation. The segregation increases with increasing deformation until reaching a steady value, and at the same deformation amount it increases with increasing strain rate. Model predictions are made, which shows a reasonable agreement between the predictions and the observations.

Research highlights▶ Plastic deformation causes non-equilibrium grain boundary phosphorus segregation. ▶ Deformation induced segregation increases with increasing deformation rate. ▶ Non-equilibrium segregation is induced by supersaturated vacancy-phosphorus complex. ▶ Model predictions show a reasonable agreement with the observations.