Structure Formation of the Nitrogen-Containing Austenitic 04Kh20N6G11M2AFB Steel at Hot Deformation: Part II. Influence of the Phase Composition and Conditions of Hot Deformation on the Process of Dynamic Recrystallization

Abstract

The impact of δ-ferrite in high-strength corrosion-resistant nitrogen-containing 04Kh20N6G11M2AFB steel on deformation resistance during hot deformation within the temperature range of 900–1200°С and strain rates of 0.1–10 s^–1 was investigated. Analysis of diagrams shows that dynamic recrystallization of δ-ferrite steel starts at a lower threshold deformation rate compared with pure austenitic steel. The values of the deformation threshold necessary for the initiation and development of dynamic recrystallization depending on the phase composition of the nitrogen-containing steel were determined. The complex analysis of the structure proved that δ-ferrite contributes to the nucleation and development of dynamic recrystallization at 1200–1000°C (its initiation corresponds to the lowest deformation threshold) and formation of the recrystallized structure in a larger volume as compared with the purely austenitic structure.