Recrystallization Kinetics, Precipitate Evolution and Grain Refinement of Nb Stabilized Ferritic Stainless Steel for Producing Thicker Plate/Strip Industrially

Abstract

The study focuses on the processing of thick plate (≥ 12 mm) and strip (3 to 4 mm) where hot-rolling reduction is comparatively less. The recrystallization kinetics of hot-rolled plate was studied with detailed microstructural and texture evolution during annealing. The investigation was further extended to cold-rolling and annealing considering the industrial application in thicker strip production. Microstructure, texture and precipitates were characterized and mechanical properties were correlated with the processing schedule and microstructural parameters. Fine and recrystallized hot-band structure is required to get the desired fine microstructure in cold-rolled and annealed condition. Higher hot-band annealing time facilitated significant precipitation providing enhanced strengthening after cold-rolling and annealing treatment in spite of having coarser grain size. Mechanical properties were directly correlated to the high-angle, low-angle grain boundaries and geometrically necessary dislocations in the investigated steel. © 2023, The Minerals, Metals & Materials Society and ASM International.