Improvement of Surface Ridging Resistance of an Ultra-purified Ferritic Stainless Steel by Optimizing Hot Rolling Condition

Abstract

The effects of the finisher entry temperatures (FETs) on the surface ridging behavior for an ultra-purified 21%Cr ferritic stainless steel have been investigated. The results indicate that decreasing the FET facilitates the formation of in-grain shear bands in the hot rolled slab. The in-grain shear bands supplied recrystallization nucleation sites in grains during subsequent annealing through coalescence of subgrains, which is beneficial to refine the microstructures and intensify the {111}//ND textures. This effect will evolve to the final cold rolled and annealed sheet. The micro-texture analysis indicates that the formation of grain colony in the final sheet is weakened by decreasing the FET. Then, the surface ridging resistance of FSS is enhanced due to the optimizing of micro-texture distribution.

Texture Evolution, Formability and Ridging Resistance of a Sn-bearing Ferritic Stainless Steel Under Different Hot Band Annealing Temperatures

“…12 Surface roughness profiles of final sheets after tensile testing strained by 15%: a 900 °C; b 950 °C; c 1000 °C; d 1050 °C sheets [27,28]. Currently, it is widely accepted that the surface ridging has a close relationship with the grain colonies with similar orientations [29][30][31]. Viana et al [32] proposed that the different plastic behaviors of {001} <uvw> and {111} <uvw> grain colonies that caused severe surface ridging, and meanwhile, the inhomogeneity of microstructure also resulted in a ridging.…”