Regularities of Crystallographic Texture Formation in Austenitic Steel during Rolling and Tensile Testing

AISI304 steel samples cut from a forged rod were rolled at room temperature using longitudinal and cross schemes, after which they were subjected to various heat treatments with cooling from temperatures of the two-phase α+γ- and single-phase γ-regions to fix different phase compositions. The phase composition was studied, the volume fractions of austenite and α-martensite, crystallographic texture, structure and substructure of two-phase steel were determined, uniaxial tension tests of rolled sheets in different directions were carried out to evaluate the anisotropy of mechanical properties. It was found that the occurrence of γ → α phase transformations during deformation significantly depended on the rolling scheme and conditions, and the amount of remaining austenite varied within 15–29%. The reverse α → γ phase transformation initiated by annealing in the single-phase γ-region leads in the case of longitudinal rolling to the multiplication of the γ-phase texture components and the appearance of an additional orientation 113, while in the cross scheme the texture of deformed austenite is preserved. Quenching in the two-phase region at 700°C does not lead to a fundamental change in the austenite texture, but ensures the appearance of additional martensite components 110 and 112. The texture features affect the anisotropy of elastic properties and yield strengths: the anisotropy of the Youngs modulus of samples consisting entirely of austenite is higher (ETD/ERD = 1. 67) compared to 1. 25 for samples of quenched two-phase steel.