Correlations Between the Rolling Textures in FCC Ni–Co Alloys and the BCC Transformation Textures in Controlled Rolled Steels

Abstract

Three fcc Ni–Co alloys with different stacking fault energies (SFE′s) were cold rolled 95% and their textures were characterized by the orientation distribution function (ODF) method. BCC transformation textures were calculated from these experimental textures using three different orientation relationships for the γ → α transformation. The transformed ODF′s derived from the Bain relationship were much sharper than the ones deduced from the Kurdjumov–Sachs (K–S) or the Nishiyama–Wassermann (N–W) relations. The ferrite texture determined on a controlled rolled steel, heavily deformed in the unrecrystallized γ region, agrees reasonably well with the bcc texture calculated using the K–S relation from the rolled Ni–Co alloy with similar SFE. The major texture components of the ferrite, namely {332}〈113〉 and {311}〈011〉, are found to originate from the two major rolling texture components of the austenite, i.e. the {110}〈112〉(Bs) and {112}〈111〉(Cu), respectively. Such ferrite transformation from heavily deformed austenite seems to follow the K–S relationship without any variant selection. By contrast, the texture of the martensite produced from deformed austenite appears to involve significant amounts of variant selection.