Measurement and modelling of textures in flow formed Cr-Mo-V steel tubes

Flow formed components undergo a complex deformation mode under biaxial strain, which is expected to have significant impact on the crystallographic texture evolution. X-ray diffraction measurements and calculations of orientation distribution functions (ODFs) were employed to analyse flow formed tubes produced with different parameters such as preform hardness, feed rate, roller contact angle, and wall thickness reduction. Texture variations were observed both throughout the wall thickness and along the tube length. A crystal plasticity finite-element model was used to decipher the texture formation relative to the imposed axial and hoop strains. The shear strain on the axial-hoop plane was found to be responsible for the deviation from cold rolling textures and the formation of a fibre along Phi = 0 degrees in the (phi(2) = 45 degrees ODF section. Finally, annealing treatments at 700 degrees C were carried out to monitor texture changes due to potential recrystallisation effects during the forming process, upon which strengthening of the {113} < 1-10 > orientation was noted.