Plastic Deformation Behaviours of Anisotropic Materials (Study on Deformation Behaviours by Taylor's Model)

The stress of each grain in anisotropic materials having a texture under uniaxial tension was analyzed by using G. I. Taylor's model. The average lattice strain in grains subjected to the X-ray diffraction was also calculated by taking account of the stress condition and the volume fraction of grains. The results were examined experimentally by means of the X-ray diffraction method for hot rolled steel sheets. The results obtained are summarized as follows. (1) The lattice strain of anisotropic materials depended upon the tensile direction of the specimen and differed from that of the materials without a texture. (2) The calculated values of the lattice strain agreed well with the experimental results, indicating that the stress in each grain depends upon its orientation of crystal and the critical resolved shear stress in each slip system can be regarded as equal in the initial stage of the plastic deformation. (3) The values of the residual lattice strain calculated on the assumption that the stress in each grain decreased uniformly in the unloading process after the plastic deformation coincided qualitatively with the experiment. (Received June 2, 1980).