MODELING OF ROLLING TEXTURE DEVELOPMENT IN A FERRITIC CHROMIUM STEEL

The development of crystallographic texture during rolling of a ferrit ic chromium steel containing 11 pct Cr was examined experimentally as well as by polycrystal modeling at large strains (up to 90 pct thickne ss reduction). The initial shape of the grains was very much elongated in the direction of rolling. A strong rolling direction (RD) fiber ([ 110] parallel to the rolling direction) has been observed at large str ains in the experiment. The Taylor viscoplastic model, the relaxed-con straints pancake model, and the self-consistent viscoplastic approach were employed to simulate the texture development. Strain hardening wa s accounted for by microscopic hardening laws, for which the parameter s were obtained from uniaxial tensile tests. It has been found that am ong the three models considered, the self-consistent viscoplastic mode l (the version tuned to finite-element results) yielded the best agree ment with the experimentally observed texture evolution. Strong effect s of grain shape and hardening have been found. The pancake model was also able to reproduce the main characteristics of the texture because of the flattened initial grain shape.