Effect of Annealing Temperature on Microstructure, Texture and Earing of 8011 Cold Rolled Sheet

Abstract

To reduce the work hardening of the 8011 cast-rolled plates after multiple rolling, 8011 cold-rolled plates with a deformation of 78% were annealed at different temperatures. The influence of annealing temperatures exercise upon the microstructure, texture and earing of cold-rolled sheets was analysed by means of ODF texture analysis, EBSD technology and cup drawing test. The results show that the contents of the deformed microstructure, the recrystallized structure and the substructure change sharply annealing at 300°C, but they tend to be stable at 350°C. The starting temperature of recrystallization of 8011 cold-rolled plates is about 300°C. When cold rolled sheets were annealed at low temperatures, there were quantities of grain boundaries whose angle was small. When the annealing temperatures were higher, the small and medium angle grain boundaries of the cold rolled sheets decreased gradually. The general trend was that the small angle grain boundaries first increased and then decreased as the case of annealing temperature rise. The proportion of the small angle grain boundaries reached to the minimum value of 20.2% at 350°C. When annealing temperature is 350 °C, the lowest earing rate is 2.11%.