The Effect of Heat Treatment on the Evolution of Microstructure and Texture in Ti80 Hot Rolled Pipe

In this study, the microstructure and texture evolution of hot rolled Ti80 pipe annealing at 960 degrees C and 990 degrees C in alpha+beta two-phase field have been investigated. The results showed that the dissolution of alpha phases induced the increase of texture components of primary alpha phases (alpha(P)) and the alpha(P) were the main factors that determine the final texture at 960 degrees C. At 960 degrees C, the microtextures of secondary alpha phases (alpha(S)) were very close to that of alpha(P). As the annealing temperature increased to 990 degrees C, the main factors affecting the microtextures of alpha(S) changed from the alpha(P) to the recrystallized beta grains. The textures of beta phases were greatly influenced by the annealing temperature. The beta phases at high temperature were not mainly from the grow up of residual beta phases. It was formed by the transformation of alpha phases at room temperature. Consequently, this study could provide some ideas for decreasing the texture intensities of hot rolled Ti80 pipes, such as reducing the area of alpha colonies before rolling, scattering the crystal orientations of alpha(P), and controlling the size of recrystallized beta grains.