Abstract: Microstructure and texture of Inconel783 superalloy bolts were studied, and β phase precipitation characteristic was paid special attention, meanwhile the microstructure and texture changes after stress relaxation experiment at high temperature were investigated. The results show that the grain size of γ phase is homogeneous, and γ′ precipitates distribute dispersely. Large β-phase particles are shown to align regularly, with the longitudinal axis parallel to the axis direction of bolt. The distribution of β-phase particles does not depend on the γ phase grain orientations and sizes, while it is mainly determined by smelting and hot deformation processes; the small β-phase particles precipitate at γ phase grain boundaries and inside grains, continuously or separately. Regarding texture, neither the β nor γ phase texture is strong, showing the effect of changing multi-directional stress during hot deformation. Using the axis direction of bolt as the sample reference direction x, <111>//x texture with higher intensity and <100>//x texture are observed in γ phase. The γ phase microstructure, β phase distribution and the textures of both phases are stable during stress relaxation at high temperature. By analyzing the distribution of essential small β-phase particles in Inconel783 superalloy, it is found that the precipitation behavior is influenced by the orientation of γ phase matrix and grain boundary characteristic. More small-sized β-phase precipitation occurs in <111>//x oriented γ grains, while the precipitation quantity does not show advantage at twin boundaries. It can be deduced that the precipitation of small-sized β-phase particles could be modified by controlling the grain size and texture evolution of γ phase during hot deformation and solution treatment processes.

Key words: Inconel783 superalloy, microstructure, texture, orientation, grain boundary