High-temperature compression and electron backscatter diffraction (EBSD) techniques were used in a systematic investigation of the dynamic recrystallization (DRX) behavior and texture evolution of the Inconel625 alloy. The true stress–true strain curves and the constitutive equation of Inconel625 were obtained at temperatures ranging from 900 to 1200 °C and strain rates of 10, 1, 0.1, and 0.01 s⁻¹. The adiabatic heating effect was observed during the hot compression process. At a high strain rate, as the temperature increased, the grains initially refined and then grew, and the proportion of high-angle grain boundaries increased. The volume fraction of the dynamic recrystallization increased. Most of the grains were randomly distributed and the proportion of recrystallized texture components first increased and then decreased. Complete dynamic recrystallization occurred at 1100 °C, where the recrystallized volume fraction and the random distribution ratios of grains reached a maximum. This study indicated that the dynamic recrystallization mechanism of the Inconel625 alloy at a high strain rate included continuous dynamic recrystallization with subgrain merging and rotation, and discontinuous dynamic recrystallization with bulging grain boundary induced by twinning. The latter mechanism was less dominant.

Friction during the hot extrusion of Inconel 625 superalloy tubes causes severe wear of the mold and plays a decisive role in the quality of the workpieces. In this paper, a ball‐to‐disk method was utilized to investigate the tribological behavior of Inconel 625 using two different tribological pairs, i.e., GCr15 and Si₃N₄, at room and elevated temperatures. Friction coefficient, specific wear rate, and morphology of worn surfaces were systematically characterized. It was found that the friction coefficients for both tribological pairs generally increased as the testing temperature increased, while the specific wear rate increased firstly and then decreased with the rise of temperature. Along with the increasing sliding speed, the friction coefficient between Inconel 625 and Si₃N₄ decreased monotonically, while the specific wear rate increased firstly and then decreased. Under any given testing condition, the friction coefficient and specific wear rate of the Inconel 625 for Inconel/Si₃N₄ pair are less than those of the Inconel/GCr15 pair. The main wear mechanisms between GCr15 and Inconel 625 are adhesive and fatigue wear at all testing temperatures. The wear mechanisms between Si₃N₄ and Inconel 625 are adhesive and abrasive wear at room temperature but fatigue wear at 500°C. Our findings indicate that the use of ceramic molds in the hot extrusion of Inconel 625 may significantly improve the surface qualities of the product and reduce the wear of the mold.