Abstract: Effect of solid solution treatment on grain growth and hardness of GH4169 alloy was studied under different heating temperatures and holding time.The results show that the δ phase dissolution temperature of the alloy is between 980 ℃ and 1000 ℃.The grain growth of the alloy has different characteristics under different solid solution treatment processes.When the solution treatment temperature is lower than the δ dissolution temperature,the grain growth is slow;when the heat treatment temperature is higher than that,the grain size grows rapidly with the increase of temperature.The kinetic model of grain growth of the alloy during heat treatment above 1000 ℃ is established,with the activation energy of grain growth being 285.013 kJ/mol.The hardness of the alloy decreases with the increase of solution temperature and holding time,and the grain size and hardness of the alloy follow Hall-Petch relation.

Key words: GH4169 alloy, solution treatment, grain growth model, hardness