Effect Of Heat Treatment On Microstructure And Properties Of Inconel625 Alloy

Incone1625 alloy is a kind of solution strengthening nickel-base and widely used in aviation,marine and chemical engineering.The requirements of comprehensive properties such as mechanical and corrosion resistance keep improving with the wide use of incomes 625 alloy in recent years.In this paper,the effects of solution treatment on the microstructure and properties of the alloy were studied by scanning electron microscopy(SEM),transmission electron microscopy(TEM),electronic universal testing machine,Brinell hardness tester and electrochemical workstation.In order to provide effective data for safe using of alloys,the microstructure and properties evolution of the alloy during long-term aging were also studied.The effects of solution temperature and time on the microstructure and properties of the Incone1625 alloy were studied.The results showed that:solution treatment can effectively improve the plasticity and corrosion resistance of Inconel625 alloy.When the solution temperature is below 1100?,the solution temperature has little effect on the microstructure and properties of the alloy.When the temperature is raised to 1150?,the grain grew rapidly,the carbides on the grain boundaries almost completely dissolved into the matrix,the strength and hardness decreased,and the elongation increased significantly.With the increase of solution temperature,the corrosion rate decreases and the corrosion resistance is improved.The best heat treatment process is 1100?and 30min.The evolution of microstructure and properties of Incone1625 alloy during high temperature service was studied by high temperature aging experiments.The results showed that:High temperature long-term aging leaded to the strength increase and plasticity decrease.The disc-shaped?" phase precipitates were observed in the Inconel 625 alloy at 700? long-term aging and the size increased with the aging time prolonged.A large number of chain Cr23C6 carbides precipitate a small amount of acicular 8 phase precipitates were observed at the grain boundaries when aging time was 500h.A little y" phase precipitates were observed at 750? aging for 100h.?" phase gradually transformed into 8 phase and ?" phase depleted zone formed around ? phase at aging for 1000h.?"phase coarsening followed the LSW theory at long-term aging and its activation energy is about 680KJ/mol.