Abstract: Influence of solution treatment on microstructure evolution and properties of nickel-based N06022 alloy pipe was investigated by metallographic microscopy, scanning electron microscopy, energy spectrum analyzer, mechanical and corrosion performance test. The results show that the cold-rolled N06022 alloy pipe contains a large amount of precipitated phases, which have a pinning effect on grain boundaries, and the average grain size of the steel is hardly affected by the holding time, when the solution temperature is below 1100 ℃. When solution temperature increases to 1150 ℃, the grain size and growth rate increase sharply, which is mainly related to the dissolution of the precipitated phase. In the solution temperature range of 1000-1200 ℃, the activation energy of grain growth for 15 min and 30 min is Q_B=646.56 kJ/mol, Q_C=566.45 kJ/mol, respectively, and the relationship between the properties of the alloy and the grain size satisfies the Hall-Petch relationship. With the increase of solution temperature, the intergranular corrosion rate of the alloy decreases first and then stabilizes, the strength and hardness show slow-fast downward trend, and the elongation shows slow-fast upward trend. When the holding time is 15 min and the solution temperature is about 1150 ℃, the intersection of hardness curve and elongation curve appears, and the corrosion rate is stable, which is the optimal solution treatment process.

Key words: N06022 alloy, solution treatment, microstructure, tensile properties, hardness