Effects of solid solution time on microstructure and properties of the UNS N10276 welded tube

A UNS N10276 welded tube with a size of 50.8 mm×1.5 mm prepared by cold-rolled coil through cold bending and nonmelting TIG welding was used as the raw material. It was subjected to solid-solution treatment at 1150 ℃ for 8 ~ 30 min. The microstructure and properties of the solution-treated UNS N10276 welded tube were characterized by optical microscopy, electronic universal testing machines and micro Vickers hardness tests. The results showed that with increasing solution time, the strength and hardness of the welded tube first decreased, then increased, and finally decreased. The intergranular corrosion rate of the welded pipe first decreased and then increased with increasing solution time. When the solution time was 15 min, the structure of the welded pipe recrystallized. At this time, the strength and hardness of the welded pipe were the highest, which were 1021 MPa and 276 HV1, respectively. The intergranular corrosion rate of the welded tube was the lowest, only 1.744 mm/a. A UNS N10276 welded tube with good comprehensive properties could be obtained by solution treatment at 1150 ℃ for 15 min.