Abstract: Cryogenic treatment is widely used at present because of its simple operation, low price, and obvious improvement of material properties. Inconel 617 alloy was tested under different times and numbers using Cryogenic treatment. The microstructure of Inconel 617 alloy was investigated by scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM), and the tensile test was carried out at room temperature by the universal tensile testing machine. The results show that the grain size of Inconel 617 alloy is refined after cryogenic treatment. After single cryogenic treatment for 12, 24 h, the fraction of low-angle grain boundaries increases, which is helpful to improve the tensile strength and ductility of the alloy. However, after cryogenic treatment, a large number of carbides are precipitated in the alloy, which reduces its strength.

Key words: Inconel 617 alloy, cryogenic treatment, grain boundaries, carbides