Effect of Annealing Temperature on the Microstructure, Mechanical Properties and Fracture Behavior of AISI 304 Foils

In the current work, the effect of annealing temperature on the microstructure, mechanical behavior and fracture mechanism of AISI 304 foils were analyzed by a series of electron back-scatter diffraction tests and tensile tests. The results show that the microstrcuture of the as-received specimen and the specimen annealed at 750 °C was dominated by the α fiber and γ fiber. With the increase in annealing temperature to 950 °C, a more homogeneous microstructure was formed and thereby improving the mechanical properties of AISI 304 foils. Nevertheless, both the elongation and tensile strength decrease dramatically due to the easy occurrence of in coordination deformation in coarse grains with further increase in annealing temperature to 1150 °C. Also, a large number of micro-dimples were formed on the fracture surface of AISI 304 foils annealed at 950 °C, indicating that the enhanced ductility was achieved owing to the improvement in material homogeneity and the decrease in the degree of local plastic deformation. Overall, an optimal annealing temperature of 950 °C is obtained in order to improve the mechanical properties and fracture behavior of AISI 304.