Research on the Structure and Low-Temperature Annealing Effect in Cold-Rolled α-Brass. II : Structures Cold-Rolled and Annealed at Low Temperatures

The structure changes by cold-rolling and low-temperature annealing of 70/30 brass were examined by a microscope and X-ray photography. The difference in ready-to-finish grain size affected the degree of development of the rolling structure. A coarse-grained material tended to delay the development, compared with a fine-grained one. The tendency seemed to relate to the hardness change by low-temperature annealing as previously reported. No remarkable change in structure was observable by annealing at 150°, while a kind of polygonization was seen at 250°. Though the nucleation by recrystallization developed preferentially at the regions strained severely, grain growth was observed along the slip lines at 350°. The difference in grain size affected the rate of recrystallization