Study on effects of strong shear strain on recrystallized grain size of pure iron and microstructure control method

摘要

The effects of severe plastic deformation by orthogonal cutting on static recrystallization is discussed, and a simpler microstructure control method by using metal cutting and heat treatment is proposed. Pure iron was used as a test material. Large shear strain of 6.60 and 5.04 was induced by orthogonal cutting. Chips were straightened by skin-pass rolling to produce thin metal specimens. After rolling, the specimens were subjected to heat treatment under argon gas atmosphere at 500°C and 600°C for 1 min. Microstructure was analyzed by the SEM-EBSD method and mechanical properties were measured by a tensile test. Ultrafine grained sheets with average grain diameter of 0.2 μm were produced by cutting. It was observed that different recrystallized grain structure in different heat treatment temperature. The mechanical properties of the specimen could be controlled by heat treatment conditions. The proposed method is useful to produce an ultrafine grained sheet and to control mechanical properties.