Influence of Microstructural Inhomogeneity on the Formability and Fracture of a Carbon Steel

The dependence of drawability in carbon steel on the grain size shows that a finer grain size is desirable for the better production. On the other hand, the characteristics of fracture in Olsen cup test are determined by the microstructural inhomogeneity. Several microstructures are prepared by adequate heat treatment and the formability and fracture mode are examined from the point of view of microstructural inhomogeneity. Good correlation between the second phase distribution and the formability in deep drawing is obtained. An anisotropic factor R/ΔR also well explains the formability.