The Effect of Banded structure and Sulfide Morphology on the Anisotropy of tensile Ductility and Impact Toughness
박종우Jong Woo Park, 김정석Jeong Seog Kim, 문인기In Ge Moon
Abstract
Effects of pearlite banding and sulfide morphology on the anisotropy of tensile properties and impact toughness were studied in hot rolled C-Mn steels. Homogenizing treatment and sulfide shape control by the rare earth metal addition were used to change the pearlite distribution and sulfide morphology. It is believed that the planar anisotropy of tensile ductility is primarily due to the elongated sulfide rather than pearlite banding. However, the anisotropy in impact toughness is associated with both the pearlite banding and sulfide morphology. The pearlite banding is the cause of anisotropy associated only with notch orientation, whilst the elongated sulfide is the cause of anisotropy associated with both notch and specimen orientation. Homogenizing treatment improved the anisotropy in ductility and toughness by eliminating the pearlite banding and by subdividing and rounding the elongated sulfides.