Inclusion deformation and toughness anisotropy in hot-rolled steels

Abstract

AbstractThe basic factors controlling the deformation behaviour of non-metallic inclusions during the hot working of steels are discussed with particular reference to silicate inclusions, alumina, and the three different types of MnS inclusion. The factors to be considered include: the initial morphology of the inclusion; the inclusion composition; the strength (hardness) of the matrix and inclusion phases at hot-working temperatures; the inclusion size; the strength of the matrix/inclusion interface; the degree of deformation; associated void/ormation. The effects of inclusion deformation and reorientation on the short-transverse toughness of hot-rolled steels are reported, with particular reference to steels containing Types I, II, and III MnS. The effects of inclusion volume fraction, aspect ratio, distribution, size, and interinclusion spacing are examined and the mechanism of short-transverse fibrous fracture is discussed in order to identify the important factors controlling toughness.