Resistance to brittle fracture of case-hardened steel

Abstract

1. The presence of a brittle case leads to a change in the type of macrofracture of samples subjected to impact tests — plastic deformation is prevented although the fine structure of the fracture remains unchanged. 2. A brittle case has no effect on the cold brittleness threshold. 3. In the presence of a brittle case there is no macroplastic deformation of the sample before formation of the crack (the work of crack initiation) or during propagation of the crack. 4. The impact toughness of samples with a brittle case characterizes the work of crack propagation alone.