ABSTRACT
Most constructional steels can fracture either ductilely or brittlely. The mode of fracture is governed by the temperature at fracture, the rate at which the loads are applied, the magnitude of the constraints that would prevent plastic deformation, and the inherent fracture toughness of the steel. In general, the fracture toughness for steels increases with increasing temperature, decreasing load rate and decreasing constraint. Furthermore, fracture toughness is governed by the thermomechanical processing used in the production and fabrication of the steel. Therefore, there is no single unique fracture-toughness value for a given steel composition even at a fixed temperature, loading rate, or constraint.
