Effect of cold drawing on environmentally assisted cracking of cold-drawn steel

The fracture behaviour in air and aggressive environments of two eutectoid steels in the forms of hot-rolled bar and cold drawn wire has been compared to elucidate the consequences of cold drawing on their susceptibility to environmentally assisted cracking (EAC) in aqueous environments. Cold drawing produces a microstructural effect on the material: a preferential orientation of the pearlite lamellae aligned parallel to the cold-drawing direction, resulting in anisotropic properties with regard to fracture behaviour in air and aggressive environments. The main consequence is the change in crackpropagation direction approaching that of the wire axis (cold-drawing direction or main average orientation of the pearlite lamellae) and producing a mixed-mode state. The results reported provide insight into the macro- and micro-mechanical effects of cold drawing on the fracture and EAC-behaviour of eutectoid pearlitic steels.