Environment-Sensitive Fracture of Austempered Ductile Iron

The embrittlement of austempered ductile iron has been studied as a function of aqueous solution composition and of applied potentials. The extent of the embrittlement does not show marked dependence upon potential or the species present in water, and only the latter appears to be the critical substance for embrittlement. It is tentatively suggested that the water is effective in lowering the surface energy for fracture, which is accompanied by some small amounts of plastic deformation.