Environmental Embrittlement of Austempered Ductile Iron (ADI)– A Review

Abstract

In this article, the authors revise the advances in the understanding and characterization of the unusual embrittlement phenomenon. The phenomenon affects the behavior of austempered ductile iron (ADI) while stressed in contact with water and other liquids, reducing its strength, elongation and fracture toughness. The different investigations carried out by the authors include the characterization of the embrittlement by means of tensile, fracture toughness and cyclic load tests taking into account the influence of selected liquids. The use of electrochemical potentials during testing and the surface protection by different coatings are also discussed. These results show that there have been significant advances in the characterization of the embrittlement phenomenon since it was first reported. Based on the examination of the fracture surfaces, a fracture model, called “Localized slip process induced by adsorption in aqueous environments” is proposed.