Comments on “A unified model of environment-assisted cracking”

The history of “unified” mechanisms for liquid–metal embrittlement, hydrogen embrittlement and stress-corrosion cracking is outlined, and issues and concerns regarding a recent paper [H.W. Liu, Acta Materialia 56 (2008) 4339–4348] on a unified model of environmentally assisted cracking (EAC) are discussed.