A metal consists of crystals, or grains, whose atomic arrangement is regular together with amorphous (structureless) metal surrounding them. Corrosion of the weaker amorphous metal, due to galvanic action in sea water, can take place. if stresses are 'locked up within the metal they can be partly relieved by the corrosion thereby exposing more amorphous metal to corrosive attack and progression of the process until it leads to possible failure. Stress corrosion is most commonly found in brasses, but it has occurred in aluminium alloys and stainless steels. Caustic embrittlement to be discussed later is another form of stress corrosion.