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WEA White Etching Area

Chemical designationWEA White Etching Area
StateWEA White Etching Area
Etching3 % Nital

These non-etchable white layers consist of tetragonal (i.e. non-tempered) martensite and are also referred to as grinding burn. These areas also occur in rolling bearings, often close to oxide inclusions. Causes for this zone can be: grinding burn, excessive surface pressure, slipping bearing seat, wire ropes rubbing against each other.

White zones also occur during wire erosion. Self-quenching takes place in the edge zone due to the melting away of the material. An edge zone change also takes place in titanium (Link).