passivité

OBS: La rupture de passivité peut mener à la piqûration.
OBS: On englobe parfois dans cette définition l'état d'une surface recouverte d'un film très mince de phosphate ou de chromate, tel qu'il se forme par immersion dans des solutions contenant de l'acide phosphorique et/ou de l'acide chromique. Cet usage est incorrect et n'est pas recommandé.

CONT: The passivity of metals and alloys is one of the most important phenomenon responsible for out metal-based civilization. Most structural metals are viable in an engineering sense only because of the existence of a surface oxide film whose thickness may be less than a few nanometers. Although the phenomenon of passivity has been known for more than 150 years, a satisfactory description of the passive state still eludes us.
OBS: Passivity breakdown often leads to pitting.