deterioration, impairment - a symptom of reduced quality or strength

chemical action, chemical change, chemical process - (chemistry) any process determined by the atomic and molecular composition and structure of the substances involved

pitting, indentation, roughness - the formation of small pits in a surface as a consequence of corrosion

rusting, rust - the formation of reddish-brown ferric oxides on iron by low-temperature oxidation in the presence of water