Fatigue cracking accelerated by a corrosive environment. Corrosion pits act as crack starters and the environment speeds crack growth, so a part cycling in seawater or wet process service fails at lower stress or after fewer cycles than the same part in dry air, and steel loses the endurance limit it shows in air. Offshore structures, pump shafts, boiler tubes and sucker rods are common victims.
Shaft broke at a pit in the keyway, beach marks across the face, that's corrosion fatigue, not overload.
Also heard as
- CF
Related terms
SCC
Stress corrosion cracking: brittle cracking caused by tensile stress acting together with a specific corrosive environment.
Pitting
Localized corrosion that drills small, deep cavities into metal while the surface around them stays nearly intact.
Hydrogen embrittlement
Loss of ductility when atomic hydrogen gets into steel, leading to sudden cracking under stress.