Stress Corrosion: Its Relation to Other Types of Corrosion

Corrosion damage can be classified into: 1) General (unlocalized) corrosion, 2) Pitting, 3) General intergranular corrosion, 4) Stress corrosion, 5) Corrosion fatigue. Of these, the first causes least weakening, while the last two cause the most weakening. Stress corrosion, differs from corrosion fatigue in requiring pre-existing paths of weakness (generally but not always intergranular); thus it occurs only on some materials after certain heat-treatments. Corrosion fatigue which manufactures its own disarrayed material as the crack proceeds can be obtained 011 almost any material exposed to alternating stresses in a corrosive environment. Preventative measures are briefly surveyed.