Corrosion Fundamentals

• Corrosion Fundamentals
• Why Metals Corrode
• Electrochemistry
• The Nature of Matter
• Electrochemical Cells
• Forms of Corrosion
• Uniform Corrosion
• Galvanic Corrosion
• Concentration Cell Corrosion
• Pitting Corrosion
• Crevice Corrosion
• Filiform Corrosion
• Intergranular Corrosion
• Stress Corrosion Cracking
• Corrosion Fatigue
• Fretting Corrosion
• Erosion Corrosion
• Dealloying
• Hydrogen Damage
• Corrosion in Concrete
• Microbial Corrosion
• Corrosion Control
• Design
• Materials Selection
• Protective Coatings
• Inhibitors and Other Means of Environmental Alteration
• Corrosion Allowances
• Cathodic Protection
• Sources of Additional Information

Corrosion fatigue is a special case of stress corrosion caused by the combined effects of cyclic stress and corrosion. No metal is immune from some reduction of its resistance to cyclic stressing if the metal is in a corrosive environment. Damage from corrosion fatigue is greater than the sum of the damage from both cyclic stresses and corrosion.  Control of corrosion fatigue can be accomplished by either lowering the cyclic stresses or by corrosion control.

The "beach marks" on the propeller shown below mark the progression of fatigue on this surface.

Similar beach marks are shown on the aerospace part below left. The high magnification scanning electron microscope image on the right shows striations (individual crack progression marks). The part shown below is also discussed in the section on fretting corrosion.

An infamous example of corrosion fatigue occured in 1988 on an airliner flying between the Hawaiian islands. This disaster, which cost one life, prompted the airlines to look at their airplanes and inspect for corrosion fatigue.