Stress Corrosion:



Stress Corrosion

 Stress corrosion of the metal formed by the combined effect of a tensile stress and a specific corrosive environment on the metal., during stress corrosion, the metal or alloy is virtually unaffected over most of its surface, while fine cracks progress through it normal to the direction of tensile stress. The stress on the metal may be internal or external and these stress is due to some mechanical or service conditions. The metal atoms under stress are always at higher energy level so acts as anode and stress free parts of metal acts as cathode under specific corrosive environmental conditions corrosion process starts.

• Brass undergoes corrosion in the presence of ammonia.
• Stainless steel in the presence of Cl^- and caustics.  But best example for stress corrosion is caustic embrittlement.