Pitting Corrosion Quiz

Pitting Corrosion Overview

• Pitting corrosion is a localized form of corrosion that leads to the creation of small, deep pits or cavities on a metal surface.
• It often occurs in metals that have a protective oxide layer, where the layer can be disrupted, leading to localized attack.

Driving Power for Pitting Corrosion

• The driving force for pitting corrosion is the electrochemical potential difference between anodic (active) and cathodic (passive) sites on the metal surface.
• Factors such as chloride ions, temperature, and pH can enhance the likelihood of pitting occurring.

Development of Pitting Corrosion

• Pitting corrosion typically starts when protective films on a metal surface are damaged or disrupted.
• The presence of aggressive ions like chlorides assists in breaking down the protective oxide layer, leading to localized corrosion.
• Once initiated, the pit can grow deeper while remaining small in diameter, making it difficult to detect.

Effects of Pitting Corrosion on Metal

• Pitting corrosion can compromise the structural integrity of metals, leading to failure through unexpected fractures or leaks.
• It often leads to a reduced lifespan of the affected metal components due to increased vulnerability to continued corrosion.
• The localized nature makes pitting difficult to monitor, which can result in unforeseen maintenance costs and safety hazards.

Electrochemical Reactions in the Absence of Oxygen

• In an oxygen-deprived environment, the electrochemical reactions during cathodic processes can alter, affecting the rate and extent of pitting corrosion.
• The absence of oxygen can change the type of cathodic protection processes, making metals more susceptible to localized corrosive attacks.