Intro Flashcards
pervasive problem that affects almost every aspect of our lives, from the cars we drive to the buildings we live in and the infrastructure we rely on.
Corrosion
natural process that involves the deterioration of a material as a result of chemical, electrochemical or other reactions with its environment.
Corrosion
Corrosion can occur on any material, including
metals, plastics, ceramics, and composites.
complex process that involves the loss of material from a surface due to the interaction with its surroundings, and it can occur in a variety of forms.
Corrosion
Corrosion of metals could also be considered as
extractive metallurgy in reverse.
Types of corrosion
- Uniform
- Galvanic
- Pitting
- Crevice
- Stress corrosion cracking
- Fretting corrosion
- Erosion corrosion
This is the most common form of corrosion and occurs uniformly across the surface of a metal. It is often caused by exposure to moisture, chemicals, or other corrosive agents.
Uniform corrosion
Uniform corrosion or general corrosion can be prevented through a number of methods:
Use thicker materials for corrosion allowance
Use paints or metallic coatings such as plating, galvanizing or anodizing
Use Corrosion inhibitors or modifying the environment
Galvanic corrosion occurs when two different metals are in contact with each other and there is an electrolyte (such as water) present. The more reactive metal (the anode) corrodes more rapidly than the less reactive metal (the cathode).
Galvanic corrosion
Examples of galvanic corrosion
Plate and screw of different electrical potentials due to differences in processing
❑ Multiple component implant using different metals for each component
❑Copper and steel tubing are joined in a domestic water heater, the steel will corrode in the vicinity of the junction.
❑ Pitting corrosion is a localized form of corrosion that creates small, deep holes or pits on the surface of a metal.
❑ It is often caused by the presence of aggressive chemicals or localized differences in the environment
Pitting corrosion
This corrosion occurs in confined spaces, such as gaps or crevices between metal
surfaces, where oxygen and other chemicals are limited.
❑ This type of corrosion is common in seawater or other chloride-rich environments.
Crevice corrosion
This corrosion occurs when a metal is exposed to a corrosive environment and is under tensile stress.
❑ The combination of stress and corrosion can lead to cracking and failure of the metal.
Stress corrosion cracking
type of corrosion that occurs at the interface between two surfaces that are subjected to cyclic loading or vibration.
❑ It can cause damage to metal components, such as bolts or bearings, and lead to failure.
Fretting corrosion
Erosion-corrosion occurs when a metal surface is exposed to a corrosive environment and is also
subjected to mechanical erosion, such as from flowing liquids or particles.
❑ This combination can result in accelerated corrosion and damage to the metal.
Erosion-corrosion
