Version | 2024/2025 | Graded A+
What is corrosion, and how does it affect materials?
✔✔ Corrosion is the chemical or electrochemical reaction of a material, usually a metal, with its
environment, leading to degradation and loss of material properties.
What are the primary factors that contribute to corrosion?
✔✔ The primary factors contributing to corrosion include moisture, oxygen, temperature, pH,
and the presence of salts or pollutants.
How does galvanic corrosion occur, and what conditions promote it?
✔✔ Galvanic corrosion occurs when two dissimilar metals are in electrical contact in the
presence of an electrolyte, leading to accelerated corrosion of the more anodic metal.
What is the difference between uniform corrosion and localized corrosion?
1
, ✔✔ Uniform corrosion affects the entire surface area of a material uniformly, while localized
corrosion occurs at specific sites, leading to pitting or crevice corrosion.
What is the role of passivation in corrosion resistance?
✔✔ Passivation is the formation of a protective oxide layer on the surface of a metal, which
helps to inhibit further corrosion by blocking reactions with the environment.
How does the pH level of an environment influence corrosion rates?
✔✔ Low pH (acidic conditions) generally increases corrosion rates for metals, while high pH
(alkaline conditions) can reduce corrosion for some metals.
What is stress corrosion cracking (SCC), and what factors contribute to its occurrence?
✔✔ Stress corrosion cracking is the growth of cracks in a corrosive environment under tensile
stress, often exacerbated by factors such as temperature, humidity, and specific corrosive agents.
How can coatings be used to prevent corrosion?
✔✔ Coatings, such as paints or galvanization, provide a barrier between the metal surface and
the environment, preventing moisture and corrosive agents from contacting the metal.
2