- The component that most significantly influences the corrosion resistance of stainless steel alloys is the chromium content.
- Chromium plays a crucial role in enhancing the corrosion resistance by forming a thin, stable, and adherent oxide layer called the passive film on the surface of the stainless steel.
- This passive film acts as a protective barrier that prevents further oxidation and corrosion, even in harsh environments.

- While other elements like nickel contribute to the alloy's overall mechanical properties and stability, and carbon and manganese affect hardness and strength, they do not provide the same level of corrosion protection as chromium.
- Stainless steels typically require a minimum of about 10.5% chromium to achieve this passive layer formation.
- Increasing the chromium content generally improves corrosion resistance, particularly against rust and oxidation.

In summary, the key to the corrosion resistance of stainless steel is the presence of sufficient chromium, which ensures the formation of the protective passive oxide layer.

Reference: Metallurgy of Stainless Steel, Volume 2, Chapter 5, Page 112