18Cr

18Cr refers to a classification of stainless steel characterized by its chromium content. Specifically, it denotes stainless steels that contain approximately 18% chromium. This high chromium content is crucial for imparting the corrosion resistance that defines stainless steel. The presence of chromium allows a passive oxide layer to form on the surface of the metal, which protects it from oxidation and rust.

Stainless steels with around 18% chromium are typically part of the ferritic or martensitic families, though some austenitic grades may also fall within this range depending on the precise composition. Ferritic stainless steels, like those often associated with 18Cr, are known for their good formability, weldability, and moderate corrosion resistance. They are generally not hardenable by heat treatment. Martensitic stainless steels, also potentially containing 18% chromium, offer higher strength and hardness and can be hardened through heat treatment, making them suitable for applications requiring wear resistance.

The exact properties of an 18Cr stainless steel are further influenced by other alloying elements such as nickel, molybdenum, and carbon. For example, the addition of nickel can transform a ferritic structure into an austenitic one, significantly altering mechanical properties and corrosion resistance. Common applications for 18Cr stainless steels include kitchenware, automotive trim, and various industrial components where a balance of corrosion resistance and cost-effectiveness is desired.