Ferritisch

Ferritic refers to a class of steels that have a body-centered cubic (BCC) crystal structure at room temperature. This structure is known as ferrite. Unlike austenitic steels, which have a face-centered cubic (FCC) structure, ferritic steels are typically non-magnetic and cannot be hardened by heat treatment, though they can be strengthened by cold working.

The ferritic phase is stable at higher temperatures in plain carbon steels, but it persists down to room temperature in certain alloy compositions, particularly those with a high chromium content. Stainless steels that are primarily ferritic, such as grades 430 and 409, are characterized by their good formability and corrosion resistance, especially against oxidizing environments. They generally offer better resistance to stress corrosion cracking than austenitic stainless steels.

However, ferritic stainless steels have limitations. They tend to be less ductile and tougher than austenitic grades, particularly at low temperatures, and can be susceptible to sensitization if exposed to high temperatures for extended periods, which can reduce corrosion resistance. Their mechanical properties can also be influenced by grain size, with coarser grains often leading to reduced toughness. Despite these drawbacks, their cost-effectiveness and specific performance characteristics make them suitable for a range of applications including automotive exhaust systems, kitchenware, and architectural trim.