Rustfrit

Rustfrit is a term used to describe materials that resist corrosion, most commonly stainless steel. Stainless steels are iron-based alloys that contain a minimum of chromium, typically at least 10.5%. The chromium forms a thin, passive oxide layer on the surface that protects the metal from further corrosion. This passive layer is self-repairing, so minor damage is quickly healed by chromium oxide.

Composition and families: In addition to chromium, stainless steels often include nickel, molybdenum, and sometimes nitrogen or vanadium. These elements tailor corrosion resistance, strength, and weldability. Main families include austenitic (e.g., 304, 316), ferritic, martensitic, and duplex grades. Austenitic steels are non-magnetic and highly formable; ferritic and martensitic are generally cheaper and magnetic, with different weldability profiles.

Properties and limits: High corrosion resistance in many environments, good formability, and a wide range of strengths. They can be sensitive to pitting in chloride-rich environments, especially at high temperatures or in low-quality grades; proper care and appropriate alloy choice mitigate risks.

Applications and standards: Applications include kitchenware, medical devices, architectural elements, chemical processing equipment, and automotive parts. Common grades are 304 and 316; standards include EN 10088 and AISI/SAE grades. The term rustfrit is often used in everyday language to refer to stainless steel in general.

Care and maintenance: Cleaning with mild detergents, rinsing, and drying helps preserve the surface. In chloride-rich environments, passivation and regular inspections help maintain the protective layer. Avoid prolonged exposure to harsh cleaners that can damage the passive film.