Valurautassa

Valurautassa is a term of Finnish origin that translates to "cast iron" in English. It refers to a group of iron-carbon alloys containing more than 2% carbon, along with silicon, manganese, phosphorus, and sulfur. This higher carbon content differentiates it from steel, which has a lower carbon percentage. The presence of silicon is particularly important as it aids in the solidification process of the iron.

Cast iron is produced by remelting pig iron, often with scrap iron and other additives, in a cupola or electric furnace. The molten metal is then poured into molds to create a wide variety of shapes and components. Its properties, such as good castability, machinability, wear resistance, and vibration damping, make it suitable for numerous applications.

Common types of cast iron include gray cast iron, ductile cast iron, white cast iron, and malleable cast iron. Gray cast iron, characterized by its graphite flakes, is the most common due to its excellent machinability and damping properties, and is often used for engine blocks and machine bases. Ductile cast iron, also known as nodular cast iron, has graphite in spherical nodules, giving it higher strength and ductility, making it suitable for pipes and crankshafts. White cast iron is very hard and brittle due to its carbon being present as iron carbide, making it ideal for wear-resistant parts like grinding balls. Malleable cast iron is produced by heat-treating white cast iron to form graphite clusters, resulting in improved ductility.