Rautavalmisteita

Rautavalmisteita, or iron castings, are iron-based components produced by foundries by pouring molten iron into mold cavities. They cover gray cast iron, ductile (nodular) iron, white iron, and compacted graphite iron, and are used across automotive, machinery, piping, and construction sectors. The design often emphasizes core geometry, wall thickness, tolerances, and resistance to wear and corrosion.

Gray cast iron contains graphite flakes, providing excellent machinability and damping properties but lower tensile strength. Ductile iron uses nodular graphite for higher strength and ductility. White iron is very hard and brittle, while compacted graphite iron aims for a balance of hardness and toughness.

Most common production method is sand casting, which uses sand molds for versatility and cost efficiency. Other methods include investment casting and shell molding for tighter tolerances. After casting, components undergo fettling, heat treatment, and finishing such as machining, coating, or surface hardening.

Quality control involves chemical composition analysis, mechanical testing, and non-destructive testing, including radiography, ultrasonic testing, and dye penetrant testing, to detect porosity, shrinkage, or cracks. Surface finishing improves wear resistance, while protective coatings reduce corrosion in demanding service environments.

Environmental and industrial context: iron castings rely on recycling of scrap metal and energy-intensive processes, prompting ongoing efforts to improve efficiency and reduce emissions. Casting has a long history in metalworking and remains a global manufacturing staple.