Cast Iron Bars produced in Continuous Casting
The cast iron bars produced in horizontal continuous casting differ from the cast iron produced in casting by other processes for the absolute absence of defects inside the bar and the high structural compactness, indeed guaranteed from the method of production (for more information and the sketch of the production plant, see the technical catalogue). These technical features, besides the stock availability in different standard sections, make it particularly suitable for the construction of components for the hydraulic field and mechanical components in general.
The main characteristics which make the cast iron in continuous casting advantageous compared to the normal sand casting are the following:
- Total absence of anomalous shrinkages due to poor feeding in the cooling phase (as the supply of liquid pig iron from the melting furnace to the bar is continuous during the cooling phase).
- Total absence of gas porosities or inclusions of sand or slags inside the cast iron bars (as eventual defects of this type, if occasionally present, are concentrated on the external surface of the bar and are removed with the machining allowance).
- High compactness of the structure, due both to the forced cooling and the strong ferrostatic pressure exerted by the liquid metal contained in the melting furnace on the section of the cast iron bar.
- High stability of the cast iron bar because, during the casting process, the outside is rapidly cooled, while the heat of the core, still liquid, makes an heat treatment of stabilization and annealing of the external area, eliminating the stress inside the bar almost completely.
- Very short delivery time, because it is standard material normally ready at stock
Types of cast iron and technical features:
Cast iron is by definition an Iron – Carbon alloy in which the content of Carbon (C) exceeds 2,1%. The carbon in the cast iron solidifies in the shape of graphite. The graphite can be in lamellar or spheroidal shape; these two types of carbon solidification give rise to the two main families of cast iron, the Lamellar cast iron and the Ductile Cast Iron. These two families are then divided into two subgroups according to the ferrous matrix of the alloy: Ferritic Cast iron and Pearlitic Cast Iron, each one with different characteristics.
The cast iron bars produced in continuous casting are normally available in:
- Ductile Cast Iron EN-GJS in different types (EN-GJS.400-14C fully ferritic; EN-GJS.400-7C ferritic-pearlitic; EN-GJS-500-7C ferritic-pearlitic, EN-GJS.600-3C pearlitic and other types on specific request).
- Lamellar Cast Iron EN-GJL in different types (EN-GJL.250 C-pearlitic-ferritic, EN-GJL.300-C mainly pearlitic and other types on specific request).
- Lamellar Cast Iron “G.M.I.” (Glass Mold Iron) with fully ferritic structure.
Commerciale Fond has well-stocked warehouses in all its locations to guarantee prompt deliveries of cast iron bars with the following sections:
- Round from Ø20mm. to Ø630mm.
- Square from 20x20mm. to 500x500mm./li>
- Rectangular from 40 x 20mm. to 730 x 95mm. or 610 x 410mm. and other sections.
- Special sections, like half round, 3 lobes section or others specially made according to customer’s specifications.
Besides the maximum sizes mentioned above it is possible to supply cast iron bars produced in chill casting, a method which, thanks to the rapid cooling of the metal, allows the realization of Round blocks in cast iron up to Ø1’200mm. and Rectangles up to 1’000 x 700 x 1’500mm. both in lamellar cast iron (EN-GJL) and ductile cast iron (EN-GJS). This material is always supplied with pre-machined external surface, by milling or turning.
The cast iron bars with standard sizes have a length of 3’000mm (-0/+ 200mm.) which is reduced to 1’880/2’000mm. for material with big dimensions and half round bars, while the bars produced in chill casting usually have a length of 1’000mm.
All cast iron bars can be supplied cut to size or pre-machined by milling on 4 sides or by peeling the bars with round section (see “Services” in the technical catalogue).
All cast iron bars commercialized by Commerciale Fond are produced by foundries with “Quality System” certified in accordance with the Standard UNI EN ISO 9001-2008 and with “Environmental Management System” certified in accordance with the Standard UNI EN ISO 14001.