Cast Iron
Our company is one of the largest continuous cast iron trading companies. Cast iron is generally an alloy of iron with carbon. It has high resistance to pressure and temperature, but low elasticity – it is more brittle than steel.
Cast iron is produced from pig iron and cast iron and steel scrap with coke and limestone. It is melted in a melting furnace at a temperature of around 1500°C.
In our e-shop you can order:
Grey cast iron (with flake graphite)
Grey cast iron (Unibar 200, Unibar 250, Unibar 300) is a material with freely excluded graphite flakes in the iron mass. It has a relatively high compressive strength. Other mechanical properties, especially ductility, are adversely affected by the lamellar shape of graphite. Graphite flakes in the metal matrix reduce the tensile strength to only 100 to 350 MPa. The lamellar form of graphite increases thermal conductivity. Another advantage is that, thanks to the free graphite in the structure, grey cast iron can be used for low stress plain bearings. It has a considerable ability to dampen vibrations and shocks. It is not as susceptible to the adverse effect of indentations under dynamic stresses as steel is.
It is easy to machine, short and brittle chips are removed. Cast iron is only slowly corroding.
We primarily deliver grey cast iron in round and square cross-sections, or in general cross-sections (on special order). A large percentage of deliveries are thick-walled casings (hollow sections/tubes).
Ductile iron (with ball graphite)
Ductile iron has graphite excluded in the form of spheres. Compared to cast irons with flake graphite, it has higher strength, modulus of elasticity, hardness (pearlitic matrix), ductility and impact work (ferritic matrix), etc. Cast iron with ball graphite is currently the most widely used cast iron and is sometimes used instead of steel for castings. The savings that this cast iron will bring are not negligible. Compared to steel, these cast irons also have some outstanding properties. E.g. lower specific weight, good sliding properties, damping properties, better foundry properties, easier machinability, etc.
Cast iron is supplied in UNIBAR 400-15 to UNIBAR 700-2 grades, mostly in round and square cross-sections or in general cross-sections (on special order). A large percentage of deliveries are thick-walled casings (hollow sections/tubes).
Austenitic cast iron with ball graphite
Austenitic cast iron is part of the sales range as Unibar NR-F1. It belongs to high-alloy graphitic cast irons with ball graphite, where the main alloying element is nickel. It is known by the trade name Ni-Resist. The austenitic structure is achieved by alloying nickel, which is usually contained in the range of 12% to 37%. Ni-resists have many advantages over non-alloy cast irons and steels. They are resistant to wear and tear, corrosion in seawater, as well as to shaving and swelling up to a temperature of about 800°C. The austenitic structure makes them suitable for use at low temperatures down to -196°C and also when non-magneticity is required. They differ from austenitic graphite flake castings in most cases only by better mechanical properties, while the physical and technological properties are similar.
Machining of cast iron
Both our grey Unibar and ductile Unibar cast irons are widely used in the machinery and machine tool industries. Our services include precision CNC machining of this material. We machine medium and large cast iron parts, castings from grey and ductile iron.