Cast Iron Made From New Pig Iron

- Aug 02, 2017 -



Cast iron is a series of alloys consisting mainly of iron, carbon and silicon. In these alloys, the carbon content exceeds the amount of the eutectic temperature retained in the austenite solid solution, the industrial and life cast iron carbon content often in 2.5%-4%. Cast iron is made by New Sontie, scrap steel, iron, ferroalloy and other metal burden of a variety of reasonable mix. Cast iron components are mainly iron, Iron Casting but also contains a small amount of carbon, silicon, manganese, phosphorus, sulphur, but also can be used to contain other alloying elements.

Cast iron classification methods are more, mainly:

(1) According to the characteristics of cast iron fracture: gray cast iron (gray cast iron), white cast iron, hemp cast iron.

(2) According to the graphite form of cast iron: gray iron, vermicular graphite cast iron, Iron Casting ductile iron, malleable iron.

(3) According to the chemical composition of cast iron: ordinary cast iron, alloy cast iron.

(4) The eutectic degree of cast iron is classified as: eutectic cast iron, eutectic cast iron, hypereutectic cast iron.

(5) According to the particularity of cast iron can be classified as: wear-resisting cast iron, anti-wear cast iron, corrosion-resistant cast iron, heat-resistant cast iron, non-magnetic cast iron and so on. In addition, it can be classified by the matrix of cast iron (such as ferritic ductile iron, Iron Casting pearlite ductile iron, bainite ductile iron, etc., according to cast iron production process classification (such as the inoculation of cast iron, chilled cast iron, etc.), according to cast iron alloy composition (such as aluminum cast iron, nickel cast iron, chromium cast iron, tungsten cast iron, boron cast iron, etc.). Gray cast iron (gray): Carbon is mainly in flake graphite form of cast iron, the fracture is gray, the matrix form is: ferrite, Pearlite, Pearlite and ferrite. Iron Casting The chemical composition of gray iron is generally: C2.7%--3.8% Si1.1--2 $number, Mn0.5%--1.4%, P. 3%, s<0.15%. Because Gray iron has a certain strength and good damping, wear resistance, as well as good machinability and casting process, and production simple, low-cost, so in the industrial production and civil life has been the most widely used. Breeding cast iron: Still belongs to the category of gray iron, is the iron liquid after inoculation, Iron Casting obtained the eutectic Gray iron. The carbon of the cast iron is mainly in the form of fine flake graphite, and the matrix form is pearlite and ferrite. Pre-inoculation Iron liquid (original metal) composition generally selected in the casting on the organization chart in the area of the mouth or the edge of the white area, usually controlled by: C2.8%--3.3%, Si0 6%--1 4%, Mn0.8%--1.4%., p $number, s<0.12%.

After inoculation of the inoculation of cast iron, SI is often adjusted to 1.2%-1.8%, the Eutectic group was significantly refined, the size and distribution of graphite was improved, thus increasing the strength, so the inoculation of cast iron is often called high-strength gray iron. The tensile strength of the inoculation cast iron can reach the 200--400mpa, the bending intensity can reach the 450--600mpa, Iron Casting but the elongation and impact toughness are still low, so it is often used for important castings, such as machine bed body, engine cylinder and so on, with less dynamic load and higher static strength. Ductile Iron: The iron liquid is treated by a spherical agent rather than heat-treated, so that the graphite is large or all spherical, sometimes a small amount of floc cast iron. Iron Casting But ductile iron after a certain heat treatment can change the form of matrix, Ductile iron matrix form: ferrite, Pearlite, Ferrite plus pearlite, Bainite, Austenite plus bainite. The composition of the molten iron liquid before the ball is generally selected near the eutectic point, with no graphite floating as the precondition, it is usually hoped that high carbon, low silicon, low phosphor sulfur, namely C3.5%--3. $number, Si1 0%--2 0%, Mn0.3--0. $number, P $number, s<0.8%. After the treatment of nodular iron liquid also need to be inoculated, in order to eliminate the spherical element caused by the white mouth tendency, and at the same time to refine the graphite ball, spherical inoculation after the treatment of ductile iron, SI is often adjusted to 1.8%-3.3%, magnesium residue (mg residue) control in 0.03%-0.08%, the residual amount of rare earth oxides (re residual) control in 0.02%-0.04%, do not want too high. Ductile iron is a new type of structural material developed in the the late 1940s, in addition to the good damping, abrasion resistance, machinability and casting process of gray iron, it also has much higher strength, plasticity and toughness than ordinary gray iron, Iron Casting the tensile strength can reach 1200--1450mpa, the elongation can reach 17%, the impact value can reach the 60j/cm2, so it has been used in the production of complex, strength, toughness, wear resistance and other requirements of higher parts, such as automobiles, tractors, Internal combustion engine and other crankshaft symbiosis composition. Cold-chilled cast iron, on the one hand, through the control of chemical composition to cause greater stress-cooling, on the other hand, in the process of the adoption of chilling measures.

Chilled cast iron is often used for rolls, Iron Casting especially for metallurgical rolls, in addition, it is also used for diesel tappet, tractor pulley, roller sander, and so on.

Heat-resistant cast iron: a cast iron that is oxidized or deformed at high temperatures in accordance with the requirements of use. Some alloying elements can be added to cast iron to improve the oxidation resistance and growth resistance of cast iron at high temperature.

Usually, heat-resistant cast iron according to the addition of alloying elements can be divided into three categories: silicon-containing heat-resistant cast iron, aluminum-containing heat-resistant cast iron, chromium-containing heat-resistant cast iron, mainly for sintering machine trolley, Iron Casting oil smelting furnace tube plate, furnace door, boiler grate, flue baffle, heat Corrosion resistant cast iron: is a certain corrosion resistance of cast iron. such as high silicon acid-resistant cast iron, high silicon molybdenum anti-chlorine cast iron, aluminum cast iron, high chromium cast iron, nickel cast iron, alkali-resistant cast iron, etc., Iron Casting mainly used in petroleum, chemical, fertilizer and other equipment in many parts.

Non-magnetic cast iron: A cast iron with a low permeability. The matrix structure is austenite, often called austenitic cast iron, can be divided into flake graphite austenitic cast iron and spherical graphite austenitic cast iron, mainly used for oil switch cover, transformer tail box, motor clamping ring, magnet bracket, submarine parts and so on.