How is ductile iron made?
Ductile iron is made by the treatment of molten iron with no- dulizing (spheroidizing) material. During this treatment, gra- phite changes from flakes to nodules or spheres. The treatment process is a key operation in the production of ductile iron that ensures a predetermined microstructure, and mechanical and engineering properties of castings.
What happens during the treatment process of ductile iron?
During this treatment, gra- phite changes from flakes to nodules or spheres. The treatment process is a key operation in the production of ductile iron that ensures a predetermined microstructure, and mechanical and engineering properties of castings.
What properties make ductile iron a suitable replacement for steel?
Other properties such as vibration damp- ing, machinability, and wear resistance have made ductile iron a suitable replacement for steel in gears and a number of other applications. The main structural difference between nodular cast iron and gray cast iron is in the graphite form.
How is free-oxygen free in ductile iron?
In ductile iron production, molten metal is treated by adding magnesium, which has a high affinity for free-oxygen atoms. Hence, the level of normal oxygen atoms in ductile iron is lowered from parts-per-million to parts-per-billion, an extremely low level of oxygen-atom contamination.
What is ductile cast iron?
Abstract—Ductile cast irons are materials having strength, impact toughness and ductility comparable to those of many grades of steel while exceeding by far those of standard gray irons. In addition, they have the same advantages of design flexibility and low cost casting procedures of cast irons.
What is added to iron to make it a solid?
Carbon is added to iron in amounts that exceed the solubility limit, and during solidification, graphite precipitates into tiny spheres. Silicon and other alloys are used to control the mor- phology of the precipitated graphite and to control the amount of carbon that remains as a solid solution in the iron.
What is the difference between gray and nodular iron?
Ordinary gray cast iron is characterized by a distribution of random lamellae of gra- phite in the metal matrix, while in nodular cast iron the gra- phite has the form of small spheroids.
What is ductile iron?
Ductile iron consists of various materials manufactured to have many far-ranging properties. The addition of a small amount of cerium or magnesium to gray iron prior to casting results in a unique microstructure and set of mechanical properties.
What is the whole point of ductile iron?
Of course, the ductile iron manufacturing process’s whole point is the cast metal into usable parts and components. After solid materials get rendered molten in a blast furnace, the molten metal is poured into a mold cavity containing the desired shape.
How wide is ductile iron?
Ductile iron pipes generally come in a length of six meters and range from 60 mm to 2m or 3m in width. That said, these values vary by the factory and the country of origin.
What is the first machine in ductile iron manufacturing?
The first machine we want to highlight in the ductile iron manufacturing process is the blast furnace. When you walk into a ductile iron manufacturing plant, you can recognize the blast furnaces by their tower-like appearance.
How long does cement mortar cure on ductile iron pipe?
Then, the pipe gets spun for a few seconds to smooth out the cement and ensure thickness consistency. This process seals the surface. Then, the cement cures for 24 hours.
How hot does a cast iron pipe get?
Freshly cast pipes register piping hot temperatures of 850 degrees Fahrenheit, but they cool rapidly after leaving the mold. This rapid cooling renders the iron brittle. For this reason, the pipes next go into a gas-filled annealing furnace. This furnace reheats the pipes to about 950 degrees Fahrenheit.
What is used to make pig iron?
Nevertheless, the processes that occur within the furnace have remained the same as the ingredients. Iron ore, coke, and limestone are all utilized to produce pig iron.