Industries that use gray iron castings include: agriculture, construction, automotive, construction, electronics, irrigation, machine building, transportation and ventilation.
Gray iron castings provide durability, hardness and strength to any operation in which they are used. There are many applications for gray iron castings. As non-combustible building elements, they provide excellent fire protection for wooden support structures. Additionally, their graphite/graphite flake content can be used for energy dissipation in components such as engine blocks and crankshafts, which depend on the damping of mechanical vibrations.

Material Technology
The generally accepted composition of gray cast iron is 95% iron by weight, plus 1% to 3% silicon and 2.1% to 4% carbon.
The large amount of silicone in gray iron produces graphite when heated. Graphite is the element that causes the coloring of gray cast iron. Gray graphite can be seen when gray cast iron breaks. When it ruptures, graphite flakes are produced, evidence of its graphite microstructure. In its natural form, graphite flakes look like true flakes. On a polished surface, cast iron graphite flakes appear as thin lines. Graphite flakes crack easily, a property that actually makes gray iron more castable. All in all, gray iron has a graphite content between 6% and 10% by volume.

The presence of carbon changes the tensile strength and hardness. The higher the carbon content, the higher the tensile strength and hardness.
The exact appearance of individual gray irons depends on temperature and time. In addition to appearance, variable properties of castings include: thermal conductivity, tensile strength, hardness, energy dissipation, wear resistance and deformation, and melting point.

Other elements may be present in gray iron castings. Some may have been intentionally placed there by the manufacturer to alter specific properties. Others, like graphite, may appear by chance. The most prominent of these are manganese, carbon and sulfur. When added to molten gray cast iron, manganese promotes the formation of pearlite during the cooling phase, while sulfur increases hardness. Other elements may be present, but to a lesser extent.

process details
1. To obtain gray cast iron, metalworkers must first mine iron ore or iron oxide and then process it in a special type of blast furnace called an induction furnace or cupola.
2. When the metalworkers have reached their desired mix of gray iron material, they start casting.
3. Ironworkers can use a variety of processes to produce gray iron castings, although they all follow more or less the same basic procedure. First, the gray cast iron is liquefied and poured into molds, which are then released after cooling.
4. No matter what method is used, many times the newly formed castings need to be processed twice after casting, for finishing, to remove burrs, scale and other defects. These processes include deburring, annealing, machining, galvanizing, painting, etc. In order to produce more finished products, most iron foundries are equipped and staffed to carry out such processes on the shop floor.