Cast iron is one of the starting products in the manufacturing process and its flow chart shows the importance of cast iron in the steel industry. Cast iron is a member of the ferroalloy family and is one of the most widely used alloys in industry. Iron, carbon, and silicon are the main elements of this alloy. Of course, certain amounts of other metals and elements (such as manganese, phosphorus, sulfur, etc.) can also be used in this alloy, but their presence is not permanent, and depending on various factors and conditions, they are added to cast iron. Cast iron is available in various shapes and types on the market. Each of these types has its own properties and characteristics. These properties make it possible to use cast iron in various industries Cast iron is an iron alloy with a higher percentage of carbon and silicon than steel. This alloy is produced in white, gray, brittle, ductile, and compressed graphite types. 
What is cast iron? The difference between it and steel Both cast iron and steel are iron alloys, but the presence of silicon in the cast iron mixture creates the difference between cast iron and steel, and the characteristics and properties of both. First, we will cover cast iron in its entirety, then we will examine how it differs from steel. The History of Cast Iron Manufacturing Today, cast iron is less used in the construction industry, but there are still some cast iron tools that are used in the petrochemical and oil refining industries and are reasonably priced. For example, considering its quality and strength, the price of cast iron valves in the market is very reasonable compared to other types of valves used in the petrochemical industry. But about its history, it can be said that the main ingredient of cast iron is more than 1000 years old. When iron was discovered in human life, it was used by people for various purposes. Humans use iron to make agricultural implements, weapons of war, and other powerful tools they need. This made blacksmithing an important task at the time. Gradually, people thought of using iron in other ways. For this reason, iron is melted and mixed with various materials. One of the substances combined with molten iron is carbon. Years later they added a new element called silicon to this composition and called it cast iron. Cast iron was very popular and widely used in the 18th century, and in England a style known as cast iron construction was established due to the extensive use of cast iron in building and construction. 
Chemical composition of cast iron As we said from the beginning, cast iron consists of three main elements and some minor elements. But when these elements are combined with each other, a certain amount of elements should be included in the composition so that the cast iron retains its properties and does not contain large amounts of impurities. In this composition, iron has the largest share of about 92%. This is followed by carbon, which makes up about 2-4% of the cast iron composition, and then 1-3% silicon, leading to the difference between steel and cast iron. That leaves about one percent, which is specific to less common elements in cast iron compounds.
- manganese
- phosphorus
- Sulphur
Sometimes other elements (in varying amounts) are added to cast iron to change its structure and properties. These elements are:
- aluminum
- magnesium
- copper
- sodium
- Chrome alloy
- vanadium
- other metals
- Features of cast iron
The uniqueness and specialness of cast iron makes it popular and concerned by many people. Among the most important properties of this alloy, the following can be mentioned:
- It goes from solid to liquid instead of pasty.
- It can be hammered.
- It is hard and fragile.
- Rust happens later.
- It is heat resistant.
- It comes in different types to cover a wide range of applications.
- It has a reasonable price.
- Your weight is heavy.
melting point of cast iron The melting point of cast iron is lower than the constituent elements due to the presence of impurities in pig iron and the amount of impurities that enter its composition. The melting point of cast iron is around 1420 to 1470 Kelvin. Used for its low melting point, flow, castability, machinability and wear resistance, this compound has become an engineering material for a wide range of applications. The difference between cast iron and steel The main difference between steel and cast iron is their composition. At first glance, steel and cast iron seem to be close because they are made of the same main material, called iron, and they have the same properties. Silisium is a cast iron-only material that makes a big difference between cast iron and steel. The next point is the amount of carbon used in each alloy. The percentage of carbon used in steel is less than 2%, while in cast iron this amount reaches 2% to 4%. Cast iron is also less flexible than steel. One of the most important ways to tell the difference between cast iron and steel is to perform a spark test. In this test, if the spark is low and red, the metal involved must be cast iron. But if the spark is white and long, the metal you're testing is steel. This is the method for beginners, but for professionals, there are other inspection methods such as chip testing and observation of the surface of two metals. 
cast iron flow chart
The cast iron flow chart is giving a wide range of prices and fluctuation of prices. Among its different types, cast iron offers a variety of connections, and each of them can exist and be effective in different parts of the industry depending on their connections and capabilities they have. white cast iron White cast iron is produced by accelerating the metal's cooling process and by having a lower carbon content. Therefore, most of the carbon is deposited in a semi-stable form (cementite) which increases the hardness of the cast iron. If you look at white cast iron in broken form, it is silver. White cast iron is too brittle to be used in many industries. The only place you can see it is the propeller of the windmill. White cast iron is not good, or not as good as other types of cast iron. The reason for this is its higher freezing temperature compared to other types of cast iron. White cast iron is corrosion-resistant and very affordable. gray cast iron This cast iron is called gray cast iron because it can be seen gray after crushing due to the flake graphite inside. Gray cast iron is one of the most important and widely used alloys in cast iron. There are two well-known alloys of gray cast iron, called GG-20 and GG-25, which are used in automobile manufacturing, pipe, valve and fitting manufacturing, pump manufacturing, engine body manufacturing, and parts, equipment, and industrial manufacturing. machinery. In addition to the iron element used therein, the approximate percentages of gray cast iron elements are as follows:
- Carbon: 3.5% to 4%
- Sulfur: 0.06% or less
- Silicon: 0.5 to 1.5%
- Manganese: 0.2% to 0.8%
- Phosphorus: 0.1% or less
Gray cast iron is also classified by the type of graphite used in it. These departments are as follows:
- Gray or malleable or malleable cast iron with ductile or blooming graphite.
- Gray cast iron with flake or flake graphite
- Gray or ductile iron or ductile iron with ductile iron
- Gray Bull's Eye Cast Iron; our cast iron is somewhere between gray and white. Named after the relatively large graphite in the bright scene.
Ductile iron Ductile iron is one of the new types of iron that was produced in the 20th century. Metallurgical researchers put a lot of effort into producing this cast iron and use gray cast iron compounds to make it. The production of non-brittle cast iron can be considered one of the most important events in the industry at that time. There are other names for ductile iron, such as SG iron and ductile iron, which are used in some other countries (such as the UK) instead of ductile iron. This cast iron is characterized by a spherical accumulation of graphite during solidification, which minimizes stress concentrations in the workpiece. That being said, non-brittle cast iron is a better and more complete version of gray cast iron, and it is also stronger than gray cast iron. Ductile iron is used in the pipe and automotive industries. The manufacture of crankshafts is one of the uses of this cast iron in the transport industry. The reason for this use is ductile iron's strength and good machinability. 
iron manufacturing flow chart
Iron production charts are very important in many developing countries as it contributes to the development of the country. Iron is one of the most abundant chemical elements of humans. This metal is the fourth most abundant element in the earth's crust. The production of iron includes various stages such as exploration, mining, processing, and smelting. Today, about 90% of the metals used by humans are made of iron. Iron and its alloys are used in various industries such as electronics, parts manufacturing, automobile manufacturing, and commercial and residential construction. Iron ore occurs in nature as magnetite (Fe2O4), hematite (Fe2O3), goethite (FeO(OH)), limonite (FeO(OH).n(H2O)) and siderite (FeCO3) in mineral form. Among these minerals, hematite and magnetite are more important because of their higher iron content. Hematite is red in color and has a specific gravity between 4.9 and 5.3. Magnetite is black in color and has a specific gravity of about 5.2. What is Iron Grade? The percentage of pure iron in iron ore (hematite, magnetite, etc.) is expressed in carats. Quality is considered a measure of the value of iron ore. The iron content of hematite and magnetite is about 70%. This grade indicates that there is approximately 700 kg of pure iron per 1000 kg of iron ore. NOTE: In general, a grade of 70% is generally considered a good and economical grade for iron extraction. If the value of this grade falls below 60%, iron ore mining will not be economical. What is iron ore? Iron ore is where large quantities of iron ore of acceptable quality are found. Iron ore is also called iron ore. The amount of iron ore that can be mined is called iron ore reserves. 
The ultimate reserves of iron ore in Iran are about 3 billion tons. Therefore, Iran is in the top 10 in terms of iron reserves. Iron ore can be located near the surface (up to a depth of about 1000 meters) or deep underground (up to a depth of about 2000 meters). The depth of the iron ore deposit and its shape, quality, and available equipment influence how the iron is extracted. How is iron produced? Iron ore is found in nature in the form of various minerals, such as hematite, magnetite, limonite, etc. Iron production takes place in four main stages exploration, extraction, processing, and smelting:
- Exploration: Identify where iron ore (high grade) may be present.
- Extraction: Iron ore is extracted from the ground using special equipment.
- Processing: In various physical or chemical steps, waste (low value) is separated from iron ore.
- Smelting: Transfer the processed material to a smelting furnace to obtain pure iron.
How was iron discovered? The first step in the iron production process is to find out where it is possible to locate high-quality iron ore. In this way, its mineral reserves must be discovered before iron can be extracted. There are several iron detection methods. Some of these methods are:
- geographical survey
- aerial photography
- geochemistry
- biogeochemistry
- Electric pickup
- Geophysical harvest
- drilling
There are different stages of iron ore exploration. These steps start with an initial search and continue until the final discovery. For example, geological surveys take place in the exploration phase. At this stage, geologists inspect the exposed area and check for signs indicating the presence of iron ore in the area. If approved by geologists, the next phase of exploration will proceed. In the next step, the exploration method is chosen according to the properties of the iron and the stone being explored. For example, magnetite is highly magnetic. Therefore, it can be found using geophysical methods such as magnetometry. In the final stage, to fully guarantee the iron quality and estimate the iron ore reserves, the study area is excavated and samples are tested.