The use of cast iron of different brands in different industries
Iron alloy, containing carbon, called cast iron. In some cases, alloying additives are added to the composition, affecting its consumer qualities.
Cast iron is a metal, which is used primarily in ferrous metallurgy. Not only steel is obtained from it, it is also in demand in the manufacture of forged artistic details.
Gray cast iron
Gray cast iron is mainly used for mechanical engineering, containing graphite. Details, made of such material, do not respond to emerging stresses, they absorb fluctuations, which appear in case of vibration of mechanisms.
Responsible parts are made of it:
- bushings;
- Machine frames;
- Good reasons.
As a construction material it began to be used in almost all enterprises of the machine-building industry.
Such industries have become the largest consumers of gray iron:
- automotive industry;
- machine tool construction;
- metallurgy;
- Sanitary.
Details of tractors, the material of which was gray cast iron, reach 20% from the whole number of its details. This use of this alloy is associated with high wear resistance. It does not come off in the case of high friction and lack of oil, in other words, has damping ability.
It is made of it:
- blocks;
- Bearing covers;
- Brake discs;
- Ferrado;
For the manufacture of the block head of various engines, use low-alloy alloy of the following brands:
- SCH20;
- SC25.
The main requirement, presented to the MF, in the manufacture of liners, become:
- Pearlitic structure;
- graphite;
- High hardness.
Cylinder liners are used for car engines of any design, made of a special alloy. In most cases, its phosphorus fraction is used.
Diesel engines at work create a large load on the cylinder block, therefore, they use alloyed cast iron. Cylinder heads are made of high-carbon alloy grades,
The same requirements are observed in the manufacture of sleeve castings, the material of which is a low-alloy alloy.
The chemical composition of this material depends on several technological characteristics:
- The method of melting;
- Dimensions of the casting;
- Technological form.
Cast iron camshafts are installed on cars, characterized by high wear resistance. This parameter is achieved through surface hardening, to which the metal is subjected.
When the part is operated at high speeds, when there is dry friction, it is necessary to increase the wear resistance of the material and a high coefficient of friction. It is in such conditions that this alloy is simply irreplaceable.
Brake drums, working in such conditions, made of SC20. When the part is experiencing high loads, and the possible occurrence of thermal cracks, use a special heat-resistant alloy with a high carbon content and a high level of alloying.
For particularly difficult conditions, install the details, the material of which is pearlitic cast iron. It contains vermicular graphite.
The flywheel rotates during operation 7000 about / min. This speed causes the appearance of stresses, stretching. The rotating surface of the flywheel constantly touches the working surface of another part. Such friction causes a strong release of heat resulting in thermal cracks, which adversely affect the strength of the part.
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To increase strength, given the large weight of the flywheel and the size of its cross section, it is made of different brands:
- SC25;
- CH30;
- SCH35.
It must ensure the strength of the workpiece above 250 N / mm2. Sometimes the middle 35 has strength, which is not enough to ensure the normal operation of the flywheel. In this case, use cast iron, where spherical graphite is added.
Cars boast cast iron covers, which close the main bearings. This design is found in most cases on cars with a carburetor engine. To provide a pearlitic structure, as well as high hardness, exceeding 200 NV, for the manufacture of bearing caps, apply SC25.
Manufacture of collectors
Exhaust gases act on the exhaust manifolds in the car, whose temperature reaches 90 degrees. Collectors are oxidized under the influence of aggressive environments, deform and crack.
The use of gray cast iron ensures the durability of such parts and high efficiency. Due to that, that the thickness of the collector walls is very small, Less 7 mm, for their manufacture apply SCh15. To increase its heat resistance, carry out alloying of cast iron with chromium, or nickel additives.
For the manufacture of collectors, subject to high thermal loads, use:
- Ductile iron;
- With the addition of spherical graphite;
All the above materials have high heat resistance and resistance to aggressive environments, alkalis and oxides.
Machine tool construction
A large number of cast parts are made of gray cast iron in machine tool construction, working in all sorts of conditions, the mass of which can reach 100 tons, at the maximum wall thickness 200 millimeters.
Classification of such cast parts in machine tool construction, depending on the designs, from the arisen operating conditions corresponds to the current standard.
A special brand of cast iron is selected for each part. It depends on the following parameters:
- Class blanks;
- Wall thickness;
- hardness;
- Microstructures.
Given the specifics of many machine tool parts, which work mainly on rigidity, for their manufacture it is better to use cast iron, having increased hardness, rather low plasticity.
In such cast irons, the chemical composition is high in manganese, and low carbon. To obtain high hardness of cast iron, use alloying and other technological processes.
MF blanks are widely used in metallurgical equipment:
- Rolled sheet rolls;
- molds;
- Slag bowls.
Plumbing
A lot of cast iron products are used in plumbing. Made of cast iron:
- Heating radiators;
- pipes;
- fittings;
- shells;
- Kitchen sinks.
And today cast iron baths remain in demand, which are characterized by high strength, durability and reliability. Such products can be operated for decades. They retain their original appearance and do not require replacement.
Craftsmen make artistic masterpieces from cast iron. Example, embankments of St. Petersburg, decorated with cast iron details. Walking through the streets of the city you can meet the openwork gates, original cast iron fences. Cast iron monuments can be seen in the squares.
The use of malleable cast iron
This material has excellent damping ability, it is able to work effectively at very low temperatures. This type of cast iron is used in the manufacture of critical parts of tractors, as well as cars, who will have to do their job in difficult climatic conditions.
Ductile iron parts have also found application in the electrical industry. It is made of it:
- terminals;
- Insulator hooks;
- Wire holders.
Such products perfectly cope with power loads, they can bend under mechanical impact.
In textile engineering, malleable cast iron is used in the manufacture:
- gear;
- forks
- spokes;
- Details, for paper spinning machines.
In other words, for details, under heavy static loads, subject to friction and rapid wear. Antifriction malleable cast iron is used for such products, able to create minimal friction, there, where there is a maximum contact of details.
Ductile iron is also used in plumbing products. It is made of it:
- Water taps;
- Flange adapters;
- latches;
- Heating radiators.
These products can work for a long time in the aquatic environment.
Gas systems use malleable cast iron to make fittings, connecting pipes, where there are various branches.
Various brands of ductile iron are widely used in landscaping, when the formation of decorative details:
- Original fences;
- Stalls;
- Gates;
This alloy is also used in the furniture industry, for items, which may be affected by precipitation:
- Terrace furniture;
- Gazebos.
Parts for household appliances are made of it:
- baths;
- Washing machines;
- Gas stoves;
- frying pans;
- Cauldrons.
Many car parts are made of malleable cast iron. These include:
drives;
- wheel hubs
- gears;
- crankcase;
- Engine brackets;
- Skating rinks;
- Brake pads;
- overlays;
- balancers
- Cardan shafts;
- Collectors.
Shipbuilding does not do without malleable cast iron. In the manufacture of equipment for ships, MS is used for production:
- portholes;
- Staples;
- oarlock;
- shingles;
- Water fittings.
Not forgotten ductile iron in the railway industry. When building cars, it is made of it:
- Spare parts for air brakes;
- Bearings;
- brackets
- Traction and coupling systems;
- Brackets.
Mankind has been using cast iron for many centuries, today almost everyone is dealing with such an alloy. It has high strength and relatively low cost. The only disadvantage of cast iron parts is their fragility. But, with the right technology for producing cast iron, this shortcoming is minimized, that is why cast iron parts are so widely used in the above industries.
