Ductile iron - material underestimated in power? | Power engineering and industry online
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So far, the use of ductile iron fittings in the water industry and not only became widespread enough that one already steam tables it's not surprising. But the valve can be safely used at higher performance in power plants? So far, its use in systems for medium and higher performance raised many doubts. Are they right?
The main reason for the resistance against the use of ductile iron fittings is inherent in the name of material, the term "cast iron". Intuitively, mistakenly connected to the properties of ductile iron, gray iron casting defects (fragility) and not cast steel, which seems more reasonable. Ductile iron is just as flexible as steel or ductile cast. Virtually all fittings factories are now producing industrial valves made of cast iron.
By the definition of encyclopedic cast alloy is iron (chemical element) with carbon (and other less important components) with a carbon content of from 2.5 to 4.5%. Cast iron melts at a relatively low temperature of approx. 1300 C. This allows you to prepare in a simple and inexpensive liquid iron in furnaces for melting in the so-called. cupolas. Cast well and accurately filled molds allowing you to perform precision castings. Cast iron can exist in two forms essential: a white cast iron. In this embodiment, the carbon is present as cementite (iron carbide). Breakthrough of the iron is light, almost white. Hence its name. It has high mechanical strength, but it is very hard. Due to this property (hardness) can not be processed by conventional methods of mechanical steam tables processing (chip). There is only a rough example. For the production of so-called elements. malleable. as cast iron. In this embodiment, the carbon is separated in the form of flake graphite, pure carbon black. This breakthrough is gray cast iron, as is graphite steam tables gray. It has good mechanical strength, but the tensile breaking suddenly without notice (without extension). Plane cracks always run along the graphite flakes, which tend to be so large that sometimes are visible to the naked eye at the turn. Cast iron has good casting molds, giving a clean surface, it is easy to be common machining tools.
Graphite has a very low strength and low modulus of elasticity, which is the cause of the discontinuity in the elastic metallic matrix. Therefore, cast iron has good vibration reduction. This advantage is used in the construction of the machine frame. The more graphite in the matrix steam tables and the greater are the cereals, including the ability to dampen vibration is improved. However, graphite Grubopłatkowy causes significant weakening steam tables of the metal matrix and is the cause of low strength.
To reduce the disadvantages of iron, which is caused by the presence of the fragility of flake graphite has long sought methods for removing the graphite. This resulted, even at the beginning of last year. Ductile iron age in which graphite is either burned or shredded. All these methods are based on long-term annealing, finished castings cast under various conditions (thermal treatment). For a long time it was the primary method of making fine cast iron components, eg. For the automotive industry and small couplings, elbows, tees pipeline. One feature of the malleable is the possibility of galvanizing. Cast iron can not be hot-dip zinc. Adopted in Polish name malleable is a little misleading. In other countries have adopted steam tables the names involved in the process, such as "thermally processed". Eg. In German steam tables using the designation "Temperguss".
In the 50s last year. Century, developed the method of casting, which managed to get the structure of cast iron with graphite flakes divided cast directly without any additional heat treatment. There were many patented methods for producing steam tables such a cast. It is called the modified cast iron or cast iron drobnopłatkowym. Fragmentation of graphite flakes very positive effect on the mechanical properties. These iron gain considerable flexibility, decreases their fragility, fragile breakthrough steam tables threat disappears. In the 70s modification went so far that the graphite was evolved in the form of small balls, spheres. Significantly improved properties - to the extent that this material was isolated as a separate group of ductile iron.
The name "ductile" took place in Poland because, steam tables to distinguish it from malleable. Also in most other languages accepted this principle. In Germany it is Duktiles Gusseisen = malleable, el
Home About us About the Council's steam tables Program Sponsorships They trust us Media Advertising Offers Companies Energopomiar Sp. z oo Hydro-Pomp Sp. z oo National Centre for Nuclear Research Contact Rockwool Technical steam tables Insulation
So far, the use of ductile iron fittings in the water industry and not only became widespread enough that one already steam tables it's not surprising. But the valve can be safely used at higher performance in power plants? So far, its use in systems for medium and higher performance raised many doubts. Are they right?
The main reason for the resistance against the use of ductile iron fittings is inherent in the name of material, the term "cast iron". Intuitively, mistakenly connected to the properties of ductile iron, gray iron casting defects (fragility) and not cast steel, which seems more reasonable. Ductile iron is just as flexible as steel or ductile cast. Virtually all fittings factories are now producing industrial valves made of cast iron.
By the definition of encyclopedic cast alloy is iron (chemical element) with carbon (and other less important components) with a carbon content of from 2.5 to 4.5%. Cast iron melts at a relatively low temperature of approx. 1300 C. This allows you to prepare in a simple and inexpensive liquid iron in furnaces for melting in the so-called. cupolas. Cast well and accurately filled molds allowing you to perform precision castings. Cast iron can exist in two forms essential: a white cast iron. In this embodiment, the carbon is present as cementite (iron carbide). Breakthrough of the iron is light, almost white. Hence its name. It has high mechanical strength, but it is very hard. Due to this property (hardness) can not be processed by conventional methods of mechanical steam tables processing (chip). There is only a rough example. For the production of so-called elements. malleable. as cast iron. In this embodiment, the carbon is separated in the form of flake graphite, pure carbon black. This breakthrough is gray cast iron, as is graphite steam tables gray. It has good mechanical strength, but the tensile breaking suddenly without notice (without extension). Plane cracks always run along the graphite flakes, which tend to be so large that sometimes are visible to the naked eye at the turn. Cast iron has good casting molds, giving a clean surface, it is easy to be common machining tools.
Graphite has a very low strength and low modulus of elasticity, which is the cause of the discontinuity in the elastic metallic matrix. Therefore, cast iron has good vibration reduction. This advantage is used in the construction of the machine frame. The more graphite in the matrix steam tables and the greater are the cereals, including the ability to dampen vibration is improved. However, graphite Grubopłatkowy causes significant weakening steam tables of the metal matrix and is the cause of low strength.
To reduce the disadvantages of iron, which is caused by the presence of the fragility of flake graphite has long sought methods for removing the graphite. This resulted, even at the beginning of last year. Ductile iron age in which graphite is either burned or shredded. All these methods are based on long-term annealing, finished castings cast under various conditions (thermal treatment). For a long time it was the primary method of making fine cast iron components, eg. For the automotive industry and small couplings, elbows, tees pipeline. One feature of the malleable is the possibility of galvanizing. Cast iron can not be hot-dip zinc. Adopted in Polish name malleable is a little misleading. In other countries have adopted steam tables the names involved in the process, such as "thermally processed". Eg. In German steam tables using the designation "Temperguss".
In the 50s last year. Century, developed the method of casting, which managed to get the structure of cast iron with graphite flakes divided cast directly without any additional heat treatment. There were many patented methods for producing steam tables such a cast. It is called the modified cast iron or cast iron drobnopłatkowym. Fragmentation of graphite flakes very positive effect on the mechanical properties. These iron gain considerable flexibility, decreases their fragility, fragile breakthrough steam tables threat disappears. In the 70s modification went so far that the graphite was evolved in the form of small balls, spheres. Significantly improved properties - to the extent that this material was isolated as a separate group of ductile iron.
The name "ductile" took place in Poland because, steam tables to distinguish it from malleable. Also in most other languages accepted this principle. In Germany it is Duktiles Gusseisen = malleable, el
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