What are the components of gray cast iron, what are the advantages of gray cast iron, and what produ

Gray iron. The amount of carbon is higher (for, it can be seen as the matrix of carbon steel plus flake graphite. According to the different matrix structures, gray cast iron is divided into three categories: ferrite.

Matrix gray cast iron; Pearlite.

1. Ferritic matrix gray cast iron; Pearlite matrix gray cast iron.

Ferritic gray cast iron is a large and coarse graphite sheet distributed on the matrix of ferrite, which has poor strength and hardness, and is rarely used;

Pearlite gray cast iron is a uniform and fine graphite sheet distributed on the substrate of pearlite, which has relatively high strength and hardness, and is often used to manufacture important parts such as beds and bodies;

Pearlite-ferritic gray cast iron is a mixture of pearlite and ferrite on the matrix, distributed with coarse graphite sheets, although the strength and hardness of this kind of cast iron are lower than the former, but can still meet the requirements of the general body, its castability, shock absorption are good, and easy to smelt, is the most widely used gray cast iron.

The difference in the microstructure of gray cast iron is essentially the difference in the form of carbon in cast iron. The carbon in gray cast iron is composed of compound carbon (Fe3C) and graphitic carbon. When the carbon is combined, it is pearlitic gray cast iron; When the chemical carbon is less than that, it belongs to pearlite-ferritic gray cast iron; When all carbon is in the graphite state, it is ferritic gray cast iron.

The carbon in the gray cast iron is mainly crystallized into graphite and is present in the cast iron in a sheet form, with a dark gray fracture. The chemical composition of gray cast iron is generally as follows: ,,,s.

Gray iron. It is a heat transfer coefficient similar to that of a sand mold or a sand mold.

The casting mold is cast, and there are gray particles at the first mouth of the broken trouble, so it is called gray cast iron. Grey cast iron has good casting properties, machinability, high wear resistance, vibration damping and low notch sensitivity.

Due to the high carbon content, rough structure, tensile strength.

It is not high, but it has good brittleness, but excellent compressive performance. The grade of gray iron is indicated by HT plus tensile strength grade. There are 6 grades of gray iron casting:.

It has a certain tensile strength. It has good wear resistance, vibration resistance and ease of processing, and can maintain high accuracy after aging or heat treatment. It is mostly used in mechanical parts, such as machine tool bases, cast iron platform plates, hydraulic pistons, plastic crushing mechanisms, pulleys, etc.

Quansheng casts gray iron castings, and the iron casting process includes lost foam, sand mold and precision casting. Follow the drawings provided by the customer. At the same time, Kwon Seong has 16 years of experience and technology in casting.

Therefore, it brings a different experience from other manufacturers to a wide range of customer groups. Professional after-sales team, imitation bending Qing to ensure the follow-up problems that customers are prepared for. (Look).

Gray cast iron is a common kind of iron casting, also called gray cast iron or ordinary cast iron.

The carbon content of the pre-gray cast iron is greater than that of flake graphite.

Gray cast iron code such as HT20-40, the front data is tensile strength, the back data is the chain bending strength.

Gray cast iron has good wear resistance, shock absorption, good casting and molding properties, and machinability.

With the above various properties, it is convenient to manufacture a large number of various products.

All kinds of boxes, sheds such as support seats, machine tool bodies, discs, sets of medium-load parts, etc.

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(1) Mechanical properties.

The structure of gray cast iron is equivalent to steel as a matrix with the addition of flake graphite. The matrix contains more silicon, manganese and other elements than steel, and these elements can be dissolved into the ferrite to strengthen the matrix, so the strength and hardness of the matrix are not lower than the corresponding steel. The strength, plasticity and toughness of flake graphite are almost zero, which can be approximated as some microcracks, which not only cut the continuity of the matrix structure and reduce the effective cross-section of the matrix under load, but also is easy to produce stress concentration at the tip of graphite, and is easy to produce brittle fracture when the iron casting is subjected to tensile force or impact force.

Therefore, the tensile strength, fatigue strength, plasticity and toughness of gray cast iron are much lower than those of steel with the same matrix. The greater the number of graphite sheets, the coarser the graphite sheets, the more uneven the distribution, the more serious the fragmentation effect and stress concentration on the matrix, the lower the tensile strength, fatigue strength, plasticity and toughness.

The properties of gray cast iron depend mainly on the structure of the matrix and the quantity, shape, size and distribution of graphite. Since the compressive strength, hardness and wear resistance of gray cast iron mainly depend on the matrix, the presence of graphite has little effect on it, therefore, the compressive strength and hardness of gray cast iron are similar to those of steel with the same matrix. The compressive strength of gray cast iron is generally 3 4 times its tensile strength.

2) Other performance.

Although graphite reduces the tensile strength, plasticity and toughness of gray cast iron, it is precisely because of the presence of graphite that cast iron has a series of other excellent properties.

1) Excellent casting performance. Gray cast iron has a low melting point, good fluidity during casting, small shrinkage, and is not easy to appear shrinkage porosity and shrinkage porosity during the casting process, so gray cast iron can be poured out of thin-walled parts with complex shapes.

2) Good vibration damping performance. The graphite in gray cast iron can act as a buffer for vibration, prevent vibration propagation, and convert vibration energy into heat energy, so cast iron has good vibration damping (the vibration damping capacity of cast iron is about 10 times greater than steel), and is often used for parts such as machine tool bases, frames, fuselages and boxes that withstand pressure and vibration.

3) Good anti-friction performance. Graphite itself is a good lubricant, and the pores left after graphite peeling during use have the effect of adsorbing and storing part of the lubricating oil, so that the oil film on the friction surface is easy to maintain and has good friction reduction. Therefore, the parts such as machine tool rails and cylinder blocks that are subjected to friction can be made of gray cast iron.

4) Good machinability. Because graphite cuts the continuity of the matrix structure, it is easy to break and remove chips during the cutting process, and graphite has a certain lubricating effect on the tool, so that the tool wear is reduced.

5) Lower notch sensitivity. The graphite in the cast iron is equivalent to the existence of many tiny cracks in the cast iron, thus weakening the effect of the external gap on the cast iron.

Gray cast iron is cast iron with flake graphite on the middle finger, and it is called gray cast iron because the fracture is dark gray when broken. The main components are iron, carbon, silicon, manganese, sulfur and phosphorus, which is the most widely used cast iron, and its output accounts for more than 80% of the total cast iron output. According to the morphology of graphite, gray cast iron can be divided into:

Plain gray cast iron, graphite in flakes; ductile iron, graphite is spherical; Malleable cast iron, graphite in clump flocculent; Graphite cast iron, graphite is worm-like.

Gray cast iron is a type of cast iron. Carbon is found in cast iron in the form of flake graphite. The fracture is gray.

It has good cutting performance and good wear resistance. It is used in the manufacture of racks, cabinets, etc. Gray cast iron graphite is flake-like, the effective bearing area is relatively small, and the tip of graphite is easy to produce stress concentration, so the strength, plasticity and toughness of gray cast iron are lower than those of other cast irons.

However, it has excellent vibration damping, low notch sensitivity and high wear resistance.

1. Gray cast iron has low density and mechanical properties. The tensile strength of gray cast iron is relatively low, this phenomenon is inseparable from the microstructure characteristics of gray cast iron, because the mechanical properties of graphite are very low, therefore, the microstructure of gray cast iron is equivalent to steel full of holes or cracks on the town. During tensile, due to the segmentation effect of flake graphite on the steel matrix and the stress concentration effect caused by it, its anti-wear sail tensile strength value is much lower than that of steel.

2. Excellent wear resistance and shock absorption. Because the graphite in cast iron is good for lubrication and oil storage, it has good wear resistance. Similarly, due to the presence of graphite, gray cast iron has better shock absorption than steel.

3. Good process performance. Due to the high carbon content of gray cast iron and close to eutectic composition, the melting point is lower than that of steel, so the casting fluidity is good. In addition, since graphite makes it easy to form chips during cutting, the machinability of gray cast iron is better than that of steel.

Summary. Hello dear, I am honored to answer for you: pig iron is an iron-carbon alloy with a carbon content greater than 2, and the carbon content of industrial pig iron is generally 2%, and contains C, SI, MN, S, P and other elements, which is a product smelted by blast furnace with iron ore.

What kind of pig iron is used for gray iron 250 castings? What is the chemical composition of pig iron?

Hello dear, I am honored to answer for you: pig iron is more than 2 carbon-containing iron and carbon hail gold, industrial pig iron carbon content is generally 2%, and contains C, SI, MN, S, P and other elements, is the product smelted with iron ore by Gao Jingyun furnace.

Pig iron properties: pig iron is hard, wear-resistant, and has good castability, but pig iron is brittle and cannot be forged.