Xiamen imported QT400-18 ductile iron price

Xiamen imported ductile iron price imported ductile iron rods imported ductile iron plates imported ductile iron square rods Japan imported ductile iron rods Japan imported ductile iron plates high wear-resistant ductile iron rods high temperature resistant ductile iron plates high strength ductile iron rods large diameter ductile iron round rods Gray cast iron rod, gray cast iron round rod, imported gray cast iron plate, corrosion-resistant ductile iron, comparison table of ductile iron grades in different countries, Xiangyun ductile iron wholesale, imported ductile iron, imported gray cast iron, imported gray cast iron, baseball graphite cast iron material certificate, ductile iron chemical composition, ductile iron price, gray cast iron price Dongguan Xiangyun Ductile Iron Ductile Iron
A general name for alloys mainly composed of iron, carbon and silicon. In these alloys, the carbon content exceeds the amount that can be retained in the austenite solid solution at the eutectic temperature. Cast iron is a general term for alloys mainly composed of iron, carbon and silicon. In these alloys, the carbon content exceeds the amount that can be retained in the austenite solid solution at the eutectic temperature.
Iron-carbon alloys with carbon content above. Industrial cast iron generally has a carbon content of ~. Carbon mostly exists in the form of graphite in cast iron, and sometimes in the form of cementite. In addition to carbon, cast iron also contains silicon, manganese, phosphorus, sulfur and other elements. Alloy cast iron also contains elements such as nickel, chromium, molybdenum, aluminum, copper, boron and vanadium. Carbon silicon is the main element affecting the microstructure and properties of cast iron.
Cast iron can be divided into
① Gray cast iron. It has a high carbon content (~carbon mainly exists in the form of flake graphite, and the fracture surface is gray, referred to as gray iron. It has a low melting point (~℃) and small shrinkage when solidified. Its compressive strength and hardness are close to carbon steel, and it has good shock absorption. Used to manufacture machine tool beds, cylinder boxes and other structural parts.
② White cast iron. The carbon silicon content is low, the carbon mainly exists in the form of cementite, and the fracture surface is silvery white. It shrinks greatly during solidification and is prone to shrinkage. Hole cracks. High hardness, high brittleness, cannot withstand impact loads. Mostly used as blanks of malleable cast iron and to make wear-resistant parts.
③ Malleable cast iron. Obtained from white cast iron after annealing, graphite is in the form of floccules Distribution, referred to as tough iron. Its structural properties are uniform, wear-resistant, and has good plasticity and toughness. It is used to manufacture parts with complex shapes that can withstand strong dynamic loads.
④ Ductile iron. The gray cast iron molten iron is passed through the ball Obtained after chemical treatment, the precipitated graphite is spherical, referred to as ductile iron. It has higher strength, better toughness and plasticity than ordinary gray cast iron. It is used to manufacture internal combustion engine automobile parts and agricultural machinery and tools.
⑤ Vermicular graphite cast iron . It is obtained by vermigating gray cast iron molten iron, and the precipitated graphite is in the shape of worms. The mechanical properties are similar to that of ductile iron, and the casting performance is between gray cast iron and ductile iron. It is used to manufacture automobile parts.
⑥Alloy cast iron. Ordinary cast iron is obtained by adding an appropriate amount of alloying elements (such as silicon, manganese, phosphorus, nickel, chromium, molybdenum, copper, aluminum, boron, vanadium, tin, etc.). The alloying elements change the matrix structure of the cast iron, thus having corresponding heat resistance, wear resistance, corrosion resistance, etc. Low temperature or non-magnetic properties. Used for manufacturing parts of mining chemical machinery and instrumentation.
Classification of cast iron
Classification method Classification name description
Fracture color classification
Gray cast iron Most or all of the carbon in this kind of cast iron is in the form of free flake graphite. Its fracture surface is dark gray, has certain mechanical properties and good cutting performance, and is widely used in industry
White cast iron White cast iron is an iron-carbon alloy with no or almost no graphite in the structure. Its fracture surface is bright white, hard and brittle, and cannot be cut. It is rarely used directly in industry to make mechanical parts. It has Very high surface hardness and wear resistance, also known as chilled cast iron or chilled cast iron
Mock-kou cast iron Mock-kou cast iron is a kind of cast iron between white cast iron and gray cast iron, and its fracture is gray and white. Pockmarked, poor performance, rarely used
Chemical composition
Ordinary cast iron refers to cast iron that does not contain any alloying elements, such as gray cast iron, malleable cast iron, ductile iron, etc.
Alloy cast iron is A high-grade cast iron prepared by adding some alloying elements to ordinary cast iron to improve certain special properties. Such as various special performance cast irons that are corrosion-resistant, heat-resistant, and wear-resistant
Production methods and structural properties
Ordinary gray cast iron, see gray cast iron
Inoculation cast iron is based on gray cast iron and is made of modified material, also known as modified cast iron. Its strength, plasticity and toughness are much better than ordinary gray cast iron, and its structure is more uniform. Mainly used to manufacture large castings that require high mechanical properties and large changes in cross-sectional dimensions
Malleable cast iron Malleable cast iron is made of white cast iron with a certain composition and graphitized annealing. It has higher toughness than gray cast iron and is Called ductile cast iron. It cannot be forged and is often used to make castings that can withstand impact loads
Ductile iron is referred to as ductile iron. It is obtained by adding a certain amount of nodularizing agent and inking agent to the molten iron before casting to promote the crystallization of spheroidal graphite. Compared with steel, except for its slightly lower plastic toughness, its other properties are similar. It is an excellent material that has the advantages of both steel and cast iron. It is widely used in mechanical engineering
Special performance cast iron This is a kind of cast iron with certain characteristics Cast iron, according to different uses, can be divided into wear-resistant cast iron, heat-resistant cast iron, corrosion-resistant cast iron, etc. Most of them belong to alloy cast iron and are widely used in machinery manufacturing
Cast iron heat treatment process
Stress relief annealing Due to the uneven wall thickness of the casting, effective stress and structural stress will be generated during the heating, cooling and phase transformation processes. . In addition, large parts are prone to residual stress after machining, and all these internal stresses must be eliminated. The usual heating temperature for stress relief annealing is ~℃ and the holding time is ~, and then furnace cooling (gray iron) or air cooling (ductile iron). Using this process can eliminate the internal stress of the casting, but the cast iron structure will not change. If the temperature exceeds ℃ or the holding time is too long, it will cause graphitization and reduce the strength and hardness of the casting.
High-temperature graphitization annealing to remove cast iron white spots
When castings are cooled, white spots often occur on the surface layer and thin sections. The white structure is hard and brittle and has poor processing performance and is easy to peel off. Therefore, annealing (or normalizing) must be used to eliminate the white structure. The annealing process is to heat to ℃ and keep warm, then cool the furnace to ℃ and then leave the furnace for air cooling. During the high-temperature insulation period, free cementite and eutectic cementite decompose into graphite and graphite. During the subsequent cooling process, secondary cementite and eutectoid cementite also decompose, and the graphitization process occurs. Due to the decomposition of cementite, the hardness decreases, thereby improving the machinability.
Normalizing Iron
The purpose of normalizing ductile iron is to obtain the pearlite matrix structure, refine the grains, and uniform the structure to improve the mechanical properties of the casting. Sometimes normalizing is also a structural preparation for surface quenching of ductile iron. Normalizing is divided into high-temperature normalizing and low-temperature normalizing. The high-temperature normalizing temperature generally does not exceed ~℃, and the low-temperature normalizing temperature is generally heated to the refractory temperature range ~℃. After normalizing, four people are generally required to handle it to eliminate the internal stress generated during normalizing.
Quenching and tempering of iron
In order to improve the mechanical properties of ductile iron, castings are generally heated to above ~°C (representing the final temperature formed during heating) and then quenched in oil to obtain a martensite structure. In order to Appropriately reduce the residual stress after quenching. Generally, tempering should be performed after quenching. The low-temperature tempered structure is tempered martensite plus residual bainite plus spherical graphite. This structure has good wear resistance and is used for applications requiring high wear resistance. High-strength parts. The medium-temperature tempering temperature is ℃. The structure after tempering is tempered troostite plus spherical graphite. It is suitable for thick parts that require good wear resistance and a certain degree of stability and elasticity. Related talents of Xiangyun Company More concentrated in the Steel Talent Network. The high temperature tempering temperature is ℃, and the structure after tempering is tempered Soxhlet plus spherical graphite. The one with good combination of toughness and strength is ℃. The structure after tempering is tempered Soxhlet plus spherical graphite. Spherical graphite has a good combination of toughness and strength, so it is widely used in production.
Multi-temperature quenching of iron
Ductile iron can obtain high strength after isothermal quenching, and at the same time it has good Plasticity and toughness. The selection of heating temperature for multi-temperature quenching is mainly to ensure that the original structure is completely transformed without remaining, and at the same time to avoid grain growth. The heating temperature is generally above ~℃, and the isothermal treatment temperature is ~℃ to ensure that comprehensive mechanical properties are obtained Lower bainite structure. After isothermal quenching of rare earth magnesium aluminum ductile iron~,~,~. However, it should be noted that a tempering process is added after isothermal quenching.
Surface quenching
In order to improve the quality of some castings For surface hardness, wear resistance and fatigue strength, surface quenching can be used. Both gray cast iron and ductile iron castings can be surface quenched. Generally, high (medium) frequency induction heating surface quenching and electrical contact surface quenching are used.
Learn heat treatment< br/> For castings that require surface wear resistance or oxidation and corrosion resistance, chemical heat treatment processes similar to steel can be used, such as gas soft chlorination, chlorination, boronization, sulfurization, etc.
Gray cast iron
China
Japan
South Korea
United States
United States
Ductile Iron
China
Japan
South Korea
United States
United States
Features Product specifications are complete, price is favorable, packaging is intact, copper is pure, straightness is good, inventory is large, material certificates and reports can be provided.
Specifications can be customized, Xiangyun Company welcomes your Call us and we will sincerely serve you. [Sales hotline Manager Liu
][
][
]
Beijing ductile iron rod Tianjin ductile iron rod Hebei ductile iron rod Shanxi ductile iron rod Cast iron rod
Inner Mongolia ductile iron rod Hainan ductile iron rod Liaoning ductile iron rod Jilin ductile iron rod
Heilongjiang ductile iron rod Shanghai ductile iron rod Jiangsu ductile iron rod Chongqing ductile iron rod
Zhejiang ductile iron rod Anhui ductile iron rod Fujian ductile iron rod Jiangxi ductile iron rod Shandong ductile iron rod Sichuan ductile iron rod Henan ductile iron rod Hubei ductile iron rod
Hunan ductile iron rod Guangdong ductile iron rod Guangxi ductile iron rod Guizhou ductile iron rod
/>Yunnan ductile iron rod Tibet ductile iron rod Shaanxi ductile iron rod Gansu ductile iron rod
Qinghai ductile iron rod Ningxia ductile iron rod Xinjiang ductile iron rod Hong Kong ductile iron rod
Macau ductile iron rod Taiwan ductile iron rod Other ductile iron rods