KR100892320B1 - Overlay welding layer and pulverizer - Google Patents

Abstract

A multi-overlay welding layer with superior abrasion resistance and a crusher roll and a rotational plate of a pulverizer using the same are provided to repress the abrasion of overlay welding layer formed on the crusher roll or rotational plate. A multi-overlay welding layer with superior abrasion resistance comprises a base layer(2a,2b,2c,2d) and a hardening layer having hardness greater than that of the base layer. The base layer contains, in weight%, C: 4.2~5.0%, Si: 0.5~1.5%, Mn: 0.5~1.4%, Cr: 23.0~25.0%, Mo: 0.5~1.0%, and the rest Fe and inevitable impurities. The hardening layer contains, in weight%, C: 4.5~6.0%, Si: 0.6~2.5%, Mn: 0.1~2.0%, Cr: 22.0~26.0%, Mo: 4.5~6.0%, Nb: 2.5~4.5, V: 0.5~2.0%, W: 4.0~10.0%, and the rest Fe and inevitable impurities. In the overlay welding layer, check cracks are formed into multilayer.

Description

Multi-layered welding layer with excellent wear resistance and grinding roll and rotating plate of fine grinding using the same {overlay welding layer and pulverizer}

The present invention relates to a growth welding layer and a pulverized grinding roll and a pulverized rotating plate using the same for improving wear resistance and increasing the service life to reduce productivity and production cost.

In the cement plant or power plant, the mechanical part of the mill that grinds the raw materials is a circular or conical roll which is in physical contact with the milled matter to granulate the milled matter, and the roll unit is driven on the milling plate by the drive unit of the mill. By the rotational movement, the grinding process between the outer edge of the roll and the pulverized object provided on the rotating plate proceeds. Rolls and rotating plates are generally composed of structural steel, which is relatively abrasion resistant, but even in such a case, a part of the outer edge may drop out when used for a certain period of time.

Conventionally, when the grinding roll and the rotating plate are worn out, they are replaced with new products or subjected to maintenance welding. At this time, the grinding mill must be stopped to perform replacement or maintenance welding, and the physical properties for replacement This results in a lot of time and money, so a longer service life saves time and money.

The conventional repairing method is to perform a primary welding of about 10 mm in thickness by using a base material and a well-welded welding material to facilitate welding on the base material according to the characteristics of the base materials 1a, 1b, 1c, and 1d. It is used for the welding welding using the growth welding material or the welding welding up to the design dimension using the normal high hardness growth welding material directly on the base material.

However, the conventional welding layer does not have excellent wear resistance, and when used in a mill for a power plant, the service life up to a limited dimension is about 20,000 hours. Therefore, the grinding roll and the rotating plate of the mill of the power plant are replaced every two years. Therefore, there is a need for a growth welding layer method capable of simultaneously reducing the maintenance period and reducing the cost by using the grinding roll and the rotating plate of the grinding mill for more than 30,000 hours.

The present invention is a growth welding layer and check crack shape having a component composition with excellent wear resistance to solve the frequent maintenance due to the severe wear of the growth welding layer formed on the grinding roll or the rotating plate of the grinding mill or the rotating plate which is a problem of the prior art It relates to a multi-layer growth welding to have a grinding roll and a rotating plate comprising the same.

The present invention is a multi-layer growth welding layer formed on the surface layer of the base material of spherical graphite cast iron or cast steel, the multi-layer growth welding layer is a hardness greater than the hardness of the base layer and the base layer having a hardness greater than the hardness of the base material Consists of a cured layer having a, the base layer by weight, C: 4.2 ~ 5.0%, Si: 0.5 ~ 1.5%, Mn: 0.5 ~ 1.4%, Cr: 23.0 ~ 25.0%, Mo: 0.5 ~ 1.0% , The remaining Fe and other unavoidable impurities, the hardened layer in weight%, C: 4.5 ~ 6.0%, Si: 0.6 ~ 2.5%, Mn: 0.1 ~ 2.0%, Cr: 22.0 ~ 26.0%, Mo: 4.5 ~ 6.0%, Nb: 2.5 ~ 4.5, V: 0.5 ~ 2.0%, W: 4.0 ~ 10.0%, remaining Fe and other unavoidable impurities, and a series of check cracks are formed in multiple layers in succession to form bricks intertwined and intertwined It is formed in a state, the check crack is excellent in wear resistance, characterized in that the horizontal and vertical size of 5 to 20 mm and the weld layer thickness of the entire hardened layer is 5 to 40 mm, respectively It provides a multilayer growth welding layer.
The present invention also provides a multi-layered welding layer in which a base layer having a hardness greater than that of the base material and a cured layer having a hardness greater than the hardness of the base layer are sequentially grown and welded on a base material made of spherical graphite cast iron or cast steel. The base layer is in weight percent, C: 4.2-5.0%, Si: 0.5-1.5%, Mn: 0.5-1.4%, Cr: 23.0-25.0%, Mo: 0.5-1.0%, remaining Fe and It is composed of other unavoidable impurities, the cured layer is by weight, C: 4.5 ~ 6.0%, Si: 0.6 ~ 2.5%, Mn: 0.1 ~ 2.0%, Cr: 22.0 ~ 26.0%, Mo: 4.5 ~ 6.0%, Nb: 2.5 ~ 4.5, V: 0.5 ~ 2.0%, W: 4.0 ~ 10.0%, the remaining Fe and other unavoidable impurities, and the multi-layered welding layer is formed by forming a multilayer of check cracks in succession to form bricks intertwined with each other. It is formed in a woven structure, wherein the check cracks are 5 to 20 mm in width and length, respectively, and 5 to 40 mm in total thickness of the hardened layer, and are heavily rubbed in areas of high wear. Cured layer is a cured layer of the small wear amount forming the thickness and the friction deolhae portion provides a superior differentiator break rolls and rotating plate wear resistance, characterized in that the grown welding to form a reduced thickness.

The grinding mill and the rotating plate including the multi-layer growth welding layer of the present invention have excellent wear resistance, so that the service life is lengthened as the service life is greatly extended, thereby improving productivity and reducing costs.

The multilayer growth welding layer grown and welded on a base material made of spherical graphite iron or cast steel of the present invention comprises a base layer (2a, 2b, 2c, 2d) and a hardened layer (3a, 3b, 3c, 3d). The composition of (2a, 2b, 2c, 2d) is in weight%, C: 4.2-5.0%, Si: 0.5-1.5%, Mn: 0.5-1.4%, Cr: 23.0-25.0%, Mo: 0.5- 1.0%, the remaining Fe and other unavoidable impurities, the composition of the cured layer (3a, 3b, 3c, 3d) by weight, C: 4.5 ~ 6.0%, Si: 0.6 ~ 2.5%, Mn: It consists of 0.1 to 2.0%, Cr: 22.0 to 26.0%, Mo: 4.5 to 6.0%, Nb: 2.5 to 4.5, V: 0.5 to 2.0%, W: 4.0 to 10.0%, and the remaining Fe and other unavoidable impurities.

The cured layers 3a, 3b, 3c, and 3d of the present invention should be excellent in weldability and wear resistance by welding to the upper layers of the base layers 2a, 2b, 2c, and 2d. Tungsten carbide and high carbon niobium carbide alloy steels are used.

Next, the reason for numerical limitation of each component composition formed by cemented carbide welding will be described in detail.

C is preferably 4.5 to 6.0% by weight, which is added at a level higher than the existing high carbon steel to form tungsten carbide and niobium carbide in the deposited metal to obtain high hardness, and excessive precipitation of carbide causes chromium depletion. Since brittleness is strong, it is preferable to limit the content to 6.0% or less. In addition, when the carbon content is 4.5% or less, tungsten carbide and niobium carbide required cannot be obtained.

Si is preferably 0.6 to 2.5% by weight.Si is used for the purpose of preventing deoxidation and impurity, so it should be added more than 0.6% .When a large amount is added, abrasion resistance is reduced by coarsening of peroxide and metal particles. It is preferable to limit.

Mn is preferably 0.1 to 2.0% by weight, and Mn is an essential element to stabilize the austenite phase and is added to stabilize a large amount of carbide. However, when a large amount is added, brittleness due to work hardening is excessively increased, so the content is preferably limited to 0.1 to 2.0%.

Cr is preferably 22.0 to 26.0% by weight. Cr is a component that is added to improve the strength and abrasion resistance by generating carbide on the stabilized martensite. When the Cr content is 22.0% or less, the wear resistance is reduced due to unstable martensite structure formation. If it is 26.0% or more, it is preferable to limit the brittleness to 22.0 to 26.0% because brittleness is strong and the welding state is unstable.

Mo is preferably 4.5 to 6.0% by weight. Mo is generally added in an amount of 1% or less for the purpose of increasing the elastic limit and increasing the abrasion resistance while preventing the brittleness. In the high carbon alloy steel of the present invention, a large amount of carbide is formed. And double welding of the superhard alloy layer on the high hardness alloy layer, resulting in strong temper brittleness after welding, minimizing this, stabilizing carbides, and adding up to 6.0% for the purpose of improving the strength by dispersing the matrix structure. If the content is less than 4.5%, strength and toughness are reduced due to the generation of temper brittleness after welding.

Nb is preferably 2.5 to 4.5% by weight, and Nb is added for the purpose of forming carbides on the base metal to improve hardness and wear resistance. Added at ˜4.5%.

V is preferably 0.5 to 2.0% by weight, V is added to increase the toughness and wear resistance in the present invention was added at 0.5 to 2.0%.

W is preferably in the range of 4.0 to 10.0% by weight. W is added for the purpose of forming carbides in the base metal to improve high temperature hardness and wear resistance at high temperature. In particular, when the tungsten carbide and niobium carbide-based high carbon alloy steels are welded and formed into the hardened layers 3a, 3b, 3c, and 3d, the conventional growth welding layer is irrespective of the type of the base materials 1a, 1b, 1c, and 1d. The service life can be extended by 50% of the service life of the.

Multi-layer fusing welding layer of the present invention is a check crack width (X) and check crack vertical size (Y) made of 5 to 20 mm each made of bricks stacked to form a check state (Brick Structure For Stringer Bead) It has a shape of Check Crack, and the hardened layer thickness Z which is the whole thickness of the hardened layer welded by the multilayer is formed in 5-40 mm.

If the thickness is less than 5mm when the welding and the dilution of the primary welding component due to the dilution of the secondary welding welder performance, and when more than 40mm in the case of multi-layer welding does not solve the stress can be peeled off due to poor welding. .

In the case of multi-layer welding, the check crack should be welded in the size of 5 ~ 20㎜ in a predictable crack state to induce the occurrence of stress in the expected direction during welding in order to remove the stress due to welding heat and residual stress. . In this continuous multi-layer welding, the molten molton of the weld is penetrated between the cracks generated first, so that the cracks are staggered, and the layers are stacked. Even if the maximum weld thickness is advanced to 90 mm, the crack or total rupture phenomenon occurs in the cross check crack. And the phenomenon of biting of the welded site does not occur. If the check crack is out of the range, multi-layer welding is impossible, and after the welding, stress relief does not occur in the weld metal, so that the phenomenon or the occurrence of the base material (1a, 1b, 1c, 1d) or the base material (1a, 1b, 1c, 1d) the rupture phenomenon of the whole cracking occurs, which leads to a problem of shortening the service life by increasing the amount of wear.

The growth welding layer manufacturing method of the present invention comprises the steps of preheating the base material; A base layer welding step; It consists of a hardened layer welding step, the preheating of the base material is preheated at a preheating temperature of 170 ℃ ± 30 ℃, the base layer welding step and the hardened layer welding step is the interlayer temperature which is the temperature of the previous welding layer immediately before welding Is characterized in that 140 ~ 200 ℃.

The purpose of the preheating of the present invention is to reduce the heat loss and slow down the cooling rate of the weld to reduce the degree of hardening of the material, to suppress segregation of impurities that may cause cracking, to reduce the amount of thermal deformation due to welding, It facilitates the release, suppresses the occurrence of cracks due to hydrogen such as hydrogen embrittlement, prevents the incorporation of hydrogen in the weld metal, and facilitates welding of the weld metal.

The preheating temperature of the present invention is most preferably 170 ℃ ± 30 ℃, if the temperature is too high, excessive heat input causes a decrease in strength and impact, if the temperature is too low, the cooling rate of the weld due to heat loss during welding is faster The hardening of the base material (1a, 1b, 1c, 1d) may occur, which may cause cracking after welding, and the welding state becomes poor, so the above preheating temperature range should be observed.

The interlayer temperature of the present invention is most preferably 140 ~ 200 ℃, the interlayer temperature is the temperature of the welded portion just warmed by the previous welding layer welding heat immediately before generating an arc in the multi-layer welding, it is completed through several welding layers The weld is affected by the residual heat of the weld layer immediately before welding. If the interlayer temperature is 200 ° C. or higher, excessive heat input causes deterioration of strength and impact resistance, so the above range should be observed.

The present invention can be used for grinding rolls and rotating plates of the mill. The fine powder according to the prior art has a large amount of abrasion at the part with relatively high friction, so that a long period of use may cause a concave shape due to single abrasion, thereby preventing smooth grinding.

In the grinding roll of the present invention, the hardened layers 3a, 3b, 3c, and 3d are thickly raised and welded to a portion with high friction, and the hardened layer 3a to a relatively low friction portion as shown in FIG. , 3b, 3c, and 3d) are thinly grown and welded. In the case of Figure 4 (a) shows the cross-sectional shape of the conical grinding roll to grow and weld the gradually thinner thickness of the hardened layer (3a, 3b, 3c, 3d) from the large diameter roll portion to the smaller roll portion 5 (b) shows a cross-sectional shape of a cylindrical pulverizing roll having a central convex, wherein the central portion of the hardened layer is thickly welded and welded to become thinner toward both ends. Therefore, as the hardened layer is welded only to the areas where the wear is severe, the content of the hardened layer can be lowered to reduce the production cost, and the entire grinding roll is uniformly worn, thereby having a smooth grinding performance even when used for a long time.

In the rotary plate of the present invention, the hardened layers 3a, 3b, 3c, and 3d are formed to be thickly welded on the parts with high friction, such as the shape of FIG. 5, and the hardened layer 3a on the parts with less friction. , 3b, 3c, and 3d) are welded so as to be thin. In the case of Figure 5 (a) shows a disk-shaped rotating plate is a heavy friction wear hardened layer thicker in the central portion of the wear, and the hardened layer is gradually welded to become thinner toward the outer friction less friction. In the case of (b) of FIG. 5, the hardened layer is thickly welded in the concave central portion of the rotating plate having a concave shape, and the hardened layer is gradually welded to the outer side where the friction is less severe. Therefore, by hard welding the hardened layer only in the areas where the wear is severe, it is possible to reduce the production cost by lowering the content of the hardened layer, and because the entire rotating plate is uniformly worn, it has a smooth grinding performance even when used for a long time.

Hereinafter, the present invention will be described in detail through examples.

In the practice of the present invention, the components are primarily in weight percent of C: 4.2 to 5.0% and Si: 0.5 to 1.5 on a base material (1a, 1b, 1c, 1d) made of cast steel having a thickness of 35 mm, a width of 200 mm, and a length of 200 mm. %, Mn: 0.5 ~ 1.4%, Cr: 23.0 ~ 25.0%, Mo: 0.5 ~ 1.0%, the conventional fusing welding material composed of the remaining Fe and other unavoidable impurities. In weight%, C: 4.5-6.0%, Si: 0.6-2.5%, Mn: 0.1-2.0%, Cr: 22.0-26.0%, Mo: 4.5-6.0%, Nb: 2.5-4.5, V: 0.5-2.0 Cemented carbide welding material composed of%, W: 4.0 ~ 10.0%, remaining Fe and other unavoidable impurities, and raised and welded the hardened layer (3a, 3b, 3c, 3d) to 20mm in thickness. It was.

TABLE 1

TABLE 2

Table 2 shows the hardness and wear when the multilayer growth welding is performed so that a cured layer having a new component composition is formed in the conventional example and the conventional growth welding layer. Inventive examples in the component composition range of the present invention is excellent in hardness compared to the prior art it can be seen that the wear amount is small, in the case of the comparative example outside the component composition content of the present invention it can be seen that the hardness and wear amount is reduced.

Table 3

Table 3 shows the check crack size (X, Y), the welding state and the wear amount according to the preheating temperature and the interlaminar temperature in the multilayer growth welding method of the present invention. In the case of the present invention, the check crack size (X, Y) is in the range of 5 ~ 20㎜ it can be seen that the welding state is good and the wear amount is small, but the check crack size when the preheat temperature and the interlayer temperature is outside the temperature range of the present invention (X, Y) was 5 mm or less, or 20 mm or more, and the phenomenon that the weld layer peeled off occurred.

1 is a schematic cross-sectional view of a conventional grinding mill roll.

2 is a schematic cross-sectional view of a grinding wheel of the prior art.

Figure 3 is a schematic diagram showing the shape of the multi-layer growth welding layer of the present invention.

Figure 4 is a schematic cross-sectional view of the grinding mill grinding roll of the present invention.

5 is a schematic cross-sectional view of the grinding plate of the present invention.

* Description of the symbols for the main parts of the drawings *

1a, 1b, 1c, 1d: base material 2a, 2b, 2c, 2d: base layer

3a, 3b, 3c, 3d: hardened layer

X: Check Crack Width Size Y: Check Crack Width Size

Z: hardened layer thickness

Claims (10)

In the multilayer growth welding layer formed on the surface layer of the base material of spheroidal graphite iron or cast steel, The multilayer growth welding layer is composed of a base layer having a hardness greater than the hardness of the base material and a cured layer having a hardness greater than the hardness of the base layer, The base layer by weight, C: 4.2 ~ 5.0%, Si: 0.5 ~ 1.5%, Mn: 0.5 ~ 1.4%, Cr: 23.0 ~ 25.0%, Mo: 0.5 ~ 1.0%, the remaining Fe and other unavoidable impurities Is composed, The hardened layer is in weight%, C: 4.5-6.0%, Si: 0.6-2.5%, Mn: 0.1-2.0%, Cr: 22.0-26.0%, Mo: 4.5-6.0%, Nb: 2.5-4.5, V : 0.5 ~ 2.0%, W: 4.0 ~ 10.0%, remaining Fe and other unavoidable impurities, The check cracks are continuously formed in a multi-layered structure in which bricks are stacked and woven together. The check cracks have a horizontal and vertical size of 5 to 20 mm and a weld layer thickness of 5 to 40 mm for the entire hardened layer. It is a multilayer growth welding layer excellent in wear resistance. delete delete delete delete delete A base layer having a hardness greater than the hardness of the base material and a hardened layer having a hardness greater than the hardness of the base layer are sequentially formed on the base material of spherical graphite cast iron or cast steel, and includes a multilayer growth welding layer. The base layer by weight, C: 4.2 ~ 5.0%, Si: 0.5 ~ 1.5%, Mn: 0.5 ~ 1.4%, Cr: 23.0 ~ 25.0%, Mo: 0.5 ~ 1.0%, the remaining Fe and other unavoidable impurities Is composed, The hardened layer is in weight%, C: 4.5-6.0%, Si: 0.6-2.5%, Mn: 0.1-2.0%, Cr: 22.0-26.0%, Mo: 4.5-6.0%, Nb: 2.5-4.5, V : 0.5 ~ 2.0%, W: 4.0 ~ 10.0%, remaining Fe and other unavoidable impurities, The multi-layered welding welding layer is formed in a multi-layered check crack is formed in a multi-layered structure of the bricks are interwoven with each other, the check crack is a horizontal and vertical size of 5 ~ 20㎜ each hardened layer total weld layer thickness Is 5-40 mm, Grinding layer with excellent wear resistance, characterized in that the hardened layer in the area of high wear due to the high friction, the thickness is formed thick, and the hardened layer in the area of low wear due to the friction is raised and welded to form a thin thickness. A base layer having a hardness greater than the hardness of the base material and a hardened layer having a hardness greater than the hardness of the base layer are sequentially formed on the base material of spherical graphite cast iron or cast steel, and includes a multilayer growth welding layer. The base layer by weight, C: 4.2 ~ 5.0%, Si: 0.5 ~ 1.5%, Mn: 0.5 ~ 1.4%, Cr: 23.0 ~ 25.0%, Mo: 0.5 ~ 1.0%, the remaining Fe and other unavoidable impurities Is composed, The hardened layer is in weight%, C: 4.5-6.0%, Si: 0.6-2.5%, Mn: 0.1-2.0%, Cr: 22.0-26.0%, Mo: 4.5-6.0%, Nb: 2.5-4.5, V : 0.5 ~ 2.0%, W: 4.0 ~ 10.0%, remaining Fe and other unavoidable impurities, The multi-layered welding welding layer is formed in a multi-layered check crack is formed in a multi-layered structure of the bricks are interwoven with each other, the check crack is a horizontal and vertical size of 5 ~ 20㎜ each hardened layer total weld layer thickness Is 5-40 mm, A hardened layer having a high frictional wear at the site of high wear due to high friction, and a hardened layer at a low wear due to low friction, which has been grown and welded to form a thin thickness. delete delete

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