JPH0751585A - Shattering face member used in grinder - Google Patents

Abstract

PURPOSE:To prepare simply a shattering face member on the surface layer part of which a block with a low wear resistance and a block with a high wear resistance are alternatively arranged. CONSTITUTION:The surface layer part is formed out of a matrix metal 1 with a low wear resistance. Channels 2 are provided on the surface of the matrix metal 1. A wear-resistant metal 3 is filled as one layer in each channel 2 by casting. Shrinkage caused by solidification of the wear-resistant metal 3 is absorbed by deformation of walls 4 and 4 on the both sides of the channel 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crushing surface member used in a crusher of the type in which material is continuously caught between crushing surfaces to crush the material. Examples of this type of crusher include a roll crusher, a cone crusher, a ring roll mill, a rigid roller mill, and an edge runner.
The crushing surface member refers to a roll, a roller, a tire, a table liner or the like that constitutes a crushing surface in such a crusher.

[0002]

2. Description of the Related Art Conventionally, for crushing various materials such as iron ore, coal, coke, graphite, converter, blast furnace slag, limestone, clinker and rock, rolls, rollers, tires,
Various crushers that combine crushing surface members such as a table liner are used.

In order to improve the crushing efficiency in such a crusher, the applicant of the present invention crushes by arranging at least two kinds of blocks having different wear resistance in the surface layer portion alternately in the direction in which the material is bitten. The surface member was first developed (Patent No. 1618574). A typical example of this crushing surface member is shown in FIG.
Shown in 1.

The crushing surface member shown here is a crushing mill roller. The mill rollers are placed opposite to each other with a predetermined space therebetween, and the material is continuously bitten between them to crush the material. The direction in which the material is bitten is the circumferential direction of the mill roller.

The surface layer of the mill roller is a base metal 1 such as mild steel.
Consists of. A large number of grooves 2, 2 ... That extend in the direction of the roller axis are provided on the surface of the base metal 1 at predetermined intervals in the circumferential direction. Each groove 2 is filled with a wear resistant metal 3 such as high carbon high chromium steel.

As a result, in the surface layer portion of the mill roller,
The blocks having high wear resistance and the blocks having low wear resistance are alternately arranged. That is, the groove 2 on the surface of the base material
The wear-resistant metal 3 filled inside becomes a block having high wear resistance, and the walls 4 and 4 on both sides forming the groove thereof become blocks having low wear resistance.

[0007] In such a mill roller, even if the surface is flat before use, the surface of the block having low wear resistance is selectively worn by use, and a dent is formed there. In such a state, the material is better caught and the pulverization efficiency is rapidly improved. This state is continued until the wear-resistant block reaches the limit of use.

[0008]

By the way, in such a mill roller, it is common to fill wear-resistant metal by multilayer build-up by downward automatic arc welding. Adopted the method.

However, in the overlaying by downward automatic arc welding, the beat width is 10 to 30 mm and the bead height is only 3 to 5 mm in one layer. On the other hand, the height of the block having high wear resistance in the mill roller may exceed 60 mm in some cases. Therefore, it takes a long time to fill the wear resistant metal. There is also a problem that many cracks occur in the filling metal.

An object of the present invention is to provide a crushing surface member which is excellent in productivity and can be filled with the metal in a short time even when the height of the block having high wear resistance is high.

[0011]

The crushing surface member of the present invention comprises:
A crushing surface member of a crusher in which a material is continuously bitten between opposing crushing surfaces to crush it, and at least the surface layer is composed of a base metal with low wear resistance, and a large number of base metal surfaces. The recesses are regularly formed, and each recess is filled with a metal having high wear resistance, which is continuously formed in the depth direction by casting.

[0012]

As a welding overlay method for providing a thick wall, there is a vertical single-layer overlay method using high heat input welding such as electroslag welding, electrogas welding, and electronongas welding. This method is a single-layer vertical welding method developed at the Patong Research Center in the Kiev City of the former Soviet Union around 1951. The original usage is, for example, when butt welding a thick plate material of 40 mm or more, Butt interval is about 20 ~
A 30 mm I-shaped groove is formed, and the groove is set up and the groove is surrounded by water-cooled copper metal from both sides. The electrode wire is melt-filled into the groove from bottom to top using the above-mentioned large heat input welding method. Then, the plate material is welded.

In this vertical single-layer weld overlay method, 3 to 6 electrode wires are inserted in the groove and overlaying can be performed with multiple electrodes. Therefore, even a steel sheet having a thickness of more than 300 mm can be highly efficient. Can be welded. For example, a steel plate with a wall thickness of 300 mm
If welded over a length of 1000 mm, the arc time would be about 2 hours. If this is done by downward welding, even if the submerged arc welding which is said to have the highest efficiency is used, the arc time of about 7 to 10 hours is required. Both welding methods use 3 electrodes, welding current is 600A,
The groove spacing is 50 mm.

That is, there is a difference in efficiency of about 3.5 to 5 times between the vertical single-layer weld overlay and the downward weld overlay. Although this comparison is limited to the comparison of the arc time, an even larger difference occurs when the setup time required for welding and the labor time involved in the welding are taken into consideration. Thus, the vertical single-layer weld overlay method is very efficient.

However, when the wear-resistant metal is overlaid on the entire surface of the crushing surface member by using this vertical single-layer welding overlay method, cracks occur due to the shrinkage stress of the overlay metal and the overlay height is increased. Is limited to about 30 mm at the maximum, and peeling off occurs during use if the padding is performed to a height higher than this.

However, in the crushing surface member targeted by the present invention, the wear-resistant metal is built up in the concave portion of the surface of the base material, and the hard wear-resistant metal is surrounded by the soft base material metal having high toughness. , Because the build-up can be completed for each recess, 30
Even if it is overlaid with a thickness of mm or more, it is unlikely to peel off during use.

That is, in the crushing surface member targeted by the present invention, when the wear-resistant metal filled in the recess is solidified, the wall around the recess is deformed due to the shrinkage of the wear-resistant metal. Therefore, the residual stress of the wear resistant metal is reduced. Moreover, since the wear-resistant metal filled in the recesses is small in amount, the residual stress is essentially small. Furthermore, the cooling is slow due to the single layer packing. As a result, even when the wear-resistant metal is filled in a single layer in the recess having a depth of more than 60 mm, it becomes easy to prevent the wear-resistant metal from cracking. Therefore, it is possible to perform highly efficient filling by the vertical single-layer weld overlay.

When the concave portion on the surface of the base material is a groove, the groove is surrounded from the side by a metal, and an appropriate number of electrode wires are inserted into the groove from above and the molten meat is sequentially melted from bottom to top. It's good to do the prime.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an example of the crushing surface member of the present invention, FIG. 2 is a developed view of the surface of the crushing surface member, FIG. 3 is a sectional view of the surface layer portion of the crushing surface member, and FIG. 4 is welding. FIG. 5 is a perspective view showing the method, and FIG. 5 is a view taken along the line AA of FIG.

The crushing surface member shown here is a mill roller. The surface layer of this mill roller is made of a base metal 1 such as mild steel. On the surface of the base metal 1, a large number of grooves 2, 2 ... Which are parallel to the roller axis are provided as concave portions at predetermined intervals in the circumferential direction. Each groove 2 is also formed by welding a rib material of the same material as the base material to the surface of the base metal roller.

Inside each groove 2, wear resistant metal 3 such as high carbon high chromium steel is erected in a vertical direction using large heat input welding such as electro slag welding, electro gas welding and electro non gas welding. It is cast by layer weld overlay.

The wear-resistant metal 3 cast in the groove 2 has a bottom surface of the groove 2 and a pair of walls 4 forming the groove 2.
It is welded to the opposite side surface of No. 4. The walls 4 and 4 are a part of the base metal 1 and have lower wear resistance than the wear resistant metal 3. When the rib material is used, the rib material becomes the wall 4.

In casting, for example, the groove 2
Is laid down and both ends thereof are closed with a metal, and the wear resistant metal 3 is filled in the inside by the above-mentioned single-layer weld overlay. This operation is sequentially performed on all the grooves 2, 2 ....

For more efficient casting,
As shown in FIGS. 4 and 5, the groove 2 is set up and the groove 2 is laterally surrounded by a metal plate 5, and an appropriate number of electrode wires 6 are inserted into the groove 2 from above, and the grooves are sequentially melted from bottom to top. It is good to build up. That is, the single-layer overlay is performed in the same manner as the butt welding of the thick steel plates described above.

The metal 5 may be water-cooled or air-cooled, and it may be the one that surrounds the entire groove 2 from the beginning, or it may be moved upward as the build-up progresses.

Although the depth D of the groove 2 may reach 200 mm in some cases, high efficiency welding overlay can be performed by inserting a plurality of electrode wires 6 in the depth direction. The width W of the groove 2 may exceed 100 mm in some cases, but even in such a case, it is possible to perform high-efficiency welding overlay by adding electrode wires in the width direction.

If the number of wires in one groove 2 is increased, the efficiency can be improved as much as possible. Further, since a large number of grooves 2 are provided in the circumferential direction of the roller and all are in a standing state, it is possible to build up a plurality of grooves 2 simultaneously. If all the grooves 2 are built up at the same time, casting is completed in a short time.

At the starting point of welding, the heat input for welding is insufficient, and fusion defects are likely to occur. In FIG. 5, for this purpose, the groove 2 is shallow on one end side. Since the end of the groove 2, that is, the end of the roller is usually less worn, even if the amount of wear-resistant metal is slightly insufficient, no problem occurs.

As shown in FIG. 6, a vertical single-layer weld overlay having such grooves is provided with a roller having a cylindrical outer peripheral surface (A in the same figure) and a roller having a truncated cone-shaped outer surface (same as the same). B), a tire having a cylindrical or frusto-conical inner surface (FIG. C), a table having a planar surface, and the like, which are preferably used for long continuous grooves in the longitudinal direction.

Regarding the welding start position, basically, the groove 2 is used.
Either of the both ends may be adopted, but in the case of a roller having a truncated cone-shaped outer surface, since the progress of wear is remarkable on the large diameter side, it is preferable to select the welding start point on the small diameter side.

It is now assumed that the groove 2 of FIG. 2A is cast and then the groove 2 of B is cast. B
The wear-resistant metal 3 cast in the groove 2 of B shrinks in the process of solidification. At this time, a and b sandwiching the groove 2 of B are sandwiched.
Of the walls 4 and 4 of A, the wall 4 of A is restrained by the wear-resistant metal 3 cast in the groove 2 of A, but b
Since the wear resistant metal 3 is not cast in the groove 2 of C, the wall 4 is unconstrained. Therefore, B
The solidification shrinkage of the wear resistant metal 3 cast in the groove 2 is absorbed mainly by the deformation of the wall 4 of b. Therefore, the residual stress of the wear resistant metal 3 cast in the groove 2 of B is reduced.

Further, although the total amount of the wear resistant metal 3 cast in the groove 2 is small, the casting is performed all at once, so that the cooling is gradually cooled. As a result, even when the groove 2 has a depth of more than 60 mm, the groove 2
The wear-resistant metal 3 cast therein is prevented from cracking, or the number of cracks is significantly smaller than the number of cracks generated by the downward facing overlay.

FIG. 7 is a development view showing another structure of the crushing surface member of the present invention.

In this embodiment, a partition wall 5 for partitioning the groove 2 in the longitudinal direction is provided. By providing the partition wall 5, the volume of the groove is reduced, so that the amount of casting metal is reduced. As a result, the shrinkage stress is reduced, and the effect of preventing cracking is obtained. In the present embodiment, the partition wall 5 is also displaced by a half pitch between the adjacent grooves 2 and 2. This has the effect of preventing extreme wear of the partition wall 5. Further, in FIG. 7B, the partition wall 5 is inclined with respect to the circumferential direction of the roller, but this is aimed at the effect of scraping the pulverized raw material.

FIG. 8 is a sectional view showing still another structure of the crushing surface member of the present invention.

In this embodiment, the opposing side surfaces of the walls 4 and 4 which are opposed to each other with the groove 2 interposed therebetween are curved outward. By doing so, the wear-resistant metal 3 cast in the groove 2 becomes an egg shape having a long elliptical cross section, and the load applied in the major axis direction of the wear-resistant metal 3 and the walls 4, 4 is a fusion surface. In the tangential direction (X direction) and the direction perpendicular to the tangent (Y
Direction). Therefore, as compared with the case where the side surfaces of the walls 4 and 4 are vertical, the load in the tangential direction applied to the fusion surface is reduced, and peeling at the fusion surface is suppressed. Further, the component force in the direction perpendicular to the tangent line cancels out the component force in the direction perpendicular to the adjacent tangent line, and the breakage of the walls 4 and 4 is prevented. Therefore, this roller is very strong against an impact applied perpendicularly to the surface.

The depth of the groove 2 in the fracture surface member of the present invention,
That is, the height of the wear-resistant metal 3 is 10 mm or more, 20
0 mm or less is desirable. If it is less than 10 mm, sufficient abrasion resistance cannot be obtained and the construction becomes difficult. If it exceeds 200 mm, the filling amount of the wear-resistant metal in one groove groove becomes too large, the shrinkage stress of the wear-resistant metal increases, and it becomes difficult to prevent cracks, and many cracks occur. become.

In the vertical single-layer overlay method, the welding heat input is enormous as compared with the downward weld overlay method, and therefore the penetration depth is likely to be deep. The thickness w _{1 of the} wall 4 is preferably 0.1 w ≦ w ₁ ≦ 1 w in the case of downward welding overlay. However, in the case of vertical single-layer overlay, 0.25 is taken into consideration in consideration of depth and penetration.
It is desirable that w ≦ w ₁ ≦ 1w. In all cases, 5m
m or more is desirable. w is the width of the groove 2.

When the thickness w _{1 of the} wall 4 is small, the crushed raw material is difficult to be caught, and when w ₁ <5 mm, the wall 4 has a heat input for welding.
Melts and penetrates easily. When it exceeds 1 w, the thickness of the wall 4 becomes too thick and the wear is accelerated and deeply worn, so that the end face edge of the wear resistant metal is likely to be chipped.

The thickness w ₂ of the partition wall 5 is 5 mm or more and 25 mm
The following is desirable. If the thickness is less than 5 mm, the wall is likely to melt and penetrate due to welding heat input. If it exceeds 25 mm, the thickness becomes too thick and is easily worn. That is, the same result as when 1 or more of w ₁ is obtained.

The pitch P of the partition wall 5 is 25 mm or more and 200
mm or less is desirable. If it is less than 25 mm, the casting volume of the groove becomes too small, resulting in poor efficiency. If it exceeds 200 mm, the volume of the groove becomes too large, and unless two or more electrodes are used, casting becomes difficult and the overlaying operation becomes complicated. Further, the amount of wear-resistant metal increases, the contraction stress increases, and cracks easily occur.

The inclination angle θ of the partition wall 5 is preferably 45 ° or less. If it exceeds 45 °, the shape of the groove becomes a parallelogram having an acute angle, and it becomes difficult to build up the acute corner portion.

As the base metal 1, specifically, mild steel (S
S400), rolled steel for welded structure (SM), ordinary cast steel (SC), forged steel, carbon steel, stainless steel, 14% manganese steel, and other easily welded steel materials are desirable.

The wear resistant metal 3 is C2.5 to 7.0.
%, Cr 15 to 35%, a high carbon high chromium cast iron-based alloy as a main component, and other carbide forming elements Nb, W, Mo, V, T
An alloy in which i, B, etc. are added individually or in combination is desirable.
For example, C4% -Cr22% -Nb8% is often used in roll development.

Then, the materials of the base metal 2 and the wear resistant metal 3 are combined so as to secure the hardness difference such that the depth of the stable recess formed in the wall 2 is 0.5 to 15 mm.

In the above description, the recess is a groove, but the recess may be square, polygonal or circular as shown in FIG. That is, the crushing surface member in which the wear-resistant metal 2 is not continuous in one direction and a large number of wear-resistant metals 2 having a point-symmetrical shape are regularly arranged is also within the scope of the present invention.

In the case of such a crushing surface member, depending on the rotating direction of the roller, the tire and the table, the soft wall 4 formed between the adjacent wear resistant metals 3 and 3 may be easily worn by the crushed raw material. . The direction is indicated by an arrow,
This is the direction of rotation of the roller, the direction of rotation of the table, that is, the direction in which the material is bitten, and in this direction the wall 4
When the directions of 3 and 4 coincide, the wear of the wall 4 becomes significant.

In order to suppress this, as shown in FIG. 10, it is preferable to incline the wall 4 with respect to the direction in which the material is bitten. The inclination angle is preferably 30 to 60 °, particularly preferably about 45 °. This inclination also contributes to improving the biting property of the material.

Finally, the results of carrying out the present invention will be described.

The present invention was applied to a roller of a coal crushing roller mill for supplying pulverized coal to a rotary kiln of a cement factory.

In this mill, three rollers are installed inside the ring, and each roller rotates and rises by centrifugal force to pulverize the raw material with the ring. As a raw material, coal having a diameter of about 50 mm is charged, and the particle size after crushing is 200 mesh under 85%.

The base metal roller has a frustoconical outer surface, the outer diameter on the large diameter side is about 970 mm, and the outer diameter on the small diameter side is about 7 mm.
The length is 85 mm and the length in the central axis direction is 420 mm. Forty-five pieces of mild steel rib material as walls are welded to this outer peripheral surface at equal intervals in the circumferential direction, and the width is 59 mm on the large diameter side and 48 mm on the small diameter side.
45 grooves having a width and a depth of 40 mm were formed. Welding is performed with the vertical axis of the center axis of the roller and the vertical single-layer weld overlay using non-gas arc welding on each of the vertical grooves.
C5.5% -Cr22% -Nb8% -Mo7% -W2%-
V1.5% wear resistant metal was cast in sequence.

The welding conditions are as follows. Electrode 1 electrode Welding current 450A (DC reverse polarity) Welding voltage 34 to 36V Wire melting amount 8kg / hour Wire total usage amount 270kg

Since 50 kg of wire can be used per day (8 hours), the build-up was completed in 5 to 6 days.

When this is overlaid by conventional downward welding (submerged arc welding), the following conditions are obtained. Welding current 350A (DC reverse polarity) Welding voltage 28-32V Wire melting amount 5kg / hour

The welding current is lower than that in vertical welding.
This is because, if the current is increased too much in the downward welding, the amount of the wire melted is too large, and in the build-up inside the groove, the molten metal precedes the arc point and there is a risk of defective fusion.

The maximum thickness of each layer is about 5 mm. It is thought that about 10 mm is possible if it is not possible, but it is actually impossible because there is a risk of peeling when an impact is applied during use. Therefore, it becomes multi-layer welding, and it is necessary to consider that the arc time rate is 50%.

Therefore, in the conventional method, about 20 k per day
Only g of wire could be used and 13-14 days were required for full buildup. That is, according to the present invention, the efficiency is about 2.6.
Doubled. Further, if the overlaying is performed with a four-electrode wire, an efficiency improvement of about 10 times can be achieved.

Conventionally, crusher rollers and tires are 14%
Manufactured from manganese steel, 21% manganese steel, high chromium cast iron. Since these materials are large crushers, in order to avoid accidents where the rollers, the table liner, etc. are broken during use, wear resistance is sacrificed and the materials have break resistance. Therefore, it has a short service life and must be replaced frequently.

For example, the life of the grinding roller of the raw material mill in the cement factory is about 4000 hours on average. When this is corrected to the moon, it is about 5.5 months. The cement plant wants to extend this to about one year.

In the build-up roller, mild steel or ordinary cast steel, which is resistant to breakage, can be used as the base material, and the hard-facing build-up metal is welded on the base material, so that there is an advantage that a metal having extremely excellent wear resistance can be used. That is, this can be achieved by combining a base metal roller having excellent toughness and a weld metal having excellent wear resistance.

As the wear-resistant weld metal, for example, C5.5%,
Those having chemical components of Cr22%, Nb8%, Mo7%, W2% and V1.5% can be used. It has very good abrasion resistance and its hardness is HRC63-65. When this is compared with high chromium cast iron, its wear resistance is about 4 to 5 times.

However, in recent years, in order to reduce the production cost, a crusher used in a cement factory or an iron mill becomes very large, and it is necessary to give a large amount of welding to build up the roller. The conventional downward facing welding method is remarkably inefficient, and the overlaying cost becomes high, which is not profitable. Also, the welding quality is not good.

The present invention overcomes this situation, enables the welding of hardfacing metal to a large grinding roller, which has been considered impossible in the past, and greatly extends its service life.
It can make a huge contribution to the industry.

The present invention is not limited to rollers, but tires,
It can be applied to a table or the like as described above.

Casting of the wear-resistant metal into the recess can be carried out not only by vertical single-layer weld overlaying, but also by pouring a molten metal in advance.

[0068]

EFFECTS OF THE INVENTION Since the crushing surface member of the present invention is a single layer filled with wear-resistant metal by casting in the concave portion provided on the surface of the base metal, the filling does not take time, Productivity is significantly improved. In addition, even though the wear-resistant metal is filled in a single layer in the recesses, the solidification shrinkage is absorbed by the deformation of the walls that sandwich the groove, so it is possible to prevent the wear-resistant metal from cracking. Or it can be greatly reduced. Further, even when the wear-resistant metal is thick, it is possible to suppress peeling-off during use.

Therefore, blocks having low wear resistance and blocks having high wear resistance are alternately arranged, and the crushing surface member having thick and durable blocks having high wear resistance includes large ones. Manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a crushing surface member of the present invention.

2 is a development view of the surface of the crushing surface member of FIG. 1. FIG.

FIG. 3 is a sectional view of a surface layer portion of the crushing surface member of FIG.

FIG. 4 is a perspective view showing a welding method.

5 is a view taken along the line AA of FIG.

FIG. 6 is a perspective view showing a representative object of the present invention.

FIG. 7 is a development view showing another example of the crushing surface member of the present invention.

FIG. 8 is a sectional view showing still another example of the crushing surface member of the present invention.

FIG. 9 is a development view showing another example of a recess.

FIG. 10 is a development view showing another arrangement example of concave portions.

FIG. 11 is a perspective view showing a configuration of a conventional crushing surface member.

[Explanation of symbols]

 1 Base metal 2 Groove (concave) 3 Abrasion resistant metal 4 Wall 5 Partition wall

Claims (3)

[Claims] 1. A crushing surface member of a crusher in which a material is continuously bitten between opposing crushing surfaces for crushing, and at least a surface layer is made of a base metal having low wear resistance, and a base material thereof is used. Used for a crusher characterized in that a large number of recesses are regularly formed on the surface of the material metal, and each recess is filled with a highly wear-resistant metal continuously formed in the depth direction by casting. Crushed surface member. 2. The crushing surface member used in the crusher according to claim 1, wherein the recesses are grooves arranged in parallel at intervals in a direction in which the material is bitten. 3. The crushing surface member used in the crusher according to claim 1, wherein the casting is a vertical single-layer weld overlay.