JPH0245522B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a composite casting roller having a long and narrow body and a relatively short neck compared to the length of the body. In general, rollers attached to rolling mills for steel materials, such as hot run table rollers, conveyance rollers, overrun table rollers, day table rollers, bottom pinch rolls of coilers, and wrapper rollers, are as shown in Figure 1.
The trunk length l is long with respect to the trunk diameter D ₁ of the trunk 1, and the diameter D _o of the neck parts 2 and 3 is small.
The neck lengths l ₁ and l ₂ at both ends are shorter than the trunk length l.
That is, in numerical terms, D ₁ /l = 0.12 to 0.25 D _o /D ₁ = 0.3 to 0.55 l ₁ /l or l _{2 /} l = 0.05 to 0.55, and regarding the waste diameter D ₂ of the roller is in the range of D ₂ /D ₁ =0.70 to 0.95. Conventionally, when manufacturing a roller having such a shape, as shown in FIG. 2, the body sleeve 4 is manufactured separately, and the shaft 5 is attached to the body sleeve 4 by means of shrink fitting, gluing, etc. with the fixing portions 6, 6. An assembly method has been adopted in which it is fixed to the Here, the torso sleeve 4 is
In addition to being a single-layer sleeve, there is also a composite sleeve consisting of a first outer layer whose surface layer is made of a wear-resistant material and a second outer layer whose lower part is made of a tough material, while the shaft 5 is made of carbon. Tough materials such as steel and alloy steel are used. Further, as shown in FIG. 3, shaft members 8 and 9 which are not integrated at both ends of the body sleeve 7 similar to those described above may be assembled by a method such as shrink fitting using fixed portions 10 and 11. However, in the case of the roller shown in FIG. 2, since the body sleeve 4 is elongated, it is difficult to machine a long and small diameter shaft hole, and the shaft 5 must also be machined over its entire length, which is not economical. Further, in the case of the roller shown in FIG. 3, it is necessary to perform difficult shaft hole machining in the body sleeve 4, and since the shaft is divided, the strength remains unreliable. That is, Fig. 2,
The roller shown in FIG. 3 has a very elongated shape as shown in the above-mentioned numerical values, so it is difficult to manufacture and the processing is uneconomical. Suppose, like a normal roll, the body diameter D ₁ and the body length l
If the dimensions are relatively large, the value of D ₁ /l is larger than the above-mentioned value, and it is thick and short, the above-mentioned problems in processing will not occur. The present invention was made in view of the above points, and aims to provide a manufacturing method for a composite casting roller that is easy to manufacture and economical, and the gist thereof is to provide a method for manufacturing a composite casting roller that is easy to manufacture and is economical. The outer shell layer of the cylindrical composite material, which has a diameter slightly larger than the overall length and is longer, is centrifugally cast, and then the core of the cylindrical composite material, which will become the body core and neck portion of the desired roller, is cast. After being metallurgically welded and integrated with the outer shell layer, the cylindrical composite material is cut out, with body diameter: D ₁ , waste diameter: D ₂ , neck diameter: Dn, body length: l, and the shapes of both ends of the body. Chief Netsuku:
l ₁ · l ₂ , body core diameter: D ₃ , D ₂ /D ₁ = 0.7 to 0.95 D ₁ /l = 0.12 to 0.25 Dn/D ₁ = 0.3 to 0.55 l ₁ /l or l ₂ /l = 0.05~0.20 _D3 / _D1 =0.55~0.70 Dn< _D3 < _D2 . Next, this invention will be explained in detail. FIG. 4 shows an example of a composite casting roller manufactured by the method of the present invention, in which the shell outer layer 13 is made of a material with excellent wear resistance, roughness resistance, and heat cracking resistance, and the outer shell layer 13 has excellent toughness. The core part 14 is metallurgically welded and integrated with the body core part 14 made of a particularly excellent tough material, and its dimensions and shape satisfy the relationships stated in the gist of the present invention. is shown below. D ₂ /D ₁ = 0.7 to 0.95 If the waste diameter D ₂ is less than 0.7 with respect to the body diameter D ₁ , the wall thickness between the roller surface and the body core surface during disposal will be too small, and the core material will be exposed. while 0.95
In the above case, the number of effective users decreases and it is not economical. Also, it is not a common roller shape. D ₁ /l=0.12 to 0.25 D ₁ /l indicates the ratio of the barrel diameter D ₁ to the barrel length l, and this value indicates that the roller has an elongated shape.
In the case of short rollers exceeding 0.25 mm, it is relatively easy to process the inner diameter. On the other hand, elongated rollers with a diameter of less than 0.12 are not common, and also cause problems with poor welding and uniformity of the outer shell layer thickness during centrifugal casting described below. Dn/D ₁ = 0.3 to 0.55 Dn/D ₁ indicates the ratio of the neck diameter Dn to the body diameter D _1. If it is less than 0.3, it will be uneconomical to carve out the neck from the cylindrical composite material described below, and 0.55 If it exceeds , D ₂ will also increase and the effective usage layer will decrease. l ₁ /l or l ₂ /l = 0.05 to 0.20 l ₁ or l ₂ indicates the neck length, and if it exceeds 0.20,
It is uneconomical to cut out the neck part from a cylindrical composite material. Anything less than 0.05 is not common for roller shapes. Dn<D ₃ <D ₂ D ₃ If the diameter of the axial core, that is, the diameter of the boundary between the outer shell layer and the axial core, is larger than the neck diameter Dn and smaller than the disposal diameter D ₂ , the outer shell layer will be removed during disposal. The thickness of the core material is insufficient, and the core material is exposed on the surface of the body. If _D3 is smaller than Dn, a hard outer shell material remains at the neck, and the strength of the neck cannot be ensured. In addition, Dn＜
If each value of D ₃ < D ₂ is divided by D ₁ , the above Dn/D ₁ and
Due to the limitation of D ₂ /D ₁ , D ₃ /D ₁ =0.55 to 0.70. When manufacturing a composite casting roller according to the present invention, first, a diameter and a length larger than the body diameter D ₁ and overall length L of the composite casting roller in the final shape shown in FIG. A cylindrical composite material 17 shown in FIG. 5 has a long body diameter _D1 ' and a full length L', and has an outer shell layer 18 and a core part 19 made of different materials that are metallurgically welded and integrated. is manufactured first. To describe the manufacture of the cylindrical composite material 17 in more detail, first, the outer shell layer 18 of the cylindrical composite material 17 is made of high alloy grain material, high alloy chilled material, high chromium cast iron,
After centrifugal casting of materials with excellent wear resistance, roughness resistance, and heat cracking resistance such as high-hardness adamite material and high-alloy ductile cast iron, particularly strong materials such as cast steel material, adamite material, graphite steel material, and ductile cast iron are used. The core portion 19 is cast with a material and is metallurgically welded and integrated with the outer shell layer 18. At the time of this casting, if the outer shell layer 18 is horizontal centrifugal casting, after the outer shell layer 18 is completely solidified, the mold of the centrifugal casting machine is stood vertically and the core member molten metal is cast. In the case of die centrifugal force casting, after the outer shell layer 18 is formed, the core member molten metal is subsequently cast into the casting machine mold. In this case, the core portion 19 of the cylindrical composite material 17 is
Core part 1 of the composite casting roller intended as it is
4, so the dimensional relationship stated in the gist of the present invention,
That is, the relationship Dn<D ₃ <D ₂ must be satisfied. Next, the cylindrical composite material 17 is machined,
Cut to the desired size and shape of the composite casting roller. In this machining, the workpiece is rod-shaped, and machining of long and small diameter shaft holes, which is difficult to machine, is not involved, and in addition, the lengths _l1 and _l2 of the neck portions 15 and 16 are longer than the body length l.
Since l ₁ /l or l ₂ /l is short (0.05 to 0.2), processing is very easy and there are few removed parts, so it is economical. The diameter of the cut out neck portions 15 and 16 is
Since the dimension Dn is specified as Dn<D ₃ , it becomes a strong material similar to the trunk core 14, eliminating concerns about breakage and insufficient strength. By the way, as shown in FIG. 6, there are tapered sand mold sleeves 21 at both ends of the centrifugal casting machine mold 20.
The roller of the present invention can be manufactured even by using a conventional composite roll mold in which the roller 21 is fixedly fitted, but in this case, the roller body diameter D ₁ and the neck diameter Dn are small. , it is difficult to form a mold and pour the metal into the shell shell layer 13, and furthermore, with this method, the cooling of the neck portion is slow and the toughness of the neck portion is poor, especially when the shell core portion is made of steel-based material. Molecular roughness occurs, causing problems in the performance of the neck portion, which is undesirable. Further, since the body is long, cooling occurs quickly near the end of the body, which is undesirable because poor welding between the body outer shell and the body core tends to occur. Next, examples will be given and explained. Example 1 An example of manufacturing a roller with a product body diameter of 310φ x body length of 2300mm, a waste diameter of 294φ, a neck diameter of 130φ, one side of the neck length of 121mm, and the other side of the neck length of 285mm. (1) Centrifugal force casting (mold rotation speed 830 rpm, casting temperature
1380℃), outer diameter 322φ, total length 2805mm, inner diameter 270~
A 285φ cylindrical composite outer shell layer was cast. (2) After solidification of the outer shell layer, the mold is stood vertically as a stationary mold, and the core member is poured from the top at a temperature of 1370°C.
A cylindrical composite material was created by casting at ℃. (3) After the cylindrical composite material was subjected to strain relief heat treatment, it was machined to obtain a product roller. (4) The components and hardness of the outer shell layer and the core of the roller were as shown in Table 1. Example 2 An example of manufacturing a roller with a product body diameter of 280φ x body length of 1727mm, a waste diameter of 256φ, a neck diameter of 125φ, one side of the neck length of 152mm, and the other side of the neck length of 310mm. (1) Centrifugal force casting (mold rotation speed 875 rpm, casting temperature
1410℃), outer diameter 296φ, total length 2290mm, inner diameter 135~
An outer shell layer of 145φ cylindrical composite material was cast. (2) After the outer shell layer solidifies, the mold is stood vertically to form a stationary mold, and the core member is poured from the top at a temperature of 1490°C.
A cylindrical composite material was created by casting at ℃. (3) The cylindrical composite material was subjected to high-temperature heat treatment, and after rough processing, only the body portion was normalized and machined to the dimensions of a product roller. (4) The components and hardness of the outer shell layer and the core of the roller were as shown in Table 2.

【table】

[Table] As described above, according to the roller manufacturing method of the present invention, the body diameter and overall length of the target composite casting roller, which has an elongated body and a relatively short neck portion compared to the body length, can be obtained. - Since a long cylindrical composite material is cast and then the desired composite casting roller is cut out from the cylindrical composite material, the number of molding and processing steps during casting is reduced, making it economical. Above, the dynamic balance of the rollers is also good. Furthermore, even if poor welding occurs at the ends, which tends to occur with small-diameter long composite materials, this portion is scraped off and does not remain in the final product. Furthermore, since the neck portion is also machined out from the body core member, it has good toughness. Of course, since the outer shell layer and the core part of the composite roller according to the present invention are welded and integrated by casting, there is no need to worry about strength even if it is used up to the scrap diameter, and there is no need to worry about the strength when it is used up to the scrap diameter. Excessive tensile stress, which is caused by mechanical problems and causes cracks in the roller, does not occur on the inner surface of the roller barrel, resulting in a long life.

[Brief explanation of drawings]

FIG. 1 is an external view of a roller to which the present invention is applied;
Figures 2 and 3 are cross-sectional views showing the structure of a conventional roller, Figure 4 is a cross-sectional view showing the structure of the roller of the present invention, and Figure 5 is a cross-section of a cylindrical composite material that is the material of the roller of the present invention. FIG. 6 shows a cross-sectional view of a conventional centrifugal casting machine mold for manufacturing composite rolls. 1, 12... Torso, 2, 3, 15, 16... Neck part, 13... Torso outer shell layer, 14... Trunk core, 1
7...Cylindrical composite material, 18...Outer shell layer, 19...
core.

Claims (1)

[Claims] 1. An outer shell layer of a cylindrical composite material having a diameter and length slightly larger than the body diameter and overall length of the target roller is centrifugally cast, and then the core and body parts of the target roller are cast by centrifugal force. The core of the cylindrical composite material, which will become the neck part, is cast.
After metallurgically welding and integrating with the outer shell layer, the cylindrical composite material is machined to have a body diameter: D ₁ and a waste diameter:
_D2 , neck diameter: Dn, trunk length: l, neck length at both ends of the trunk: _l1・_l2 , trunk core diameter: _D3 , _D2 / _D1 =0.7~0.95 _D1 /l= A composite casting roller characterized in that 0.12-0.25 Dn/ _D1 = 0.3-0.55 _l1 /l or _l2 /l = 0.05-0.20 _D3 / _D1 = 0.55-0.70 Dn< _D3 < _D2 . manufacturing method.