JPS5870906A - Composite roll for rolling having double outside layers - Google Patents

Abstract

PURPOSE:To provide a composite roll for rolling which is obtd. by forming the outside shell layer to serve as a working layer in the body part of the roll of two layers of different chemical components and which is usable by transfer successively to stands where the characteristics required for the surfaces of the bodies differ. CONSTITUTION:In the case in which a high alloy chilled material having excellent surface roughening resistance is suited for a stand No. 7, and a high alloy grain material of high cracking resistance and abrasion resistance is suited for stands Nos. 6-4, the 1st outside layer 3 used for rolling with the stand No. 7 is formed of the high alloy chilled material and the 2nd outside layer 4 used for rolling with the stands Nos. 6-4 is formed of the high alloy grain material. With both, the hardness thereof is set at about 75-85 deg. Hs. If the 1st outside layer 3 is used first down to the intended diameter with the stand No. 7 by using such rolls, the remaining 1st outside layer 3 or mixed layers are removed and the 2nd outside layer 4 is used in the stands Nos. 6-4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a composite roll used for rough finishing work rolls in hot strip mills and other rolls for plate rolling. Regarding.

As shown in Figure 1, there are many types of rolls used in sheet rolling that have an outer shell layer (1) and a core (2) made of different materials. These are manufactured by centrifugal casting or hollow casting. This composite roll starts to be used at the indicated maximum outside diameter (new diameter), and when it wears out through use and reaches the scrapping diameter O, it is disposed of. ) is usually formed to a thickness that reaches the waste diameter of 0 and has some margin.

In addition, the method of using rolling rolls includes finishing roll stand hook g-
As in the case of the A-stand, the final stand (Aγ stand) is first installed and used, and when it wears down to a certain outer diameter, it is moved to the next stand (A-stand), and in the same way, AI and Jfa4 stands are used one after another. There are some products that are moved to the next stage and are then disposed of. That is, as shown in FIG. 4, in one finishing stand, the latter four machines are used. In this case, in the final height 7 stand, the rolling reduction is small and the beauty of the product skin is the most important, but on the other hand, in the flat 6 to 4 stands, the rolling reduction is large, and damage to the roll will occur if problems such as squeezing occur. It is also large and causes a lot of wear. In other words, the characteristics required for the body surface of the A7 stand roll and the A6-4 stand roll are different! ? For stands, the main focus is on the beauty of the roll skin, while for flat-to-4 stands, crack resistance, accident resistance, and abrasion resistance against a different abrasion mechanism than for A-size stands are required. Looking at conventional composite rolls used under such conditions, although the required properties differ depending on the stand as described above, it is difficult to use a roll with a single outer shell layer of a constant chemical composition across multiple stands. The reality is that it is. For example, according to the conventional example, Adamite rolls are used for the A4-3 stand work rolls in the first stage, while high-alloy grain mill is used for the A4-7 stand work rolls in the i stage, and in the latter case, the first K
It is customary to install a new roll in the A7 stand, use it sequentially as 71i 6, A5, and A4 as the diameter decreases, and then dispose of it in the A4 stand.

In view of these circumstances, the present invention aims to improve the use performance and lifespan of stands that are used by sequentially transitioning to stands with different characteristics required for the body surface, and to improve the use layer buttons of the body. -f
It is an object of the present invention to provide a rolling composite roll having a new structure formed of two outer layers of To explain the case where it is applied to the purpose of Chilled high-alloy material with excellent surface roughness resistance is suitable for stands, while high-alloy grain material with excellent crack resistance and abrasion resistance is suitable for A6-4 stands.

In this case, in the present invention, as shown in Figure @2, the outer shell layer corresponding to the layer to be used is formed into two layers, the first outer layer (3) and the second outer layer (4), and the outer shell layer is formed into two layers, the first outer layer (3) and the second outer layer (4). The first outer layer (3) to be used is made of a high-alloy chilled material, and the second outer layer (4) to be used in rolling with a blade height of 6 to 4 is made of a high-alloy grain material to form an outer shell. Configure layers. Note that the core material (5) of this composite roll may be made of high-grade cast iron or ductile cast iron as in the past.

Here, high-alloy chilled material generally refers to a base consisting of carbide, bainite, or martensite and no graphite in its structure, and high-alloy grain material refers to a material with a small amount of massive graphite, carbide, and 6-bainite. The hardness of both is Ha 115~8? , and its chemical components are listed below in Part 1! Note that both materials should be heat treated at 300-500°C to remove casting strain and stabilize the matrix structure, but it is sufficient to perform the same heat treatment as conventional rolls. Diameter b of transition from outer layer (3) to second outer layer (4) K
1 The diameter d transitioning from the second outer layer (4) to the core material (6) is shown as having the relationship as shown in FIG. 3 (tl: first outer layer thickness, tl: second outer layer thickness)) .

As a method for manufacturing the above-mentioned book a-ru, it is preferable to use a centrifugal force casting method. In the case of this method, a melting method was developed in which the high-alloy chilled material to be cast as the first outer layer is mixed by a predetermined first outer layer thickness t1% outer diameter machining allowance and later by casting the second outer layer. Cast with casting thickness. When the first outer layer has solidified to #1, the high-base metal grain material to be cast as the second outer layer is cast. In order to ensure a predetermined second outer layer thickness t2, the casting thickness is determined by considering the inner surface erosion equation when casting the core material.

Note that in terms of manufacturing technology for this roll, special attention must be paid to ensuring that the thickness of the first outer layer is as targeted and that the thickness is uniform both in the circumferential direction and in the axial direction.

For this purpose, it is necessary to pay attention to the following points.

(1) Make the thickness of the mold coating agent on the mold more uniform.

(2) Make the casting weight of the first outer layer more accurate. (3) Set the casting temperature of the first outer layer to the target value.

(4) Accurate casting timing of the second outer layer.

(5) Set the casting temperature of the second outer layer to the target value.

(6) The casting of the second outer layer is carried out using a gutter movement method, so that the erosion of the inner surface of the first outer layer is constant in the axial direction.

('y) The number of revolutions of the mold during casting of the second outer layer is set to an appropriate value depending on the casting method.

(8) The core material may be cast in the same manner as the conventional centrifugal casting method.

As mentioned above, regarding the casting of the first outer layer and the second outer layer,
Stricter work control is required compared to traditional centrifugal casting methods.

However, even under the above-mentioned strict working conditions, the boundary between the first outer layer and the second outer layer may not necessarily be concentric with the outer diameter of the product, and a mixed layer of both may not be formed. In some cases, 4I may produce different tissue materials. In such a case, if the first outer layer is used up to the target diameter,
When moving to the front stage stand, the outer diameter of the roll was changed to 5M.
The remaining first outer layer or mixed layer may be removed by turning to a certain extent and used in a stand for the second outer layer.

Next, a case will be described in which the present invention is applied to a roll having a usage mode different from the above example. As shown in Figure 5, in the case of a certain 7-stand mill, the A1 stand requires rough skin resistance, and the Am 7 stand requires wear resistance, rough skin resistance, and dent resistance. High hardness material is required. And Aml in between! For I-stands, material properties intermediate between the two are required. In this case, 7f11, /riHa50-66 for the goose stand
Adamite material of H165-15 and high chromium material are suitable for /I63-S stands, while high-alloy grain materials of around Hs80 and high-chromium materials are suitable for A-17 stands. High alloy chilled material is suitable. Preferred application of the invention to such uses - as an example, jlE1 outer layer +31 in FIG. 2, AI,! The second outer layer (4) is made of a high carbon adamite material of H*55 to F δ which is subjected to rolling on an A, 1-It stand. Alternatively, the mating roll can be made of a high chromium material. That is, in this composite role, A
1 to the most effective way to apply a single a-le skin across the device stand.
The core material (6) K of this composite roll may be selected from high-grade cast iron, ductile cast iron, graphite steel, or the like.

Here, H150-55 adamite material melts, large [
-1 high carbon adamite material has a C content in the range of 1.0 to 1.9% and consists of a small amount of fine carbide and matrix structure, and -1 high carbon adamite material generally has a C content of 1.9 to 2.6%. In the range of %,
The adamite material also consists of a hard base with a lot of carbide, and other W%Wb as required.

Refers to those containing special elements such as V. The term "high chromium material" means one containing about 1O-ja5* of Cr and a large amount of eutectic carbide.The chemical components of each of these materials are shown in Table 2 below.

Although these materials require diffusion heat treatment, skewering, and strain relief heat treatment, the characteristics of each material can be sufficiently maintained by heat treating them in the same manner as conventional rolls.

Table 2 below: Chemical composition (wt%) C8i Mn P 8 Ni
CrM.

In the above section, we have described the case where the stand is transferred from the AX stand to the A3.4 stand and the S stand, but if the usage is reversed from this case, the material of the first outer layer and the second outer layer should be changed. The combinations can be reversed to form the composite roll.

The method of using Maro Cool and examples of material combinations for the first and second outer layers are as shown in Table 11E50 Table 3 Material combinations for the first and second outer layers First outer layer
2nd outer layer How to use B) II-Father~Kinabazuto H-ro~? 6 high chromium I; 112-J
E8, SD) Hs 55 to 6 high chrome H*50
~55 al'w4t's, 4.1l-Jil, 1st 5th
Regarding the roll used in the manner shown in the figure, the above four material combination examples are possible, but among these, IIi A)
, B) is preferred.

In other words, when the first outer layer is made of a high-carbon, high-alloy material as in examples C) and D), when low-carbon adamite material is cast into the second outer layer, C and alloying elements in the first outer layer are There is a risk that it will mix and diffuse into the second outer layer and form a structure with a lot of carbides.
On the other hand, in the case of A1 and aluminum stands, there is a problem of deterioration of roughness resistance when coarse carbides are present in large quantities, and in order to ensure roughness resistance in Al51 stands, a dense structure is particularly required during rapid cooling during casting. This is for the purpose of

Next, referring to FIG. 6, a case will be described in which the present invention is applied to a roll having other usage modes. That is,
FIG. 6 shows an example in which a roll with a new diameter is installed in a 6-high stand and used, and then the roll is sequentially transferred to the previous stand and used up to the AI stand. In this case, A6, II, 4
For stands, the first outer layer (Ill) is made of high-alloy grain material around H180, while for Todoroki, Yuki, and one stand, the second outer layer (4) is made with roughness resistance. It can be formed from a medium alloy grain material of Shi6H-10 to F5.

In this way, in the composite roll according to the present invention, the first outer layer (3) and the second outer layer (4) do not necessarily need to be made of materials with extremely different chemical components; It is also possible to change the structure and hardness by changing only a part of the C content or alloy components in the materials of the series, and to combine them, and these are, of course, included in the present invention.

In addition, various multi-layered rolls have been known in the past to be compared with the present invention, but these rolls are limited to the layers used, such as those in which an intermediate layer is interposed between the outer shell layer and the core material. (from menarche to scrap diameter) are formed of the same material, and the present invention forms the layers used for rolling into two layers, the first outer layer and the second outer layer, which are made of different materials. This is essentially different.

Specific examples of the present invention will be listed and explained below.

<Example 1) 14 Roll manufacturing conditions for the usage shown in Fig. 4 Roll dimensions: 50φ x 1'100', waste volume
650φ 1st outer layer: High alloy chilled material, target thickness '
iR, 511111 2nd outer layer: High alloy grain material, target thickness 3 pieces, 1 core material: High grade cast iron 1st outer layer casting thickness 2'/, 5W Casting weight 85
0 Second outer layer casting thickness GuOM Casting weight 1”840
The thickness of the first outer layer of the product coated cool obtained under the manufacturing conditions of 11 or more was 12 to 15 fi, and the thickness of the second outer layer was 65 to 61 g1f. At this time, the first outer layer is the seventh layer.
As shown in the figure, it shows a completely chilled structure and has a hardness of Hs80.
5 was obtained, -1 The second layer showed a high alloy grain structure as shown in A15 in FIG. 8, and a hardness of H879.8 was obtained, and the desired composite roll was successfully obtained.

In addition, in this roll, after using the first outer layer for one side [1 m+], it is necessary to process the first outer layer to about 6 M in diameter to remove the mixed layer of both.

〈Example 2) Example of manufacturing a roll for the usage mode shown in Fig. 5 (A) Manufacturing conditions Roll dimensions: 760φ x IIyoo', Disposal diameter: 650φ First outer layer: Adamite material, Target thickness: 201M Second outer layer: High carbon adamite material , Target thickness SOW core material: Ductile cast iron 1st outer layer casting thickness S2F2M Casting weight 1”
050 Kp Second outer layer casting thickness 62.5W Casting weight 1T621P1N 1986-70906 (5) The first composite roll of the product obtained under the above manufacturing conditions
The outer layer thickness is 36~31 mm, and the second outer layer thickness is 40~31 mm.
It was 48M. At this time, the first outer layer exhibits a fine structure with excellent skin roughness resistance as shown in Figure 9, and has a hardness of Ha 80-5.
As shown in Figure 10, the -1 second outer layer exhibits a structure with excellent wear resistance with many carbides, and the hardness is H159~
At step 64, the desired composite roll was obtained. Note that this roll is subjected to diffusion heat treatment at 1000° C. after rough processing, followed by air quenching and strain relief heat treatment.

(Example S> Roll manufacturing example (II) using the usage mode shown in FIG. 5 Manufacturing conditions P! is the same as in Example 8. However, the second outer layer is made of a high chromium material as shown below.

Table 6 Roll chemical composition (wtIIli) (Mg:
αo59) The first outer layer thickness of the product composite roll obtained under such manufacturing conditions was 34 to 36 MM, and the second outer layer thickness was 31 to 45j11. At this time, the first outer layer
As shown in Figure 1, it shows a structure with excellent roughness resistance, and the hardness is H-52 to δ, while the outer layer @2 shows a structure of a high chromium material as shown in Figure 12, and the hardness is H-52 to δ. The desired composite roll was obtained from H167 to Hue. Note that this roll was subjected to diffusion heat treatment at 1000° C. after rough processing, followed by spray water cooling heat treatment and strain relief heat treatment.

As described in detail above, the present invention provides a method for rolling work rolls that are sequentially transferred to stands having different characteristics required for the body surface, and that the outer shell corresponding to the layer used in the body is The layer is a first outer layer having different chemical components and 11/E2.
Because it is formed into two outer layers, it is a single roll that can be used in multiple stands with different required characteristics.This type of composite roll is especially useful for improving the surface appearance and dimensions of rolled products. This is of great practical benefit as it contributes to improved accuracy and extended Kct-rule life.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing an example of a conventional composite roll structure, @2
The figure is a cross-sectional view showing an example of a composite roll structure according to the final version, and the mS diagram is an explanatory diagram showing the relationship between the thicknesses of the first and second outer layers with respect to the maximum outer diameter of the body and the waste diameter in the composite roll according to the present invention. 4 to 6 are schematic explanatory diagrams showing how the work roll is used after being transferred to the stand. Figures 7 to 12 are all forward mirror photographs showing the structure of the metal layer obtained in the examples of the present invention, with Figure 7 showing the high alloy chilled material of the first outer layer, and Figure 8 Figure 9 shows the high alloy grain material in the second outer layer, Figure 9 shows the adamite material in the first outer layer, Figure 10 shows the high carbon adamite material in the second outer layer, Figure 11 shows the adamite material in the first outer layer, and Figure 11 shows the adamite material in the first outer layer. The figure shows the high chromium material of the @2 outer layer, respectively. (1)... Outer shell layer, (!l-... Core part, (3)...
First outer layer, (4)...Second outer layer, (Il...Core material. Patent applicant: Kubota Iron Works Co., Ltd. Agent: Patent attorney Yasu 1) Toshio Tobira 45. ．． =f3P1
ノ Pear 1 1 Figure 3 Figure 5 Ab1234567 $2 Figure Ma Figure 4 Figure 6

Claims (1)

[Scope of Claims] 1. In a leak roll for rolling that is used by successively moving to stands with different properties required for the body surface, the outer shell layer corresponding to the layer used in the body part is replaced with a first outer layer having a different chemical composition. A composite roll for rolling comprising two layers: and a second outer layer. 2. The rolling pot metal roll according to claim 1, wherein the first outer layer is made of a material that is compatible with the final stand, while the second outer layer is made of a material that is compatible with the stands before the final stand. 3. The first outer layer is formed of high alloy chilled material, while #!
The rolling equipment roll 04 according to claim 2, wherein the second outer layer is made of high-alloy grain material, the first outer layer is made of a material compatible with the front stage of the finishing stand, while the second outer layer is compatible with the middle stand. A composite roll for rolling according to claim 1, which is formed of a material that is a L The first outer layer is formed of an adamite material, while the second outer layer is formed of a high carbon adamite material.
Composite roll OL for rolling according to claim 1, wherein the first outer layer is formed of an adamite material, while the second outer layer is formed of a high chromium material! ! 1. A combination roll for compaction according to item 4.