JPH02153045A - Hardened roll for rolling and rolling mill - Google Patents

Abstract

PURPOSE:To manufacture the title roll having high hardness and excellent wear resistance by executing cladding by welding of a high carbon alloy steel having specific compsn. to the surface of a steel core material having toughness by an electroslag remelting method, subjecting it to diffusion annealing, thereafter subjecting the surface to mechanical working and thereafter to heat treatment. CONSTITUTION:A columnar body 42 made of a bearing steel forming a core material for a rolling roll is placed in a water cooled mold 46 and a pipe-shaped consumable electrode 43 for the formation of the outer layer part of the rolling roll contg., by weight, 0.8 to 1.0% C, 0.6 to 1.5% Si, 0.6 to 1.5% Mn, 0.5 to 3% Ni, 3 to 4.5% Cr, 7.5 to 8.5% Mo, 1 to 1.5% W, 0.8 to 1.5% V and 6 to 7.5% Co, satisfying 16%<=2Mo+W<=19% and 3.5%<=10 (Mn+Ni)-Co<=39% and the balance Fe is immersed into molten slag 44, which is integrated by welding onto the surface of the core material 42 made of a steel by an electroslag remelting method. It is subjected to diffusion annealing at 1,150 to 1,230 deg.C and is thereafter subjected to hot constrained casting, hardening and tempering, by which a composite roll for rolling having high hardness and excellent wear resistance of the surface layer can be manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides a rolling quench roll made of high hardness and wear-resistant material with f$υ, especially a thick roll that is applicable to both cold and hot rolling. Regarding the snout roll.

[Conventional technology]

Conventionally, the work rolls of cold rolling mills are made of Cr, Mo, W.
.

(2) A high-speed tool shoulder containing CO, etc. is used. For example, JI8 standard 8KHff9 (C1~1.15
%, Cr'', 5~4.5%, Mo9~10%,
Wl, 2-1.9%, VQ, 9-1.4%, Co
7.5~&5%, 5%, Mn0.5%, Mn
The remaining Fe (14% or less) is Mo-based high speed steel), and this composition is characterized by high hardness and excellent grindability. However, due to the large amount of Cotk, when it comes to large pieces with a diameter of 40 mm or more, the cooling rate is 4 mm, making it impossible to obtain sufficient hardness through quenching and tempering, which poses a particular problem in terms of hardenability. Ta.

In order to increase the hardness, it is possible to increase the hardness to some extent by raising the quenching temperature and forcibly cooling it, but this often causes cracks to occur. Furthermore, if an attempt is made to dissolve the alloying elements into the matrix at the entire quenching temperature, the surface will melt, which will cause cracks to occur.

On the other hand, since CO increases the quenching temperature, the crystal grains become coarser, which deteriorates the toughness and hardenability, making it unsuitable as a roll material for large objects.

[The problem that the invention attempts to solve]

The materials according to the prior art described above have poor hardenability and cannot obtain sufficient hardness, and are particularly unsuitable for use in large rolls with a diameter of 40W or more.

An object of the present invention is to solve the problems of the prior art and provide a material with significantly improved hardenability and excellent hardness, wear resistance, and toughness, and a rolling roll using the same. .

[Means to solve the problem]

As a method to solve the above-mentioned problems with hardenability, the present inventors have determined that the various properties of the low rho material are lowered than those of conventional materials within a range that does not cause drift 'a. By adding Mn and N1, which increase hardenability, and combining an appropriate amount of Co, the hardenability can be sufficiently hardened even with air cooling, and the hardenability is significantly improved, making it possible to use it for rolls for large objects. We have discovered a material that has high hardness and improved wear resistance and toughness by +1114, and completed the present invention.

That is, in the present invention, Cα8-19, SiQ, 6
~1.5%, Mn a6~1.5%, N1 α5~
3%, CrS~4.5%, Mo7.5~IL5
x%W1~1.5%, VQ, 8~1.5%, Co
It is a high hardness, wear-resistant material characterized by comprising 6 to 7.5%, the balance consisting of Fe and unavoidable impurities, and
This is a rolling quench roll using the material.

Furthermore, the above composition can be integrally welded to the outside of the core material to form a composite roll, and heat treatment is also possible. Also, 1
After quenching from 075 to 1220°C, high tempering at 500 to 650°C results in a hard MC type, pigeon C type, and retained austenite metal me, resulting in a high hardness of HRC 65.3 or higher. , abrasion resistant and high toughness can be obtained.

The roll of the present invention is used for rolling with a diameter of 40 mm or more and is installed in a 4-layer rolling mill, a 6-row rolling mill, and a multi-stage rolling mill consisting of a pair of working rows, an intermediate roll, and a reinforcing row. Served as a roll.

The present invention will be explained in detail below.

In the high hardness, 111it II wear material of the present invention, t
At ta%, Cα8-1%, 5iCL6-1.5%, Mn[
L6~1.5%, Ni[15~3%, Cr5~4.5%
, M.

7.5~&5%, W1~1.5%, V [18~1.
With a composition consisting of 5% Co, 6-15% balance Fe and unavoidable impurities, C and Ma +
-1 was reduced by about a2% of Ca and about 1.5% of Mo.

In particular, it is certain that CO has a negative effect on hardenability, so it was reduced by 1 to 1.5%. This was aimed at increasing the cooling rate to prevent pearlite from crystallizing during the first quenching process. Furthermore, in order to increase hardenability, Mn and Nili were added in a range of 5 to 3%, and the amount of Co was combined in a range of 6 to 15%. That is,
The relationship between Mn, Ni, and Co is 55×10 (Mn +
In the range of Ni ) -Co < 39, the start time of pearlite due to constant temperature change is extended by about 20 times to the longer side,
Sufficient hardness can be obtained even with air cooling, which greatly improves hardenability and works effectively. In addition, in hardenability tests by quenching and tempering, the hardenability was improved by about twice as much.

Next, carbides of Mo and W are precipitated by the bending treatment to increase the hardness. The preferred composition of Mo and W is 16≦2
It is in the range of Mo+W≦19 and has a high hardness of HRC65.3 or higher. In addition, toughness was improved due to the metal #A woven fabric of martensite and retained austenite in the matrix. In particular, by adding Mn and N1 and combining Co,
Since 5 to 20% of residual austenite remains during tempering, toughness is increased. Furthermore, Mn, Ni and C
The combination of O provides high hardness without decreasing s; resistance 14!
Since wear resistance and high toughness are obtained, the effect becomes even more effective.

Next, the reasons for limiting each component of high-speed tool steel are as follows.

C is partially dissolved in the matrix in the quenched state, and the rest is Mo, W+Cr
, V, etc. to form double carbides. It is the element that most influences the properties of high-speed tool steel. If the C content is too low, there will be little secondary hardening; on the other hand, if it is too high, the melting point will drop, and if the quenching temperature is not lowered, a eutectic structure will occur, resulting in brittleness. From this detailed study, we found that if the C content is less than α8, there is less C to form carbide, and if it is more than 1%, the toughness deteriorates, so the optimal range is [18 to 1%, and sufficient shafting is required. has become clear.

Mn is an element that is necessarily included and does not need to be specifically defined, but the amount added is usually 14% or less.

In this study, MnIk'f was set at 0.6 to 1.5%.

The basis for this is that Mn is an element that contributes to improving hardenability [1,
If it is less than 6%, the effect is small, and if it is more than 1.5%, retained austenite circles increase and become stable, and no significant increase in hardness is observed. Also, cracks in the casting tend to occur, so 0.
6 to 5% is sufficient. The combination of N1 and CO increases the effect.

N1 makes the metal group me fine and dissolves into austenite and fezite to strengthen the base. Also, Cr and Mo
It coexists with the steel to increase hardenability, strengthen the matrix, and improve toughness and fqi resistance.
Improve wear resistance. If it is less than a and S%, the above characteristics will not be exhibited, and if it exceeds 3X, austenite will remain and hardness will not be achieved. The combination of Mn and CO can provide even greater effects on hardenability and toughness. 15-3%
is sufficient, and CO does not form carbides and is mostly dissolved in the matrix. CO increases the solubility of C in F6 and increases the amount of solid solution in the IS matrix of carbides, thereby increasing tempering hardness and high hardness. However, it tends to promote carbide segregation and make it brittle. It also increases decarburization, raises the melting point,
There is a tendency to increase residual J austenite. The coexistence of Mn and N1 improves hardenability and is an element that increases toughness without reducing hardness. , the path works well at 6-15%, but at least, at most, the above characteristics
I don't define life.

A part of Mo combines with C to form an M@C type carbide, and the remaining part is solidly dissolved in the base and increases hardness through a secondary hardening phenomenon (tempering). In addition, by high temperature tempering, M,
C-type carbide is precipitated to improve hardness and wear resistance. If it is less than 15%, the hardness and purity will decrease, and if it is more than 85%, Mo carbide will crystallize in a network shape and the toughness will decrease. That path is effective at 7.5~&5%.

Similar to Mo, W partially combines with C to form M and C type carbides, and the remaining part is solidly dissolved in the matrix to form a dense martensitic structure, resulting in υM and C due to the secondary hardening phenomenon. Carbides are precipitated, resulting in high hardness and wear resistance. 1
~1.5% works well. There are 16 between Mo and W
≦2 Mo + "IJ≦19, and in this range high hardness and wear resistance are exhibited.

Cr is an element that combines with C to crystallize Cr carbide and contributes to the wear resistance. 3~&5% is sufficient.

V combines with C to form extremely hard MC type carbide, and 1
Increases wear resistance. On the other hand, it makes grinding difficult. ■
Carbide is difficult to form a solid solution at high temperatures and hinders the growth of crystal grains.

In addition, since the bond with C is strong, the quenching force is obvious, and the side of C dissolved in the matrix is strongly influenced by V. In order to obtain suitable quenching and tempering hardness, a certain quantitative relationship between C and V is required.

Now, 08~1.5% is sufficient for the 1ω elbow, and 1
If it is less than 8%, the heat treatment effect will be unstable, and if it is too much, grindability and melting work will be difficult. It is clear that there is no problem up to t5%.

Sl is also classified as a common element in steelmaking and refining.
It is a component that is unavoidably included in rq.

No. 11 is usually only added for the purpose of deoxidizing, and the content is 14% or less. However, in high-speed variable tool steel, s
Addition of 1 promotes secondary hardening by tempering and improves hardness, wear resistance, and toughness. Therefore, the desirable range for the acid content is 0.6 to 1.5x.

In addition, P, which is an impurity fundamentally contained in non-ciT,
3. Cu, Pb, and N will be explained.

P is an element that segregates in Cu, causing quench cracking,
He becomes a prisoner of Kyoto such as Hizumi. Also, since it significantly increases brittleness, there is usually no problem if it is less than 11%.

Although they are harmful elements like 5Vip, MnS, Tie,
In order to create a form with as little harm as possible, it is sufficient that it is 11% or less.

Cu is an element that contributes to #fineness of steel, but it also causes cracks during forging. If cL is 1% or less, there is no particular harm.

Pb aggregates with MnS and other inclusions.

It has a tendency to gather between dendritic branches, and when added in a large amount, it impairs gloss workability. There is no problem if it is below 11%.

N is similar to C in that it strongly stabilizes the austenite structure. If the amount is 0.1%, there is little harm.

Next, in the method for manufacturing a rolling quench roll of the present invention, steel having sufficient strength and toughness is used as a core material, and a pole of consumable material 1 having the composition of the present invention is placed on the outside of the core material. By using the V-cutrosg remelting method, the outer periphery of the core material and the consumable wire are melted and sequentially solidified to form the outer part, so that the boundary part is sound and free of defects such as unwelded parts and micro cavities. A good joint can be obtained. Therefore, in the present invention, it is possible to heat-treat a composite row y in which an elliptical core material and an outer member are integrated, and the hardness can be reduced even if high hardness, 1## abrasion resistance, and appropriate retained austenite are present. It is possible to manufacture composite rolls with high toughness without having to

4 supported by a pair of work rolls and a reinforcing row.
A 6-type rolling mill with an intermediate roll between the upper and lower pairs of work rolls and a reinforcing roll, and a 6-type rolling mill that allows the intermediate roll to move, and a pair of work rolls, an intermediate roll, and a reinforcing roll. The rolling quench roll of the present invention can be incorporated and used as each roll of a multi-rotation rolling mill or the like.

〔Example〕

Practical examples of the present invention will be explained below using FIGS. 1 to 11, but the present invention is not limited to these examples.

Example [1] Table 1 shows the chemical composition of a further example specifically showing the addition of C, Mo, Co, Mn, and Ni. In Table 1, 15 is a conventional high-speed tool steel with a composition of υ higher than that of the present invention.
, Mo and CO become high. 8 to 14 are made of comparative material. 8 has Mo and Wfi added equally, and N
This is a composition that does not contain 1. 9 is high Mo, high Mn
, the composition is high in CO and does not contain N1. Nos. 10 and 11 have compositions in which Mn, Ni, and ii are outside the scope of the claims. 12 is high in Ni, Co,
This is a composition in which Mn is not added. 13 is Mn and Co
This is a composition in which both are low and N1 is not added. 14 is Mn1! :The composition is high in CO. 1 to 7 indicate the composition of the present invention, Mo and W are 16≦2 Mo + W
It is a composition in which the relationship between Mn, Ni and CO satisfies the following formula: 55≦10 (Mn+Ni)-Co≦39.

The sample was melted in a high-frequency melting furnace and cast into a mold to produce a steel ingot. One block after insulating is 880″QX10h → 700℃
x5h-4 furnace cooling annealing, heat treatment hardness: 11
[Abrasion test, bending test and hardenability test were conducted.

Table 2 shows the test results. The heat treatment hardness was measured using a Rock Uni hardness tester (HRC) using a 15i square test piece.

Heat treatment was performed for each sample at 1150"CX1h → after air cooling, 50"
Repeat the cycle of 0°C x 1h → air cooling 5 times to reduce the hardness to 11
tl was determined. Conventional material 15 shows straightness of HRC67. Comparative materials 8 to 14 all failed to obtain bs~645L, and had Mn, Ni, and c.

The hardness is low because the balance with the amount is poor.

Inventive materials 1 to 7 all had good hardness of 68 to 69. The composition of the present invention reduced C, Mo, Co filtration while adding Mn, Ni. Figure 1 is M
It is a graph showing the relationship between the amounts of n, Ni, and Co and hardness.

No. 291 in Table 2 shows the wear loss by Ken 4 type military wear test. The test method was to put an emery vapor on a TF diameter Zoam turntable rotating at 60 rpm, and place a diameter 1. Loading 800 Brs test pieces? The test method is to apply pressure with a pressure of 1 g for 2 minutes and 20 seconds.

The difference of 1 note after 11M of the test was used as the 1st grade, and the 1st abrasion resistance was compared. The 11i weight loss of conventional material 15 shows a value of 7 & 9■, which indicates an abrasion loss between the present invention material and the comparative material. Comparison materials 8 to 14 have a wear area of 82.1 to 853 cape,
Europe is on the rise. Materials 1 to 7 of the present invention are Jl! It is clear that the loss of l is small and that it exhibits excellent wear. Figure 2 shows Mn, tri, and C.

It is a graph showing the relationship between amount and wear loss.

Nos. 5 and 4 M4 in Table 2 show the results of static bending tests for toughness evaluation. The dimensions of the test piece were 4 mm in thickness, 5 mm in width, 55 mm in length, and 14140 m in distance between the supporting points. Conventional material 15 with target value
The transverse rupture strength was 105 "7 m" and the amount of deflection was 15 m.

FIG. 3 is a graph showing the relationship between Mn, Ni, Co11 and transverse rupture strength. It became clear that all of the present invention materials 1 to 7 exhibited high toughness values, about 1.5 times that of the conventional materials. Figure 4 shows the material of the present invention (1150°C
A%C, 500°C x 1h → A%C 5 times), comparative material (11
50°C x 1h → AC, 500°C x 1h - + AC 5 times),
Conventional material (1150℃ x 1h-+A, C, 500℃ x 1h
4A.

05) is a graph showing the amount of retained austenite.

As is clear from this figure, the comparative and conventional materials have almost no retained austenite, but the inventive material has 5 to 20% residual austenite, and maintains high toughness despite its high hardness. It is clear that there are

Table 2, No. 5!1lIl shows the results of the hardenability test. The test method was to heat a test piece with a diameter of 65 m at 1150°Q for 1 h → air cooling, and then repeat the cycle /l / of soO°C x 1 h → air cooling 5 times. The hardness from the surface after heat treatment was measured, and the hardenability was evaluated from the distance at which the hardness began to decrease. The hardness of conventional materials decreases from the 15-degree position. The hardness of all comparative materials decreases from a position of 10 to 16-. Inventive materials 1 to 7 are 28 to 30
It is clear that the hardness does not decrease to the level of hardness and the hardenability is excellent. Figure @5 is a graph illustrating the relationship between Mn, Ni, Co and hardenability. It has become clear that the hardenability of the material of the present invention is approximately twice as good as that of the conventional material.

Table 1 Table 2 Example [2] Using composition 6 of the invention material shown in Table 5, work rolls for a Type 4 rolling mill were produced. Figure 6 shows the roll configuration of the Type 4 rolling mill. The upper and lower pair of working rows /l/22.23 that directly roll the rolled material 21 are reinforcing rows A'24.2.
It is supported by 5. 26°26' is rolling load 27,
27' indicates the roll pending force.

The work rolls in Table 5 were manufactured using a machine V ctroslag remelting device shown in Figure 8g7, and a steel core material 42 with a diameter of 200 m and a height of 1500 m was placed inside a water-cooled chamber with a diameter of 320 m and a height of 730 m. (bearing steel) was installed on the starting board 45, and the outer material 41 containing Mn and N1 of the present invention material was placed on the starting plate 45 with an inner diameter of 235 mm.
m, outer diameter 280 m cylindrical wear +
The integrity of the joint boundary was checked. the result,
It was confirmed that the outer layer was completely welded and integrated. In addition, the jA mass after melting was cut into cross-sectional shapes and the appearance due to the macro-m weave was observed. No internal defects such as micro cavities were found in the joints of the macro-kumishi. Therefore, even if high-speed rolling, high pressure reduction, and high load rolling are performed, it is predicted that the peeling phenomenon from the joint boundary will not occur.

The steel ingot after melting was diffusion annealed at 1175° C. for 15 hours and machined to a diameter of 300 w x length of 700 mm.

Next, heat treatment was performed for both the inventive material and the conventional material by quenching from 115°C, followed by air cooling at 500°C for 1 hour, which was repeated 5 times. The hardness of the roll surface of the conventional material is Hm 91 (H
RC66). The material of the present invention does not generate cracks during swallow treatment, and the roll surface hardness is Haqs (HRc6as
), and it is clear that it is an excellent material for AtL type rolling mill industry rolls.

Example [3] Using composition 5 of the present invention material shown in Table 4, work rolls for a 6-direct rolling mill were produced. The low IV configuration of the Type 6 rolling mill is shown in FIG. The upper and lower pair of working rows A/22 and 23 that directly compress the rolled material 21 are the roll housing 3 Q
, 30' metal chock held within 28, 2
8' and 29, 29'. The structure allows for easy bending of work rolls. A pair of upper and lower intermediate rows A in contact with the work rolls 22 and 25
/31.32 is arranged so as to be located approximately on the same center line as the upper and lower working rows /1/22.23. This intermediate roll 31° 32 is reinforced with two pieces of wood each on the upper and lower sides III-Iv.
24 and 25.

8g 4 table work q-μ is made by melting a steel ingot melted in a high frequency melting furnace at 88
After two-stage annealing of 0°C x 10 hours → 700°C x sh → furnace cooling, diffusion annealing was performed at 1175°C x 15 hours followed by furnace cooling. After diffusion annealing, hot restraint forging is performed to reduce the forging temperature to 10
Diameter 170w x length 10 in the temperature range of 50 to 1150℃
00m forged.

When the forging temperature exceeds 1150°C, decarburization and oxidation become intense, causing single cracks to occur. At temperatures below 1050°C, forging becomes difficult because the deformation caused by forging is small. After forging, it was annealed and machined into a piece with a diameter of 155 m and a length of 950 m, and was inspected using magnetic flaw detection and dyeing tests, which revealed no defects.

The heat treatment was performed by quenching from 1150°C, followed by heating at 500°C for 1 hour and then air cooling, which was repeated 5 times. As a result, the hardness of the roll surface was determined to be FT898 (HR) by Rock Uni hardness tester CI (RC).
A hardness of C-6a5) was obtained. , Figure 9 shows the hardenability.As is clear from the figure, the hardness of the conventional material starts to decrease from about 15+w, but the hardness of the inventive material starts to decrease from about 30-w. It is clear that the material of the present invention improves the hardenability by about twice as much, and it is clear that it exhibits excellent performance as a work roll for a 6-ton rolling mill.

Example [4] Using composition 2 of the present invention material shown in Table 5, a work roll for a multi-stage cold rolling mill was produced. Row p$ of multi-high rolling mill
The structure is shown in Figure 10. 21 is a rolled material, 22, 22'
are work rolls, 31 and 31' are first intermediate rolls that are in direct contact with the work rolls, and 32 and 32' are first intermediate rolls 3.
1, 51' and a second intermediate roll in contact with 35, 55'.
is a backup bearing roll in contact with the second intermediate roll lVS2, 52', and so and so' are roll housings.

Table 5 The method for manufacturing work rolls is as follows: A steel ingot melted in a high-frequency melting furnace is annealed in two stages: 880°C x 10 hours → 700°C x sh → Furnace cooling, and then kept at 1175°C for 15 hours to undergo furnace cooling diffusion annealing. I did it. After diffusion annealing, hot restrained forging is carried out at a temperature range of 1050 to 1150°C for a diameter of 80 #ll.
Forged to l x length f200m. Forging temperature is 1175
If the temperature exceeds ℃, decarburization and oxidation will be severe and cracks will occur.

At temperatures below 1050°C, forging becomes difficult because the deformation caused by forging is small. After forging and annealing, the diameter is 701.
A piece of 10 m in length was machined and inspected by magnetic flaw detection and dyeing tests, which revealed no defects.

The heat treatment was repeated 5 times from 1150"C to 500"C after quenching and then air cooling. As a result, a high hardness of the roll surface with a hardness of Ha99 (RRC69) was obtained.

FIG. 11 shows the hardenability results of the present invention material and the conventional material. While the conventional material starts to lose its hardness from 15m+, the material of the present invention does not lose hardness almost all the way to the center, and has excellent hardenability, making it a suitable material for work rolls in multi-stage rolling mills. One thing is clear.

[Young fruit of invention]

According to the present invention, the obtained high hardness, wear-resistant material has hardenability more than twice as high as that of conventional materials, and has high hardness without any decrease in toughness (on the contrary, it has a hardness of 1.5 The quench roll for rolling produced from this is suitable as a work roll for a four-roll type, a six-roll type, and a multi-high type rolling mill.

Next, in the steel ingot produced by the electroslag remelting method, the core material and outer material are welded together, so no microcavities are generated at the joint at the boundary, so M! IJM processing was possible, and a hardness of H1197 (HRC68) or higher was obtained. Therefore, the life of the working row can be greatly extended, and the effect is extremely large.

[Brief explanation of the drawing]

Figure 1 is a graph showing the relationship between Mn, Ni, and Co and hardness. Figure 2 is a graph showing the relationship between Mn, Ni, and Co amounts and wear loss. Figure 3 is a graph showing the relationship between Mn, Ni, and Co1k and bending. Graph showing the relationship of forces, 8g4 diagram is a graph showing retained austenite-Europe, 5th
The figure is a graph showing the relationship between the amounts of Mn, Ni, and Co and hardenability. Figure 6 is a schematic sectional view showing the roll configuration of a 4-type rolling mill. Figure 7 is a schematic sectional view of an electroslag remelting device. FIG. 8 is a schematic sectional view showing the roll configuration of a rolling mill of type 6. Figure 9 is a graph showing the relationship between hardenability and hardness, Figure 10 is a schematic sectional view showing the row/I/#4 configuration of a multi-stage rolling mill, and Figure 11 is the relationship between hardenability and hardness. This is a graph showing. 1-15...Materials corresponding to 1-15 in Table 1, 21
... Rolled material, 22.23 ... Work roll, 24.2
5... Reinforcement roll, 31, 32... Intermediate roll, 5
3... Upper intermediate roll movement, 54... Lower intermediate roll movement, 41... Outer 1.42... Core material, 45...
Electrode pipe for outer layer, 44... Contaminant molten slag, 45...
Start board, 46...Water-cooled Chiang type, 47...Oral surface plate, 48...Carbon brush

Claims (1)

[Claims] 1. In weight%, C0.8-1%, Si0.6-1.5%
, Mn0.6-1.5%, Ni0.5-3%, Cr5-
4.5%, Mo7.5-8.5%, W1-1.5%, V
A high hardness, wear-resistant material characterized by comprising 0.8 to 1.5% Co, 6 to 7.5% Co, and the balance consisting of Fe and unavoidable impurities. 2. In the high hardness, wear-resistant material according to claim 1, Mo
A high hardness, wear-resistant material characterized by having a relationship of 16≦2Mo+W≦19 between and W. 3. In the high hardness, wear-resistant material according to claim 1, Mn
, 3.5≦10(Mn+Ni)-C between Ni and Co.
A high hardness, wear-resistant material characterized by having a relationship of o≦39. 4. In weight%, C0.8-1%, Si0.6-1.5%
, Mn0.6-1.5%, Ni0.5-3%, Cr3-
4.5%, Mo7.5-8.5%, W1-1.5%, V
0.8~1.5%, Co6~7.5%, the balance is Fe and unavoidable impurities, and the base structure is M_6C type, MC type, M_7C_3 type, M_2_3 in martensite.
A high-hardness, wear-resistant material characterized by a metal structure with C_6 type carbide and retained austenite. 5. In weight%, C0.8-1%, Si0.6-1.5%
, Mn0.6-1.5%, Ni0.5-3%, Cr3-
4.5%, Mo7.5-8.5%, W1-1.5%, V
A quenching roll for rolling, characterized in that it consists of 0.8 to 1.5% Co, 6 to 7.5% Co, the balance being Fe and unavoidable impurities, and has been subjected to heat treatment. 6. In weight%, C0.8-1%, Si0.6-1.5%
, Mn0.6-1.5%, Ni0.5-3%, Cr5-
4.5%, Mo7.5-8.5%, W1-1.5%, V
A quench roll for rolling comprising 0.8 to 1.5% Co, 6 to 7.5% Co, and the balance Fe and unavoidable impurities, and is a heat-treated integral product. 7. In weight%, C0.8-1%, Si0.6-1.5%
, Mn0.6-1.5%, Ni0.5-3%, Cr3-
4.5%, Mo7.5-8.5%, W1-1.5%, V
A high-hardness, wear-resistant material consisting of 0.8-1.5% Co, 6-7.5% Co, and the balance Fe and unavoidable impurities is used for the surface layer of a strong steel core material, and heat treated. A quenching roll for rolling that is a composite product. 8. In the rolling quench roll according to claim 7, the surface hardness is HRC 65.3 or more, and the strength of the core material is 80 kg/mm^
A quenching roll for rolling, characterized in that the hardening roll is 2 or more. 9. The quenching roll for rolling according to any one of claims 5 to 8 is used as one or more of the upper and lower pair of work rolls and reinforcing rolls in a quadruple rolling mill. A four-layer rolling mill. 10. A multi-stage rolling mill characterized in that the quenching roll for rolling according to any one of claims 5 to 8 is used as one or more of a pair of work rolls, an intermediate roll, and a reinforcing roll. . 11. The quenching roll for rolling according to any one of claims 5 to 8 is used in one or more of the upper and lower pair of work rolls, the reinforcing roll, and the intermediate roll between the two in a six-layer rolling mill. A six-layer rolling mill, characterized in that the intermediate roll is movable in the axial direction. 12. The quenching roll for rolling according to any one of claims 5 to 8 is used as one of a pair of upper and lower work rolls, a reinforcing roll, and an intermediate roll between the two in a six-layer rolling mill. A six-layer rolling mill used as described above, characterized in that the intermediate roll can be moved in the axial direction and a roll pending action can be performed. 15. In the method for manufacturing a rolling quench roll according to claim 6, the step of manufacturing a steel ingot, the step of performing hot restraint forging at 1050 to 1150° C. after diffusion annealing at 1150 to 1230° C., and further the step of performing hot restraint forging at 1075 to 1220° C. After quenching at ℃ 500~6
A method for manufacturing a hardened roll for rolling as an integral product, which comprises a process of high temperature tempering at 50°C. 14. In the method for manufacturing a rolling quench roll according to claim 7 or 8, in weight %, C0.8-1%, Si0.6-1
．． 5%, Mn0.6-1.5%, Ni0.5-3%, C
r3~4.5%, Mo7.5~8.5%, W1~1.5
%, V0.8-1.5%, Co6-7.5%, the balance is F
A process of manufacturing a surface layer by overlaying the outer layer of a steel core material by melting a high hardness, wear-resistant material consisting of e and unavoidable impurities as a consumable electrode using the electroslag remelting method, and a machine after diffusion annealing. A method for manufacturing a quenched roll for rolling as a composite product, which consists of a process of applying heat treatment after processing.