TW201625366A - Work roll for scale breaker - Google Patents

Abstract

The objective of the present invention is to provide a highly reliable work roll for scale breakers that includes a body part having high wear resistance and also a shaft part which is less likely to break, and that is capable of ensuring stable life. The present invention achieves said objective by a scale breaker work roll in which a body part 2 is made of a high-speed steel or a semi-high-speed steel, wherein: a shaft insertion part 31 is constituted by fitting a portion of a shaft member 3 made of a material having greater toughness than the high-speed steel or semi-high-speed steel of the body part 2 into a fitting hole 22 opened in each surface 21 on opposite ends of the body part 2; and the body part 2 and each shaft insertion part 31 are integrated.

Description

Method for manufacturing work roll for rust remover and work roll for rust remover

The present invention relates to a work roll for a rust remover, and more particularly to a work roll for a rust remover which greatly improves reliability and life by using materials having respective required characteristics for the dam portion and the shaft portion (hereinafter, Sometimes referred to as "work roll".

During the rolling process of the steel sheet, a coating layer (rust scale) of iron oxide is generated on the surface of the steel sheet due to air oxidation. Such a coating layer (rust scale) is removed (rust removal) by subjecting the steel sheet to a bending process to cause cracking. In the case of rust removal, a tension leveling rust remover is often used at the same time as removing the scale, and the tension leveling rust remover is used to improve the flatness of the sheet.

The tension leveling type rust remover is composed of a plurality of rolls, and includes a work roll and a backup roll, and the work roll is used for physically removing the scale and flattening the steel plate when the steel plate is in contact with the steel plate. This spare roller is used to prevent the deflection of the work roll. In the tension leveling type rust remover, the rolls of the work rolls, the backup rolls, and the like are provided by disposing a plurality of sets of rolls up and down, and the steel sheets are bent and stretched while traveling between the rolls.

Since the work roll is in contact with the traveling steel plate or subjected to tensile stress of a large traveling direction of the steel sheet, it is easily worn, and the performance of removing or flattening the scale is lowered. Therefore, it is sometimes necessary to restore the performance by grinding the surface of the contact portion (the crotch portion) with the steel sheet, or to replace the roller itself with a new one. There are problems such as a decrease in productivity due to the stop of the work line during polishing and exchange, or a cost required for roll exchange.

As a material of a roll which is highly wear-resistant and which can reduce the frequency of grinding or exchange, a technique of using a high-speed steel (high-speed tool steel) having high abrasion resistance is proposed (for example, Patent Document 1). Further, Patent Document 2 proposes a roller having a wear-resistant material layer formed by liquid-phase sintering a powder of a high-speed material on the outer peripheral portion of the steel-based shaft member, that is, the roller system is only in contact with the steel sheet. The part (ankle) is formed of a high speed material.

On the other hand, the work roll is composed of a crotch portion of the center portion and a shaft portion of the narrow end portions of the both end portions. The crotch portion is a portion for contacting the steel sheet to remove the scale to flatten the shaft portion, and the shaft portion is incorporated into a portion of a bearing for controlling the rotational movement of the roller. Usually, the work roll is strongly pulled in the traveling direction of the sheet through the movement, and the central portion is bent in the traveling direction, so that a very large load acts on the shaft portion of the work roll.

The above-mentioned high-speed steel or semi-high-speed steel has high wear resistance and can reduce abrasion caused by contact with the traveling steel plate, and the use of high-speed steel or the like on the surface of the crotch portion can reduce the wear of the crotch portion caused by the wear of the crotch portion. Grinding or roll exchange frequency. However, high-speed steel or semi-high-speed steel has a disadvantage of insufficient toughness. Therefore, in a roll formed of high-speed steel as a whole of a roll of Patent Document 1, since the load is concentrated on the shaft portion of the small diameter, depending on the working conditions, There may be cases where the roller cannot be used due to the breakage of the shaft portion before the roller is worn due to the wear of the crotch. In addition, even if it is a roll like the patent document 2, since the sintering of the high-speed material powder is performed at the high temperature of about 1300 ° C, the coupling part is heated at the time of sintering, and the shaft is heated by the influence of this heating. The Ministry gives damage.

In the case of operation (actuation), the shaft of the work roll is broken. In the next case, the shaft portion cannot be repaired and reused, and the roller that has been broken at the shaft portion must be discarded. At this time, the high-speed steel is expensive, and if the high-speed steel is used as the material roll, it will be discarded due to the breakage of the shaft portion before it becomes a waste diameter that cannot be polished due to wear of the stern portion. Cost considerations will increase waste and cause great losses in cost.

Further, in general, the state of the work rolls is periodically checked at a frequency of once every two weeks. In the case of severe wear of the crotch, the performance is restored by grinding or the work rolls are exchanged. The breakage of the shaft portion may occur from the start of the use of the new work roll, 2 weeks before the start of the use of the new work roll, and since the breakage of the shaft portion is unexpected and suddenly occurs, the device has to be stopped, and therefore, the productivity is lowered. The losses incurred are quite large.

Therefore, by using high-speed steel as the material of the crotch portion, the problem of wear of the crotch portion can be solved. However, due to the breakage of the shaft portion, the productivity is lowered and the cost is increased. Therefore, the material of the work roll is There is still room for improvement.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. Hei 5-196216

Patent Document 2: Japanese Patent Laid-Open Publication No. 2004-250731

The present invention has been made in view of the above-described background art, and an object thereof is to provide a flange portion that is not only in contact with a steel sheet, has high wear resistance, is less likely to cause breakage of a shaft portion, can ensure stable life, and has high reliability. Descaler for cost reduction Work roll.

In order to solve the above problems, the inventors have found through repeated investigations that the above problems can be solved by using a mixed type work roll which uses steels having respective required characteristics in the crotch portion and the shaft portion. And constitute. Specifically, it has been found that by using a work roll in which a crotch portion is formed of a high-speed steel or a semi-high-speed steel having high wear resistance and a shaft portion is formed of a material having high toughness, not only the problem caused by the wear of the crotch portion but also the problem caused by the wear of the crotch portion can be solved. The present invention can be solved by solving the problems caused by the breakage of the shaft portion, extending the life, improving the reliability, and reducing the cost.

That is, the present invention provides a work roll for a rust remover, which is formed of high-speed steel or semi-high-speed steel, and is characterized in that it is embedded in an embedded hole formed in a plane on both end sides of the dam portion, and is embedded in a toughness. One of the shaft members formed of the material of the high-speed steel or the semi-high-speed steel of the crotch portion constitutes a shaft insertion portion, and the crotch portion and the shaft insertion portion are integrally formed.

According to the present invention, it is possible to provide a work roll for a rust remover which is less worn by the stern portion and has fewer failures due to breakage of the shaft portion, has a long life, and is excellent in stability, and solves the above problems and the above problems.

In the case where the shaft portion of the work roll is broken, there is a problem that the work roll must be discarded or the productivity is lowered due to the stop of the apparatus even if the crotch portion can be used. Therefore, the conventional technique cannot sufficiently exhibit wear resistance. The advantages of high-speed high-speed steel. In the work roll of the present invention, high-speed steel or semi-high-speed steel which is resistant to abrasion is used as the material of the crotch portion, and it is difficult to break the shaft portion. Therefore, there is no such thing as the prior art that the shaft is broken before it becomes obsolete due to wear of the ankle. When the work rolls are first discarded, compared with carbon steel, low alloy steel, SUJ2 (high carbon chromium bearing steel), etc., although the cost of steel has increased several times, it can fully play the material of the fierce friction. Extremely superior for so-called high speed steel or semi-high speed steel. In other words, since the breakage of the shaft portion does not become a bottleneck, the work roll can be used repeatedly until the crotch portion is worn until it becomes worn, and the work roll can be used repeatedly, and the exchange frequency of the work roll can be greatly increased. productivity.

Ordinary steels can reduce the hardness to some extent and improve the toughness (tempering treatment) by tempering after the hardness is increased by quenching and the toughness is lowered. The rolls of carbon steel, low-alloy steel, SUJ2, etc., which are used before high-speed steel is used as the material of the rolls, can be improved in strength and toughness of the shaft portion by quenching and tempering treatment. However, tool steels such as high-speed steel or semi-high-speed steel have the property of maintaining high hardness even at the high-temperature tempering temperature of the quenching and tempering treatment, and it is difficult to improve the toughness (secondary hardening phenomenon), so that high-speed steel or a semi-high speed is used. In the case of steel as the material of the shaft portion, the toughness of the shaft portion cannot be improved by the quenching and tempering treatment, so that it is difficult to break. Therefore, by pulling strongly toward the traveling direction of the steel sheet, in particular, the load is concentrated on the shaft portion into which the bearing is incorporated, and the shaft portion is broken.

In the present invention, a hybrid work roll can be provided which is formed of a high-speed steel or a semi-high-speed steel, and a shaft member is formed of a material having a higher toughness than a high-speed steel or a semi-high-speed steel, and then the two are integrated into one body. The shaft portion is resistant to breakage and the wear resistance of the crotch portion is excellent.

In particular, in the present invention, as a method of integrating the crotch portion and the shaft member, it is preferable to perform heat fitting by setting the surface of the crotch portion to about 150 to 400 °C. The heat tight fitting temperature is lower than the tempering temperature (500 to 600 ° C) of the high speed steel or the semi high speed steel forming the crotch portion, and therefore, the heating of the heat tight fitting does not affect the crotch portion. That is, because The temperature at which the tempering of the crotch is integrated with the crotch portion and the shaft member is accidentally matched at the point of the temperature difference, so that it is possible to provide the necessary performance for the crotch portion and the shaft portion, respectively. Work rolls.

As described above, in the present invention, since the wear resistance of the high-speed steel or the semi-high-speed steel of the crotch portion of the work roll can be maintained, and the breakage of the shaft portion is hardly generated, the wear resistance can be sufficiently exhibited, and The advantages of high-speed steel or semi-high-speed steel, which are less frequently used for grinding and exchange, can be used to grind a high-priced steel, that is, high-speed steel or semi-high-speed steel, to a discarded diameter, and the material cost is less wasted. In addition, it can prevent sudden stop of the device caused by the breakage of the shaft, which can greatly improve productivity and reliability.

1‧‧‧Working roller for rust remover

2‧‧‧胴

3‧‧‧Axis components

20‧‧‧ Surface of the head

21‧‧‧ Both sides of the crotch

22‧‧‧ embedded hole

22a‧‧‧Chamfered part of the hole

22L‧‧‧Deep into the hole

22D‧‧‧Diameter of the embedded hole

31‧‧‧Embedded part (shaft insertion part)

31a‧‧‧Chamfered part of the embedded part

31L‧‧‧ Length of the embedded part

31D‧‧‧Diameter of the embedded part

32‧‧‧ protruding part (shaft part)

32L‧‧‧ Length of the protruding part

32D‧‧‧diameter of the protruding part

33‧‧‧The boundary between the embedded part and the protruding part

Fig. 1 is a schematic view showing a state before the crotch portion and the shaft member are integrated (the difference between the diameter 31D of the fitting portion and the diameter 32D of the protruding portion is exaggeratedly drawn).

Fig. 2 is a schematic view showing the roller for rust remover of the present invention in which the dam portion and the shaft member are integrated. The difference between the diameter of the embedded portion and the diameter of the protruding portion is exaggeratedly drawn.

Hereinafter, the present invention will be described, but the present invention is not limited to the embodiments described below, and can be arbitrarily modified.

The work roll 1 for a rust remover of the present invention is a mixed type work roll formed by integrating a crotch portion 2 and a shaft member 3 formed of different materials.

FIG. 1 is a view schematically showing a state before the crotch portion 2 and the shaft member 3 are integrated. There are cases in which the annular crater and the annular projection are present on the peripheral wall of the crotch portion 2, but these are omitted in the drawings. The crotch part 2 is formed of high speed steel or semi-high speed steel, A cylindrical insertion hole 22 is formed in the center portion of the end portion side surface 21 of the crotch portion 2, respectively. The shaft member 3 is formed of a material having a higher toughness than a high-speed steel or a semi-high-speed steel forming a crotch portion, and is composed of an embedded portion 31 and a protruding portion 32. The fitting portion 31 is fitted into the fitting hole 22 of the crotch portion 2 and functions as a portion of the shaft insertion portion 31. The protruding portion 32 is a portion that is not embedded in the fitting hole 22 and is in a state of being exposed, and is a portion that functions as a shaft portion 32 into which a bearing is incorporated when the work roll 1 is used.

As shown schematically in Fig. 2, by the operation of the heat fitting or the like in the state in which the fitting portion (shaft insertion portion) 31 of the shaft member 3 is fitted into the insertion hole 22 of the jaw portion 2, the jaw portion 2 is The shaft insertion portion 31 is integrally formed to complete the work roll 1 for a rust remover of the present invention.

<胴部>

The crotch portion 2 of the work roll of the present invention is formed of high speed steel or semi-high speed steel. High-speed steel or semi-high-speed steel is characterized by a large amount of special metal components such as chromium (Cr), tungsten (W), molybdenum (Mo), and vanadium (V). High-speed steel or semi-high-speed steel is hardened by quenching by the presence of the char of these special metal components, and is excellent in abrasion resistance and corrosion resistance. Therefore, high-speed steel or semi-high-speed steel is suitable as a material for the wear of the crotch portion which is in direct contact with the steel sheet.

The high speed steel is a high speed tool steel of the mark SKH standardized by JIS G4403 of the Japanese Industrial Standards (JIS).

Among them, high-speed steel containing C: 0.8 to 1.3% by weight, Cr: 3 to 5%, Mo: 4 to 7%, W: 4 to 11%, and V: 1 to 5% is particularly suitable for the present invention. Further, in addition to these metal components, the high speed steel used in the present invention may further contain cobalt (Co).

Specific examples of the high speed steel suitable for the present invention include SKH51, SKH52, SKH53, SKH55, and SKH56 of JIS G4403.

Semi-high speed steel (base type high speed steel) has less carbon (C) content than high speed steel, and other alloy components are the same as high speed steel. Semi-high speed steel has the characteristics of toughness and high speed steel.

The size of the crotch portion 2 is appropriately set depending on the type of the rust remover device using the work roll. The length of the crotch portion 2 is not limited and is usually from 100 cm to 400 cm, preferably from 150 cm to 195 cm. The diameter of the crotch portion 2 is not limited and is usually 60 mm to 100 mm, preferably 70 mm to 90 mm.

A cylindrical insertion hole 22 into which one portion (embedded portion 31) of the shaft member 3 is fitted is formed in a central portion of the both end side planes 21 existing on both sides of the crotch portion 2.

The depth of the insertion hole is 22 L, preferably 40 mm or more and 150 mm or less, more preferably 50 mm or more and 100 mm or less, and particularly preferably 55 mm or more and 70 mm or less. If the depth is too shallow, the joint strength between the crotch portion 2 and the shaft insertion portion 31 becomes weak, and cracks may occur at the junction of the joint portions. If it is too deep, the total length of the shaft member 3 becomes long, and only the labor of cutting is increased, and it is not meant that the joint strength between the crotch portion 2 and the shaft insertion portion 31 becomes stronger.

In particular, in the case where the crotch portion 2 and the shaft member 3 are integrally formed by heat fitting, it is necessary to precisely form the insertion hole 22 in consideration of the deformation at the time of contraction, and if the depth 22L of the insertion hole is too deep, the precision machining is changed. It is more difficult, so I don't want the depth to be deep enough. Further, in the case where the depth 22L of the insertion hole is too deep, it is difficult not only to uniformly heat the periphery of the insertion hole 22, but also to reduce the diameter during the insertion of the shaft insertion portion 31, and to increase the insertion only. The possibility to the way. The above problem is too deep for the depth 22L of the embedded hole, and the embedded hole from both ends is connected. The same applies.

The diameter 22D of the fitting hole is appropriately set according to the diameter 31D of the fitting portion of the corresponding shaft member 3, and is preferably 15 mm or more and 40 mm or less, more preferably 20 mm or more and 30 mm or less.

The manufacturing method of the insertion hole 22 is not particularly limited, and a known method can be employed. The production of the insertion hole 22 is preferably performed after the quenching and tempering treatment of the crotch portion 2.

The crotch portion formed of high speed steel or semi-high speed steel is quenched and then tempered.

Preferably, at least the surface 20 of the crotch portion 2 is quenched during the quenching treatment, and after quenching, the crotch portion 2 is tempered at 500 ° C or higher and 600 ° C or lower, and then the shaft member 3 is embedded in the insertion hole 22 . The shaft insertion portion 31 is formed to integrally integrate the flange portion 2 with the shaft insertion portion 31. Further, it is particularly preferable that only the surface of the jaw portion is quenched by induction hardening.

In the case where the crotch portion 2 is a high speed steel, the quenching temperature is preferably 1000 ° C or more and 1350 ° C or less, more preferably 1150 ° C or more and 1250 ° C or less. In the case where the crotch portion 2 is a semi-high speed steel, the quenching temperature is preferably 1000 ° C or more and 1350 ° C or less, more preferably 1050 ° C or more and 1150 ° C or less. High-speed steel or semi-high-speed steel is very hard due to quenching in the above temperature range, thereby improving wear resistance.

The method of quenching the crotch portion 2 is not particularly limited, and it is preferred that only the surface 20 of the crotch portion is quenched by induction hardening. The induction hardening method is a quenching method in which electromagnetic induction is induced by high-frequency electromagnetic waves to heat the surface, and is a quenching method in which only the surface of the steel material is hardened and the inside is maintained to a certain degree of toughness. Since the surface of the crotch portion 2 is in contact with the steel plate as the object to be treated, It is preferred to increase the hardness as much as possible.

On the other hand, in the case where the insertion hole 22 is formed after quenching, the internal hardness is kept low, and the perforation (production) is easy. Further, in order to reduce the influence of deformation when the crotch portion 2 and the shaft member 3 are integrally formed by heat fitting or the like, it is preferable to suppress the risk of crack generation, and it is preferable to maintain a certain degree of toughness inside the crotch portion. For the reason described above, the method in which the hardness of the surface is increased (the toughness is lowered) and the hardness inside is hardly increased (the toughness is hardly lowered), that is, the induction hardening is a method suitable as the quenching method of the crotch portion 2 of the present invention. .

After quenching the crotch portion 2, tempering treatment is performed. The tempering temperature is preferably 500 ° C or more and 600 ° C or less, more preferably 530 ° C or more and 570 ° C or less.

The tempering method of the crotch portion 2 is not particularly limited, and tempering can be carried out in a heating furnace which is usually employed.

The tempering of the crotch portion 2 formed of high speed steel or semi-high speed steel is carried out at a high temperature as described above. In ordinary steel, if tempering is performed, when the toughness reduced by quenching is restored to some extent and the hardness is lowered, since high-speed steel or semi-high-speed steel contains a large amount of Cr, W, Mo, and V, The tempering is carried out at a high temperature as described above to form a stable carbide, and the hardness is increased (secondary hardening phenomenon). However, on the other hand, since high-speed steel or semi-high-speed steel does not increase the toughness due to high-temperature tempering, when high-speed steel or semi-high-speed steel is used as the material of the shaft portion, the shaft cannot be strengthened to prevent breakage. unit. According to the present invention, the disadvantages of such high speed steel or semi-high speed steel can be eliminated.

<axis member>

The shaft member 3 of the work roll of the present invention is formed of a material having a higher toughness than the high speed steel or the semi-high speed steel of the crotch portion 2. The shaft member 3 is composed of an embedded portion 31 and a protruding portion 32 to make. The fitting portion 31 is a portion that is fitted into the fitting hole 22 of the crotch portion 2, and functions as the shaft insertion portion 31 and is integrally formed with the crotch portion 2. The protruding portion 32 is a portion that does not fit into the crotch portion 2 and constitutes a shaft portion, that is, a portion into which a bearing is incorporated when a work roll is used.

In the operation of the rust remover device, the work roll is strongly pulled toward the traveling direction of the traveling steel plate, so the load is concentrated on the shaft portion of the small diameter, so that the shaft portion may be generated in a material having low toughness like high-speed steel. The damage. In the work roll of the present invention, in order to prevent breakage of the shaft portion, the shaft member 3 is formed of a material having a higher toughness than the high-speed steel or the semi-high-speed steel of the crotch portion 2 (in particular, it is integrated with the crotch portion and then functions as a shaft portion). The prominent part of the action 32).

The material of the shaft member 3 must be a material having a toughness higher than that of the high-speed steel or the semi-high-speed steel of the crotch portion 2. As the material of the shaft member 3, the greater the toughness, the better, and the material of the shaft member 3 can be selected in consideration of the cost of the steel material and the ease of acquisition.

Specific examples of the shaft member 3 are chrome molybdenum steel, carbon steel, SUJ2 (high carbon chromium bearing steel), nickel chrome molybdenum steel, and the like. Further, it is more preferable to carry out quenching and tempering treatment such as quenching and tempering.

The chrome-molybdenum steel is a carbon steel material for mechanical construction of the symbol SCM standardized by JIS G4053. Since chrome-molybdenum steel is excellent in hardenability and is less likely to cause a decrease in toughness during tempering, it is often used as a member having a high risk of brittle fracture such as a crankshaft, and is suitable as a material for a shaft portion of a work roll which is highly risky for breakage.

In order to obtain sufficient quenching effect, it is preferable to use a steel having a large carbon content such as SCM435, SCM440, or SCM445 in chrome-molybdenum steel.

The amount of the element other than the carbon steel system C is a steel which is not classified into the alloy steel. In order to obtain sufficient quenching effect, it is preferable to use C% of 0.4% by weight. The above is the material of the shaft member 3. Specific examples of such a carbon steel include S45C and S50C in a carbon steel material for machine structural use standardized by JIS G4051.

Nickel-chromium-molybdenum steel is a carbon steel material for mechanical construction of the symbol SNCM standardized by JIS G4053. In order to increase the toughness more than chromium-molybdenum steel, high-priced nickel (Ni) is added.

In order to obtain sufficient quenching effect, in the nickel-chromium-molybdenum steel, steels having a large carbon content such as SNCM240, SNCM439, and SNCM447 are preferable.

SUJ2 (high carbon chromium bearing steel) is mostly used for materials such as bearings, and is inexpensive. SUJ2 (High Carbon Chromium Bearing Steel) is one of the steel materials used as the material of the roll before the use of high speed steel.

The diameter 31D of the embedded portion of the shaft member 3 and the diameter 32D of the protruding portion may be the same or different. That is, the boundary 33 between the embedded portion 31 and the protruding portion 32 may or may not be discernible before being formed integrally with the crotch portion 2. An example in which the diameter 31D of the embedded portion is larger than the diameter 32D of the protruding portion is illustrated in Fig. 1. By setting such a configuration, after the crotch portion 2 and the shaft insertion portion 31 are integrated, it becomes difficult to cause a step difference at the boundary portion between the shaft insertion portion 31 and the protruding portion 32, and it is less likely to cause stress concentration. The damage caused by the junction. Further, Fig. 1 is a diagram exaggeratingly depicting the difference between the diameter 31D of the embedded portion and the diameter 32D of the protruding portion. Specifically, the difference between the two (32D-31D) is preferably 0.3 mm or more and 5 mm or less, more preferably 0.5 mm or more and 2 mm or less.

Further, in the case where the diameter 31D of the embedded portion is different from the diameter 32D of the protruding portion (the case where the boundary 33 cannot be clearly confirmed), if the boundary 33 is a smooth tapered shape or a large arc shape, it is integrated. It is then more difficult to create a step difference.

The diameter 31D of the fitting portion is substantially the same as the diameter 22D of the fitting hole, and is preferably 15 mm or more and 40 mm or less, more preferably 20 mm or more and 30 mm or less. The length 31L of the fitting portion is substantially the same as the depth 22L of the fitting hole, and is preferably 40 mm or more and 150 mm or less, more preferably 50 mm or more and 100 mm or less, and particularly preferably 55 mm or more and 70 mm or less. Further, in order to reduce stress concentration, it is preferable to carry out chamfering processing at the end portion of the inner side of the insertion hole, and it is particularly preferable to perform round chamfering.

The diameter 32D of the protruding portion is substantially the same as the diameter 31D of the embedded portion, preferably 15 mm or more and 40 mm or less, more preferably 20 mm or more and 30 mm or less. The length of the protruding portion is 32 L, preferably 30 mm or more and 100 mm or less, more preferably 40 mm or more and 80 mm or less, and particularly preferably 50 mm or more and 60 mm or less.

The ratio of the length 31L of the embedded portion to the length 32L of the protruding portion is 31L: 32L, preferably 4:1 to 1:2, more preferably 2:1 to 1:1.

<Integration of the ankle and the shaft member>

The operation of integrally joining the crotch portion 2 and the shaft member 3 (the shaft insertion portion 31) by inserting one of the shaft members 3 into the fitting hole 22 includes heat fitting, welding, brazing, screwing, and the like. However, in the method of screwing, due to stress concentration, there may be cases where the male thread is broken or the shaft portion is broken near the boundary 33. Further, in the method of welding or brazing, the shaft portion may become high temperature, and the toughness may be lowered, the shaft portion may be broken, or the joint strength may be low.

Therefore, it is preferable that one part of the shaft member 3 is fitted into the insertion hole 22 to integrally form the crotch portion 2 and the shaft member 3 (the shaft insertion portion 31), and the heat is tightly fitted, and by embedding the periphery of the hole 22 The temperature is set to 150 ° C or more and 400 ° C or less. The crotch portion 2 and the shaft member 3 (the shaft insertion portion 31) are integrally formed by the heat fitting. The temperature around the insertion hole 22 is more preferably 200 ° C or more and 350 ° C or less, and particularly preferably 250 ° C or more and 300 ° C or less. By setting such a temperature range, the crotch portion 2 and the shaft insertion portion 3 can be sufficiently integrated. The heat-tightening system can be carried out at a lower temperature as described above, so that the shaft portion is not exposed to high temperatures when heated, and further, a portion having a weak local strength like a male thread is not formed, and therefore, it is not easy. Causes damage.

In addition, the above temperature range is lower than the tempering temperature (500-600 ° C) of the high-speed steel or the semi-high-speed steel. Therefore, the influence of the heat of the heat tight fitting does not affect the crotch portion 2, and the friction resistance of the crotch portion 2 is not lowered. . As described above, when the crotch portion 2 and the shaft member 3 are integrally formed by heat fitting, it is possible to integrate at a temperature lower than the tempering temperature of the high speed steel or the semi-high speed steel. That is, in the case where the heat tight fitting is adopted as the integrated method, since the temperature at the time of tempering of the crotch portion is accidentally matched with the temperature at the time of integration of the crotch portion and the shaft member, the nature of the heat tight matching crotch portion does not The effect is exerted so that the effect of the present invention can be exerted, that is, to provide a work roll that maintains the required performance for the crotch portion and the shaft portion, respectively.

In the case where the crotch portion 2 and the shaft insertion portion 31 are integrally formed by thermal fitting, the value of the thermal tightness (the difference between the diameter 31D of the embedded portion and the diameter 22D of the insertion hole) is divided by the diameter 31D of the embedded portion. The heat ratio of the definition is preferably 0.5/1000 or more and 2/1000 or less, more preferably 0.6/1000 or more and 1.8/1000 or less, and particularly preferably 0.7/1000 or more and 1.5/1000 or less. When the lower limit of the heat tight ratio is equal to or higher than the above value, it can be sufficiently fastened, and the portion constituting the shaft member 3 does not fall off. If the upper limit of the heat tight ratio is less than or equal to the above value, there is no distortion due to excessive fastening, and there is no damage. In addition, the heat tightening must be carried out at a temperature to a certain extent, but if the upper limit of the heat tightness ratio is below the above value, the heat tight fitting temperature becomes higher than the tempering temperature of the high speed steel or the semi-high speed steel (500) ~600 ° C) low temperature, so that the present invention can be exerted The effect, that is, the effect of heating when integrated, does not affect the ankle.

Further, in the case of heat tight fitting, the shape of the insertion hole 22 or the shaft insertion portion 31 is previously designed by considering the volume change at the time of expansion and contraction, and after the crotch portion 2 and the shaft insertion portion 31 are integrally formed, it is easy to A structure in which deformation such as a step of the boundary portion between the shaft insertion portion 31 and the protruding portion 32 is hard to be caused is formed, and it is possible to make the shape more difficult to cause breakage. Specifically, as shown in FIG. 1, the chamfered portion 31a is provided at the front end of the fitting portion (shaft insertion portion) 31, or the chamfered portion 22a is provided at the entrance of the fitting hole 22, and is set to be heated (expansion). A structure having a slight gap is produced, which suppresses deformation at the time of contraction.

The work roll for a rust remover of the present invention has high wear resistance of the crotch portion and high toughness of the shaft portion, so that the life is long and the productivity accompanying the stop of the work line can be prevented from being lowered. This is achieved by the above-described operation as an operation of forming the crotch portion and the shaft member from different materials and integrating the crotch portion and the shaft member.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples and comparative examples, but the present invention is not limited to the examples and comparative examples as long as the scope is not exceeded.

[Comparative Example 1]

Two work rolls (first high frequency industrial Co., Ltd.; DHH-511) having a diameter of 80 mm are mounted on a tension leveling type rust remover device, and the steel plate is subjected to rust removal treatment, wherein the part is included The work rolls of the shaft and the whole are formed of high speed steel.

[Example 1]

The cylindrical member having the same configuration as that of the high speed steel used in Comparative Example 1 was quenched at 1200 ° C, and then tempered at 550 ° C. A hole having a diameter of 26 mm and a depth of 80 mm was formed in the plane of the both end sides of the cylindrical member to form a crotch portion. The shaft member was made of chrome molybdenum steel (SCM440). The embedded portion of the shaft member was set to have a diameter of 26.05 mm and a length of 80 mm, and the protruding portion was set to have a diameter of 25 mm and a length of 55 mm. The boundary between the embedded portion and the protruding portion is set to be a smooth tapered shape.

By setting the temperature around the insertion hole of the crotch portion to 300 ° C and thermally fitting the shaft insertion portion of the shaft member into the insertion hole of the crotch portion, the crotch portion and the shaft member are integrated to form the crotch portion and the shaft. A work roll formed of different materials. The heat tightness ratio was 1.9/1000, and it was confirmed by visual observation that there was no step difference between the crotch portion and the shaft portion.

The overall shape of the produced work rolls was substantially the same as that of the work rolls used in Comparative Example 1. In the same manner as in Comparative Example 1, the produced work rolls were attached to a tension leveling type rust remover device, and the steel plate was subjected to a rust removal treatment under the same conditions as in Comparative Example 1.

[Embodiment 2]

In the same manner as in Example 1, except that chrome-molybdenum steel (SCM440) was changed to carbon steel (S45C), work rolls formed of different materials for the crotch portion and the shaft portion were prepared, and the steel plate was subjected to rust removal treatment in continuous operation.

<Results of Examples and Comparative Examples>

In Comparative Example 1, one of the work rolls after 85 hours from the start of the operation The shaft portion is broken at the shaft root and stops. The crotch portion of the work roll was visually confirmed to be slightly damaged, and although it was at least as long as it could be used for grinding, since the shaft portion was broken, it was necessary to exchange a new work roll.

On the other hand, in the first embodiment and the second embodiment, the breakage of the shaft portion was not generated, and the rust removing treatment was smoothly performed. After two weeks from the start of the operation, the state of the work rolls was confirmed as a regular inspection, and no abnormality was observed in the shaft portion. Although it is confirmed that the ankle is slightly damaged, it is still in a usable state. Therefore, start running again.

In the first and second embodiments, the state of the work rolls was confirmed by regular inspection every two weeks thereafter, but the shaft portion was not found to be abnormal. When it is confirmed that there is a peeling or peeling mark on the crotch portion, the same work roll can be used again by grinding the surface of the crotch portion. The grinding of the crotch portion was repeated until the diameter of the crotch portion was 70 mm, which was a discarding diameter. It was used for about one year, but the shaft portion was not damaged at all.

(industrial availability)

Since the work rolls for the rust remover of the present invention have a long life and good productivity, they can be widely used for rolling processing of steel sheets such as steel mills or steel coil centers.

1‧‧‧Working roller for rust remover

2‧‧‧胴

3‧‧‧Axis components

31‧‧‧Embedded part (shaft insertion part)

32‧‧‧ protruding part (shaft part)

Claims (8)

A work roll for a rust remover, wherein the shank portion is formed of high-speed steel or semi-high-speed steel and has a shaft portion, wherein the shaft member is formed of a material having a toughness higher than that of the high-speed steel or the semi-high-speed steel of the shank portion, One of the shaft members is integrally formed with the flange portion in a state in which it is fitted into the insertion hole formed in the plane of the both end sides of the flange portion. A work roll for a rust remover according to claim 1, wherein the shaft member is formed of chrome molybdenum steel, carbon steel, SUJ2 (high carbon chromium bearing steel) or nickel chrome molybdenum steel. The work roll for a rust remover of claim 1, wherein the depth of the insertion hole into which one of the shaft members is partially embedded is 40 mm or more. The work roll for a rust remover according to any one of claims 1 to 3, wherein, in the shaft member, a diameter of an embedded portion embedded in the insertion hole is larger than a diameter of a protruding portion not embedded in the insertion hole and constituting the shaft portion After the crotch portion and the shaft insertion portion are integrally formed, it is difficult to cause a step at the boundary between the fitting portion of the shaft member and the protruding portion. A manufacturing method of a work roll for a rust remover, which is a method for manufacturing a work roll for a rust remover formed of high speed steel or semi-high speed steel, which is characterized in that it is formed in an insertion hole in a plane on both end sides of the dam portion A shaft insertion portion is formed by embedding a portion of the shaft member formed of a material having a higher toughness than the high-speed steel or the semi-high-speed steel of the crotch portion, and the crotch portion and the shaft insertion portion are integrally formed. The method of manufacturing a work roll for a rust remover according to claim 5, wherein the one of the shaft members is partially embedded in the insertion hole to integrally form the dam portion and the shaft insertion portion, which is a heat fit by the embedding The temperature around the hole is set to 150 ° C or more and 400 ° C or less to perform heat tight fitting, and the crotch portion and the shaft insertion portion are integrally formed. A method of manufacturing a work roll for a rust remover according to claim 5 or 6, wherein At least the surface of the crotch portion is quenched, and after the quenching, the crucible portion is tempered at 500 ° C or higher and 600 ° C or lower, and then the shaft member is fitted into the insertion hole to form a shaft insertion portion, thereby forming the crotch portion And the shaft insertion portion is formed integrally. The method for producing a work roll for a rust remover according to claim 7, wherein the surface of the crotch portion is quenched by induction hardening.