JPH0299253A - Assembling type roll for continuous casting slab - Google Patents

Abstract

PURPOSE:To prevent stress concentration at center part to axial direction of outer layer member and to make difficult-to-development of crack by fitting a shaft member arranging grooves for supplying coolant on outer peripheral surface of a barrel part into cylindrical outer layer member made of wear resistant material and executing solid phase junction. CONSTITUTION:The shaft member 32 is fitted into the outer layer member 31 and diffusion junction is executed to both with hot isostatic pressing treatment. On the outer peripheral surface of the barrel part in the shaft member 32, the spiral groove is arranged and plugged at the center part, and a first groove 33 for supplying coolant flowing from the center toward one end of the barrel part and a second groove 34 for supplying coolant flowing toward the other end, are formed. The coolant is at first supplied to the center part of the barrel part to particularly cool the center part heated with a slab. As the outer layer member 31 and the shaft member 32 are integrated by executing the solid phase junction (diffusion junction) with the hot isostatic pressing treatment, the gap is not formed and load is received to both members and the stress concentration is difficult to develop and the crack is difficult to develop.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an assembly type roll used as a pinch roll, a guide roll, etc. used in continuous slab casting equipment.

(Prior Art) Conventionally, there are roughly two types of rolls used as pinch rolls and guide rolls in continuous slab casting machines: solid rolls and assembled rolls. The assembly type roll has a structure as shown in FIG. 6, and a spiral cooling medium feeding groove is formed on the outer peripheral surface of the body of the roll shaft member 52 made of carbon steel for mechanical structure or low alloy steel. (hereinafter referred to as a "groove") 54 is provided, and a cylindrical outer layer member 51 forged from alloy steel or the like with excellent wear resistance is fitted into the shaft member 52. The shaft member 52 and the outer layer member 51 are fixed by welding 60 at the end. Then, the opening of the groove 54 on the outer circumferential surface of the body is closed by the inner circumferential surface 53 of the outer layer member 51, and the cooling medium feeding flow path (hereinafter referred to as "
"flow path". ) 55 are formed.

Further, cooling medium supply and discharge holes (hereinafter referred to as "feeding holes") 58 and 59 are bored at both ends of the shaft member 52 along the axis. A flow path 55 is communicated at both ends of the body. According to this roll, the cooling medium supplied from the supply/discharge hole on one end side of the shaft is guided to the flow path on the inner circumferential surface 53 of the outer layer member, and after cooling the outer layer member 51, the cooling medium is supplied through the supply/discharge hole on the other end side. is discharged from.

(Problem to be Solved by the Invention) However, in the conventional assembly type roll, since the outer layer member 51 is only fixed to the shaft member 52 at both ends, the bending stress applied to the roll is applied to the shaft member 52 of the outer layer member 51. It is easy to concentrate in the center of the direction. Therefore, once a crank occurs in the outer layer member 51, the crank develops quickly and
The outer layer member 51 finally breaks, causing an accident in which the cooling medium is blown out.

Furthermore, since the outer circumferential surface of the central portion of the outer layer member 51 comes into contact with the high-temperature slab, the central portion bulges in the radial outward direction, and as shown in FIG. A gap is created between the outer surface (that is, the outer circumferential surface of the shaft member trunk) and the inner circumferential surface of the outer layer member 51 . In such a state, not only will the flow of the cooling medium become uneven and the cooling effect will be reduced, but if a large load is applied from the slab to the outer layer member 51, a large force will be applied to both ends of the outer layer member 51, causing both ends to become stuck. This may cause the cooling medium to blow out, as described above.

The present invention was made in view of such problems, and an object of the present invention is to provide an assembly type roll for continuous slab casting in which the outer layer member is less likely to be damaged and the cooling effect is similar.

(Means for Solving the Problems) In order to achieve the above object, the assembled roll for continuous slab casting of the present invention has a cylindrical outer layer member 1.31 made of a wear-resistant material, and a strong material made of a tough material. Shaft members 5 and 32 formed thereon and having cooling medium feeding grooves 3, 33 and 34 recessed in the outer circumferential surface of the body are fitted together and solid-state welded.
, 33 and 34 on the outer circumferential surface of the body are the inner circumferential surface of the outer layer member 2.
30 and are closed by the cooling medium feeding channels 4, 35.
36 was formed. And roll shaft member 32
The cooling medium feeding groove 33 on the outer circumferential surface of the body includes a first spiral cooling medium feeding groove 33 extending from the center of the body toward one end of the body, and a first coolant feeding groove 33 extending from the center of the body toward the other end of the body. A cooling medium introduction path 37, 38 is formed from a spiral second cooling medium feeding groove 34, and the first and second cooling medium feeding grooves 34 are provided in the shaft member 32 at the center of the body. By communicating with the first and second discharge passages 39 and 40 provided in the shaft member 32 at the end of the body, the roll outer layer member can be effectively cooled. More effective cooling can be achieved by forming the axial pitch of the cooling medium feeding grooves 33, 34 on the outer circumferential surface of the body to be small in the center region of the body and large in the end regions of the body.

(Function) Since the outer surface of all the peaks 6 on the outer periphery of the body of the roll shaft member 5.32 is solid phase bonded (diffusion bonded) to the inner circumferential surface of the outer layer member by hot isostatic pressure treatment, Expansion in the radial outward direction of the central portion of the outer layer member is always restrained by the outer surface of the peak, and the force applied to the roll can always be borne by both the outer layer member and the shaft member. And, as mentioned above, Yamabe 6
The outer surface and the inner circumferential surface of the outer layer member are solid phase bonded, and the opening of the groove on the outer circumferential surface of the body is closed by the inner circumferential surface of the outer layer member to form a flow path. It can be flowed evenly along the line.

In addition, first and second coolant feeding channels which are not communicated are formed in the inner circumferential surface 30 of the outer layer member from the center of the body toward one end and the other end of the body, respectively, and Since the second flow path is connected to the cooling medium introduction path 37 and 38 provided in the shaft member 32 at the center of the body, the high temperature can be lowered by flowing the cooling medium into the flow path from the center of the body. In the center of the body, which is easily heated by contact with the slab of
It is possible to supply a cooling medium that does not cause a temperature rise, suppress an excessive temperature rise in the center of the body of the outer layer member 31, and make the temperature distribution of the roll outer layer member uniform.

Furthermore, by narrowing the interval between the cooling medium flow paths near the center of the body, excessive temperature rise in the center of the body of the outer layer member 31 is further suppressed, and the temperature distribution of the roll outer layer member is further improved. It can be made uniform.

Therefore, the temperature distribution on the outer circumferential surface of the outer layer member 31 during continuous casting can be maintained more uniformly, so that the radially outward expansion of the axial center portion of the outer layer member 31 can be suppressed.

(Example) Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows the structure of a prefabricated roll for continuous slab casting according to a first embodiment of the present invention. In the roll of this embodiment, the roll shaft member 5 is fitted into the outer layer member 1, and the outer surface 7 of the crest 6 formed by the groove formed on the outer peripheral surface of the shaft member 5 (i.e., the shaft member trunk The entire outer circumferential surface) and the inner circumferential surface 2 of the outer layer member are diffusion bonded by hot isostatic pressing.

For the outer layer member 1, a wear-resistant material such as Cr-Mo-based low carbon alloy steel (for example, 1% Cr-0, 3% MoWfJ) can be appropriately selected and used. Usually, those that are cast by centrifugal force casting and then machined are used. On the other hand, the shaft member 5 can be appropriately selected from tough materials such as carbon steel for mechanical structures and alloy steel for structural uses, and machined.

The outer peripheral surface of the shaft member 5 is recessed with a spiral cooling medium feeding groove 3, and the opening of the groove 3 is closed by the inner peripheral surface 2 of the outer layer member l so that the cooling medium can be fed. Feeding channel 4
is formed. Coolant supply and discharge holes 9 and 1° (hereinafter referred to as "supply and discharge holes") are bored at both ends of the shaft member 5 along the axial direction.

The flow passages 4 communicate with supply and discharge holes 9.1° at the end of the body of the roll.

According to the roll according to the first embodiment, the cooling medium flows through the cooling medium supply hole 9.1 in the roll shaft, as indicated by the arrow in the figure.
The roll outer layer member 1 is fed from one end side of 0, for example 9.
The cooling medium is guided to the cooling medium feeding channel 4 on the inner circumferential surface 2 of the cooling medium. Then, after uniformly cooling the outer layer member by circulating the inner circumferential surface of the outer layer member in a spiral shape along the flow path 4, the supply/discharge hole 1 at the other end side is cooled.
It reaches 0 and is discharged.

In this way, all the peaks 6 on the outer circumference of the body of the roll shaft member 5
The outer surface (i.e., the outer circumferential surface of the shaft member body) 7 and the inner circumferential surface of the outer layer member 1 are solid-phase bonded (diffusion bonding) by hot isostatic pressure treatment.
Since the shaft member 5 and the outer layer member 1 are integrated, the force applied to the roll can be borne by the outer layer member 1 and the shaft member 5.

Further, since the cooling medium uniformly flows through the inner circumferential surface 2 of the roll outer layer member 1, an excessive temperature rise in the roll outer layer member 1 is prevented, and the temperature gradient between the body end portion and the center portion can be reduced.

FIG. 2 shows the structure of a prefabricated roll for continuous slab casting according to a second embodiment of the present invention. Arrows in the figure indicate the direction in which the cooling medium flows. Further, FIG. 3 schematically shows the path through which the cooling medium flows in the roll of FIG. 2, and the solid line in the figure represents the path through which the cooling medium flows, and the arrow indicates the direction in which it flows.

Similarly to the first embodiment, the roll of this embodiment also has an outer layer member 3.
The shaft member 32 is fitted onto the shaft member 1, and the outer circumferential surface of the body of the shaft member 32 and the inner circumferential surface of the outer layer member 31 are diffusion bonded by hot isostatic pressing.

A single spiral groove is formed in the outer peripheral surface of the body of the shaft member 32 from one end of the body to the other end.

The groove is divided into left and right parts by a closed part (indicated by a dotted line in FIG. 4) provided at the center of the body, and is used for feeding a first cooling medium from the center of the body toward one end of the body. A groove 33 (hereinafter referred to as "first groove j"), and a second cooling medium feeding groove 34 (hereinafter referred to as "second groove") facing the other end of the body without communicating with the first groove 33. ) are formed.

The openings of the first and second grooves 33, 34 on the outer peripheral surface of the body are closed by the inner peripheral surface 30 of the outer layer member 31,
A first cooling medium feeding channel 35 (hereinafter referred to as the "first channel") and a second cooling medium feeding channel 36 (hereinafter referred to as the "second channel") are formed. .

At both ends of the shaft member 32, there are first and second cooling medium supply and discharge holes 41 extending from the shaft end toward the center along the axial direction.
, 42 are drilled. One end of the supply/discharge holes 41, 42 is closed at the center of the body, and a small diameter hole 41a on the closed end side is closed.
, 42a and large diameter holes 41b, 42b on the shaft end side are formed concentrically and consecutively between the end of the body and the center. First and second introduction pipes 43 , 44 are arranged concentrically on the axial end sides of the re-supply/discharge holes 41 , 42 , respectively. .42 small diameter holes 41a, 42a and large diameter holes 41b, 42b are connected to each other, and are fixed to the inner peripheral surface of each supply/discharge hole, and are connected to the introduction pipe 43.
44 and the small diameter holes 41a and 42a, respectively, to form first and second introduction passages 37 and 38.

Further, first and second discharge passages 39 and 40 are respectively formed between the outer peripheral surfaces of the first and second introduction pipes 43 and 44 and the large diameter holes 41b and 42b of the supply and discharge holes.

Reference numerals 45 and 46 denote rotary joints, which are rotatably provided at both ends of the shaft member 32, and which are connected to the first and second introduction passages 37°3.
8, and communicate with the first and second discharge passages 39 and 40, respectively.

In this embodiment, the closed portion of the helical groove was set to cover half a revolution of the spiral, but the shorter the closed portion is, the better for uniform cooling of the roll surface. Therefore, it is desirable to shorten the closed portions and provide them close to each other, as indicated by the dotted arrows in FIG. 3, for example.

According to the roll according to this embodiment, the cooling medium flows through the first and second introduction paths 37 and 38 provided at both ends of the roll shaft member 32, as indicated by arrows in FIGS. 2 and 3. The first and second channels 35.3 of the inner circumferential surface 30 of the roll outer layer member 31 are fed from the center of the body of the shaft member 32.
6 respectively. Then, along the flow paths 35 and 36, the flow path 35 extends from the center of the body toward both ends of the body.
．． 36, from the center of the body toward both ends of the body, the outer layer member is cooled uniformly by going around the inner circumferential surface of the outer layer member in a spiral shape, and then the first and second discharge passages 39 at the ends of the body are cooled, respectively.
．． It reaches 40 and is discharged.

In this way, in this example, the cooling medium with no temperature rise is
It is supplied to the flow path in the center of the body and flows through the inner circumferential surface 30 of the roll outer layer member 31 from the center of the body toward the ends of each body, so that the center of the body, which is easily heated by the high-temperature slab, is particularly cooled. As a result, the temperature distribution on the surface of the roll body during continuous casting can be made more uniform than in the first embodiment.

In the above embodiment, the cooling medium is supplied from two introduction channels provided in the shaft portion to two non-communicating channels provided in the inner circumferential surface of the outer layer member. As shown in FIG. 4, a structure may be adopted in which the cooling medium is fed from one introduction path to the middle part of one spiral flow path that reaches from one end of the body to the other end of the body. . Alternatively, a structure may be adopted in which the cooling medium is fed from one introduction path to two channels that are not in communication with each other. However, Figures 2 and 3
With the structure shown in the figure, even if the flow rate of the cooling medium sent to each channel is uneven due to the difference in flow path resistance of the first and second cooling medium feeding channels, , the flow rate can be adjusted very easily.

Therefore, in continuous slab casting work, when the slab is not actually in contact with the slab, the temperature distribution from the center of the body to the left and right ends of the body can be easily controlled to be symmetrical with a low temperature peak in the center. . This makes it possible to easily equalize the temperature distribution on the surface of the body even if heating occurs at the center of the body due to the high-temperature slab during continuous slab casting work. Furthermore, even if the temperature distribution on the roll body surface changes during continuous slab casting, it is possible to uniformly control the temperature distribution on the roll body surface by adjusting the flow rate of the cooling medium flowing through each channel. It's easy.

FIG. 5 also shows that in the second embodiment described above, the pitch of the cooling medium feeding grooves formed on the outer circumferential surface of the body of the roll shaft member 32 is small in the central region of the body, which is in direct contact with the high-temperature slab. This shows a case in which the body end area is made larger in the region where it does not come into direct contact with the slab. The same parts as in FIG. 2 are indicated by the same numbers.

In the figure, since the central region of the outer layer member 31 that is heated by contact with the high-temperature slab can be intensively cooled, excessive temperature rise in this region can be further suppressed. Therefore, the temperature distribution on the outer circumferential surface of the outer layer member 31 can be kept more uniform during the continuous casting operation, so that the expansion of the central portion of the outer layer member 31 in the radial outward direction is suppressed.

The groove may be formed by forming a small pitch groove in the center region of the body and communicating with a large pitch groove formed in the end region of the body, as shown in FIG. Grooves may be formed with a pitch that gradually increases toward the end of the body.

As described above, the shaft member 32 and the outer layer member 31 are solid phase bonded (diffusion bonded) and integrated by hot isostatic pressure treatment, and the temperature distribution of the outer layer member 31 is uniform by supplying the cooling medium. Since the expansion of the outer layer member 31 in the radial direction is extremely small, the restraining force due to the thermal expansion of the outer layer member can be made uniform along the axial direction.

Next, specific manufacturing examples will be described.

Pinch roll for continuous continuous casting of wide slabs (450mmφ x 15
00 mmf) was manufactured with the structure of the first and second embodiments.

(2) Production of outer layer member A hollow cylindrical body was formed using a mold centrifugal casting method, and an outer layer member having an outer diameter of 450 mm, an inner diameter of 340 mm, and a length of 1500 nvnj2 was obtained by machining. The chemical composition (weight %) of the outer layer member is shown in Table 1 below.

Table 1 Note that since both of them will later be raised to a high temperature range by hot isostatic pressure treatment, only the casting stress was removed at 600'C after casting.

■ Manufacturing of shaft members On the outer circumferential surface of the shaft member made of carbon steel for machine structural use,
The following cooling medium feeding grooves were formed.

■-a 1st example Groove depth 15mm, groove width 20mm, pitch 70mm
Coolant supply and discharge holes are drilled along the axial direction at both wheel ends,
It communicated with the groove at the end of the body.

■-b Second Example Groove depth: 15 mm, groove width: 20 mm, pitch: 50111ff+ near the center, 100 near the body end Two grooves were formed from the center to the left and right ends of the body.

Furthermore, cooling medium supply holes were bored at both shaft ends, and first and second introduction pipes were provided to communicate with the grooves.

(2) Assembly The shaft member obtained in (1) and (2) above and the outer layer member were fitted together, the whole was sealed, deaerated, and placed in a hot isostatic presser to join and integrate the two.

The hot isostatic pressure treatment conditions are as follows.

Temperature Atmospheric pressure 1st example 1050'C1000 atm 2nd example
After hot isostatic pressing at 1100°C and 1000 atm, both rolls were subjected to strain relief heat treatment (550°CX201+) and final machining.

(2) When each of the rolls obtained above was subjected to actual continuous slab casting work, good results were obtained as shown in Table 2 below.

In addition, as a comparison roll, a through hole was formed in the center of the roll.
A roll having a structure in which a cooling medium is supplied to the through-holes for cooling (the roll body diameter and body length are the same as in the example) was manufactured and compared.

Table 2 (Effects of the Invention) According to the assembled roll for continuous slab casting of the present invention, the outer surface of the peak formed between the grooves formed on the outer peripheral surface of the body of the roll shaft member is Since the inner circumferential surface is solid phase bonded (diffusion bonded) and integrated by hot isostatic pressure treatment, no gap is formed between the outer surface of the peak and the inner circumferential surface of the outer layer member, Cooling water can always flow uniformly. In addition, since the force applied to the roll can be borne by both the outer layer member and the shaft member, stress concentration does not occur in the axial center of the outer layer member due to the force applied to the roll.
1. A crank may occur. Even if it occurs, it will not progress quickly.

In addition, two cooling medium feeding channels are formed from the center of the body toward the left and right ends of the body, and each flow path is provided in the shaft member at the center of the body. connected to the road. Therefore, since the cooling medium can flow from the center of the body into each flow path, it is possible to supply the cooling medium without a temperature rise to the center of the body, which is heated by the high-temperature slab. The roll surface can be uniformly cooled by suppressing the temperature rise in the roll.

Furthermore, by forming the pitch of the cooling medium feeding grooves small in the center of the body, which is in direct contact with the high-temperature slab, the center of the body can be cooled intensively, further reducing the temperature rise in the turning section. The roll surface can be cooled more uniformly.

Therefore, thermal expansion in the radially outward direction at the axial center of the outer layer member is suppressed, so that large forces are not applied not only to the ends of the outer layer member but also to the joint between the outer layer member and the roll shaft member. (Damage accidents in the outer layer members are less likely to occur.)

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an assembled roll for continuous slab casting according to the first embodiment of the present invention, FIG. 2 is a longitudinal sectional view of the same roll according to the second embodiment, and FIG. An explanatory diagram showing the path through which the cooling medium flows. FIG. 4 is an explanatory diagram showing the path through which the cooling medium flows in other rolls according to the second embodiment. FIG. Fig. 6 is a longitudinal sectional view of a conventional assembled roll for continuous slab casting, and Fig. 7 is an enlarged longitudinal sectional view of the main part of Fig. 6. It is a diagram. 1.31...Outer layer member, 2,30...Inner peripheral surface of outer layer member, 3...Cooling medium feeding groove, 4...Cooling medium feeding channel, 532... Shaft member , 33... first cooling medium feeding groove, 34... second cooling medium feeding groove, 37...
- First coolant introduction path, 38... second coolant introduction path, second discharge path. 39...first discharge path, 40...patent applicant Kubota Iron Works Co., Ltd.

Claims (3)

[Claims] (1) Cylindrical outer layer member (1) made of wear-resistant material,
Shaft members (5) and (32) made of a strong material and having cooling medium feeding grooves (3), (33), and (34) recessed in the outer peripheral surface of the body are fitted into (31). The openings of the grooves (3), (33), and (34) on the outer circumferential surface of the body are closed by the inner circumferential surfaces (2) and (30) of the outer layer member for supplying the cooling medium. An assembly type roll for continuous slab casting, characterized in that flow paths (4), (35), and (36) are formed. (2) The cooling medium feeding groove on the outer peripheral surface of the body of the roll shaft member (32) is a first cooling medium feeding groove (33) in a spiral shape extending from the center of the body toward one end of the body; A second spiral cooling medium feeding groove (34) extending from the center of the body to the other end of the body.
The first and second cooling medium feeding grooves (3
4) communicate with the cooling medium introduction passages (37) and (38) provided in the shaft member (32) at the center of the body, while the first and The assembled roll for continuous slab casting according to claim 1, characterized in that the rolls are in communication with the second discharge passages (39) and (40), respectively. (3) The pitch in the axial direction of the cooling medium feeding grooves (33) and (34) on the outer peripheral surface of the body of the roll shaft member (32) is formed to be small in the center region of the body and large in the end region of the body. The assembly type roll for continuous slab casting according to claim (2).