JPS62280305A - Production of roll - Google Patents

Abstract

PURPOSE:To easily obtain a roll having high reliability at the time of rolling by disposing shaft materials to both ends of a metallic capsule, packing metallic powder between the shaft materials, subjecting the powder to a hot hydrostatic press treatment in a high-temp. high-pressure gaseous atmosphere and sintering the powder molding. CONSTITUTION:The shaft material 2 made of a low-alloy steel, etc., is mounted to one side of the capsule 1 and after the metallic powder 3 is packed thereon, the other shaft material 2' is mounted to the capsule. Cap bodies are then fixed to the capsule 1 and the inside thereof is deaerated and hermetically sealed. Such capsule assembly 3 is loaded into an HIP furnace and is subjected to the hot hydrostatic press treatment in the high-temp. high-pressure gaseous atmosphere to metallurgically join and unite the metallic powder body 3 and the shaft materials 2, 2'. The capsule 1 is removed by suitable means and the resultant roll base material is worked to a prescribed roll shape. This method is suitable for production of a small-diameter roll having a large barrel length.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for manufacturing a roll using a hot isostatic pressing method (hereinafter referred to as the HIP method).

(Prior Art) Conventionally, rolling rolls have been produced in one piece by casting or forging, and the desired properties are imparted through necessary heat treatment. A method of producing a composite roll in which a powder sintered layer is formed has been attracting attention, and is known, for example, as disclosed in Japanese Patent Application Laid-Open No. 47-2851 and Japanese Patent Application Laid-Open No. 56-69304.

The former manufacturing method involves covering the entire roll with a metal capsule, filling the portion that will become the roll surface layer with a predetermined metal powder, and loading the entire roll into a HIP furnace to perform HIP treatment. In the latter case, a metal capsule is attached to the outer periphery of a solid roll core material so as to form an annular space that becomes a metal powder filling layer, and after filling the annular space with metal powder and sealing it, it is charged into a HIP furnace. The powder is densely sintered by HIP treatment, and then the capsules are removed and roll supports are metallurgically or mechanically joined to both ends of the solid roll core material to produce a roll. It is something.

(Problem to be solved by the invention) However, in the former manufacturing method, the entire roll is charged into the HIP furnace, so for large rolls, the important HIP processing section that occupies a correspondingly large space inside the HIP furnace is the roll. Since it only covers the surface layer of the main body, the HIP processing efficiency is extremely poor.
The energy cost and atmospheric gas cost per unit weight of the required HIP processing section are extremely high, making it impractical. Therefore, the rolls that can be manufactured by this method are limited to extremely small rolls. On the other hand, the latter manufacturing method involves dividing the roll into a main body part that requires HIP processing and a roll support part that does not require HIP processing, and then HIPing only the roll main part, and then integrating the two parts by welding. , which solves the former drawback and has a certain effect as HIP processing efficiency is increased. However, even in this latter manufacturing method, the length of the roll that can be manufactured is limited by the dimensions of the H[P equipment. That is, HI
It is not possible to manufacture rolls with a body length larger than the P equipment.

Further, in a roll having a composite structure, residual stress is generated at the boundary between the outer shell layer and the shaft core material during quenching, reducing the reliability of the boundary when subjected to rolling.

Furthermore, the roll support part (roll shaft) is joined using a method other than metallurgy, in particular electroslag or electrogason welding, and the joining time is determined by polishing, quenching, or tempering the surface of the sintered layer. After processing and heat treatment. Since the above welding method involves high heat input welding, the weld metal becomes coarse grained, so it must be subjected to normalizing and tempering heat treatment or post-welding heat treatment for refining, so the roll body is quenched and tempered. After that, the treatment becomes localized, generates large residual stress, and reduces reliability during rolling.

(Means for Solving the Problems) In view of the above-mentioned points, the present invention aims to provide a method for manufacturing rolls with high reliability during rolling at low cost, and further provides rolls with a body length larger than that of HIP equipment. The purpose is to provide a method for easily manufacturing a metal capsule, and as a means to achieve this purpose, forged or cast shaft members made of low-alloy steel, etc. are placed at both ends of the metal capsule, and there is a substantial distance between the shaft members. The powder body and the shaft material are metallurgically bonded together by filling a metal powder body made of metal powder and subjecting them to hot isostatic pressing in a high-temperature, high-pressure gas atmosphere to densely sinter the powder body. A configuration is adopted in which a rolled base material is obtained, and then the roll base material is formed into a predetermined roll shape by a processing means, and further, as the processing means,
This method employs the various means described in Sections 9 to 9.

(Example) Hereinafter, an example of the method of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows HIP for creating the roll base material 5 of the present invention.
This figure shows a cross-sectional view of the assembly 4 after the preparation process for processing has been completed, where l is a cylindrical metal capsule consisting of a bottom, a body, and a lid, and one side of the capsule 1 (bottom in the illustration)
After inserting or attaching the shaft material 2 that will become the roll support part and positioning it, and filling it with the metal powder 3, the other shaft material 2' that will become the roll support part is placed on top of the metal powder body 3. After insertion or attachment, and then fixing the lid, the inside of the capsule 1 is degassed and sealed. The outer diameter of the shaft members 2, 2' is the same as the inner diameter of the capsule 1, and the wall thickness thereof is designed by calculation so as to have a sufficient volume to later serve as a roll support portion. The material is the roll support part (such as low alloy steel).
It is preferable to use a material that satisfies the required characteristics as a roll shaft (roll shaft).As will be described later, in the case of an embodiment in which an extended shaft member is further welded, a material that can be welded is required. On the other hand, the metal powder 3 may be used only as a metal powder or as a powder sintered material 3 having approximately the same composition as the metal powder. High C High Cr
It is preferable to use a material that satisfies the characteristics required for the roll body, such as tool steel or high-speed steel. In addition, it is preferable from a cost standpoint that the latter powder sintered material uses a powdered sintered roll material of the same material, which has a reduced diameter for disposal, as the core material.

The inside of the capsule 1 is degassed through a degassing pipe 1' provided in the body, but the capsule 1 may be sealed without being degassed.

Capsule assembly 4 with the preparation process completed as described above
Next, it is charged into a HIP furnace and heated under a high temperature and high pressure gas atmosphere, preferably 9 (10~1, 2 (10℃), 7 (10kg/
By performing HIP treatment (hot isostatic pressure treatment) under conditions of ct1 or more, the metal powder body 3 and the shaft members 2, 2' disposed on both sides thereof are metallurgically joined and integrated. A roll base material 5 is obtained.

This roll base material 5 is as shown in FIG. 2, which shows a state in which the capsules 1 have been removed by appropriate means.

In other words, the metal powder body 3 portion becomes a dense powder sintered body 3a, and its outer diameter becomes smaller and its length is also reduced.
No deformation is observed in the shaft members 2, 2', and the boundaries 6, 6 between the shaft members 2, 2' and the powder sintered body 3a are metallurgically firmly joined and integrated.

In the present invention, the roll base material 5 obtained as described above is formed into a predetermined roll shape by the processing means shown in the embodiments below.

The processing means shown in FIGS. 3 and 4 is for forging the roll base material 5 into a predetermined shape and then refining the outer shape.

That is, the roll base material 5 is formed into a roll shape by forging and stretching, and 7 represents a roll body and 8.8' represents a roll support portion. For convenience, the trunk 7 refers to the A section shown in the figure, and the roll support section 8.8'' refers to the B section, but this is not meant in a strict sense (in Fig. 3, the boundary 6.6 is It is located on the roll support part 8.8'' side, and FIG. 4 shows the boundary 6.6 located on the roll body 7 side.

FIG. 5 shows processing means for cutting a roll base material into a predetermined shape and then refining the outer shape. In this case, the shaft members 2, 2'' arranged and integrated at both ends of the roll base material 5 are thick enough to form the roll support parts 8, 8'' and have a length in the axial direction)
The shape after cutting is shown by the dotted line in the figure.

Figure 6 shows a roll as a processing means, and extended shaft members 9 at both ends of the base material 5 with a diameter smaller than that of the roll support made of low alloy steel, etc.
, 9' are joined by welding 10, 10', and after cutting the whole into a predetermined shape as shown by the dotted line, the outer shape is refined. Therefore, according to this method, the roll support parts 8, 8' are formed by the shaft members 2, 9, 2', 9'.

Fig. 7 shows that as a processing means, an extension shaft member 9.9' having the same diameter as the shaft members 2, 2' made of low alloy steel etc. is joined to both ends of the roll base material 5 by welding 10.10'. A) Then, as shown in FIG. 7B, the whole is drawn and forged into a predetermined shape, and then the outer shape is refined.

Fig. 8 shows a processing method in which a roll base material 5 is forged to predetermined conditions, and extended shaft members 9,9゛ made of low-alloy steel or the like having the same diameter as the forged shaft members 2,2° are welded to both ends of the roll base material 5. They are joined by 10° and 10°, and then the external shape is refined. Note that this method is the same as that of FIGS. 3 and 4 by welding extension shaft members 9 and 9 to both ends of the roll support portions 8 and 8 degrees.

FIG. 9 shows a processing method in which a roll base material 5 is cut into a predetermined shape, and extension shaft members 9.9'' made of low alloy steel or the like are welded to both ends of the roll base material 5, and the outer shape is then refined.

FIG. 10 shows a processing method in which a roll base material 5 is forged into a predetermined shape, that is, the same as in FIGS. 9″
are joined by cast joints 11 and 11', and the external shape is then refined.

FIG. 11 shows a process in which a roll base material 5 is cut into a predetermined shape, that is, the same shape as shown in FIG. 11.11', and then the external shape is refined.

As described above, in each of the embodiments of the present invention shown in FIGS. 3 to 11, the roll support portion is It goes without saying that the rolls 8, 8' or the body 7 may be appropriately subjected to thermal refining, quenching, and tempering to impart the properties required for the roll.

Although the forging means is not explained in detail in the examples, a well-known hot or cold forging method is used.

More specific examples of the method of the present invention will be described below.

(Example 1) A disc-shaped shaft material of 450φ x 50t (i+*) was inserted into a cylindrical metal capsule with internal dimensions of 450φ x 1,20OA (n), and C: 2%, Cr: 1B% ,
Fill tool steel powder (metal powder) with gate 0: 2%, ■ = 1% and the balance iron, and fill the powder with 450
A disc-shaped shaft member of φ x 50t (mu) was inserted and set, the upper cover was welded, and the assembly was constructed by vacuum degassing, and then HIP treatment was performed in a high-temperature, high-pressure gas atmosphere. The inserted shaft material was degreased after being machined.

Through this process, the metal powder is densely sintered, and the roll base material is metallurgically integrated with both shaft materials at the boundary, which is then forged and stretched until the body has a diameter of 340φU. After that, the shaft material is thermally treated, and the quenched and tempered extension shaft material is further welded to both ends of the shaft material to integrate it, resulting in a body diameter of 340φ and a body length of 1.5 (10 mm). We were able to produce roll material with a total length of 3.7 (10j2 (dragon)).

Furthermore, this roll material is subjected to induction hardening, tempering, and refining to create a body diameter of 320φ and body length of 1,420mm with high hardness and excellent wear resistance, accident resistance, and roughness resistance! ,
A work roll with a total length of 3.5 (10β (1 yen)) was manufactured.

(Example 2) A shaft material made of low-alloy copper of 450φ×2 (10β) was inserted into a cylindrical metal capsule with internal dimensions of 450φ×1.5 (10E (m weight), and on top of the shaft material Tool steel powder having the same composition as 1 and a core material made of powder sintered material having the same composition (see number 3 in Fig. 1) are filled, and on top of the powder and sintered material, the same as above is filled. 450φX 2 (10
& (u+) shaft material was inserted, the upper cover was welded, and vacuum degassed to form an assembly, which was then subjected to HIP treatment in a high temperature and high pressure gas atmosphere.

Note that the insertion shaft material and the powder sintered material were degreased after being machined.

Through this treatment, the powder body and the powder sintered material are completely metallurgically integrated and densely sintered, and the roll base material is metallurgically integrated with both shaft materials at the boundary thereof.
By forging this, the body has a diameter of 320mm and the shaft has a diameter of 220mm.
After forging and forming the shaft material to
(We were able to produce 10 J roll material.

Furthermore, this roll material is subjected to induction hardening, tempering treatment, and refining treatment to create a body diameter of 3 (10φ, body length 1) with high hardness and excellent wear resistance, accident resistance, and roughness resistance. ,4
A 2ON work roll with a total length of 2.80 (H!) was manufactured.

(Effects of the Invention) The present invention obtains a roll base material consisting of a body made of metal powder densely sintered by HIP means and a shaft material metallurgically bonded to both sides of the body. Since it is formed into a predetermined roll shape by appropriate processing means, rolls with high reliability during rolling can be manufactured at low cost.

In particular, in the present invention, since the body is formed only from sintered powder, forging, which was difficult with the conventional composite roll having a composite boundary as exemplified at the beginning, is easy.
Since it is not subject to the dimensional restrictions of P equipment, it is suitable for manufacturing rolls with a small diameter and a long body.

In addition, after the roll body member made of metal powder, which is difficult to weld (or has a refractory layer), and the shaft material, which can be welded (fused), are metallurgically joined and integrated by HIP processing, this shaft material is further bonded. Since the extended shaft members can be joined by welding (cast joint), etc., large rolls can be manufactured using small HIP equipment.

In addition, since there is no composite boundary like in conventional composite rolls, there are fewer restrictions on the depth at which the shell is heated above the AC transformation point during quenching, making operations easier and improving the quality inside the shell. do.

[Brief explanation of the drawing]

The drawings show an embodiment of the method of the present invention; FIG. 1 is a sectional view of an assembly after completing the preparation process for HIP treatment to create the roll base material of the present invention, and FIG. 2 is a cross-sectional view of the book obtained after HTP treatment. The side sectional views of the roll base material of the invention, FIGS. 3 to 11, also serve as explanatory diagrams when the roll base material is processed by various processing means, and each shows a side sectional view of the roll obtained thereby. It is. ■...Metal capsule, 2,2°...Shaft material, 3...
Metal powder body, 4... Assembly, 5... Roll base material, 7
...Body part, 8゜8" ...Roll support part, 9,9"
・・Extended shaft material, 10.10″・・Welded part, 11.1
1”...cast joint part. ・!: 1i

Claims (10)

[Claims] (1) A forged or cast shaft made of low-alloy steel or the like is placed at both ends of a metal capsule, and a metal powder made of substantially metal powder is filled between the shafts, and they are placed in a high-temperature, high-pressure gas atmosphere. The powder is densely sintered by hot isostatic pressing to obtain a roll base material in which the powder and the shaft material are metallurgically bonded and integrated, and then the roll base material is processed by processing means. A method for manufacturing a roll, the method comprising forming the roll into a predetermined roll shape. (2) Claim 1, characterized in that the processing means involves forging the roll base material into a predetermined shape and then refining the outer shape.
2. Method for manufacturing the roll described in Section 1. (3) Claim 1, characterized in that the processing means involves cutting the roll base material into a predetermined shape and then refining the outer shape.
2. Method for manufacturing the roll described in Section 1. (4) As a processing means, extended shaft members made of low-alloy steel or the like are welded to both ends of the roll base material, and after cutting the whole into a predetermined shape, the outer shape is refined. A method for manufacturing a roll according to item 1. (5) As a processing means, extended shaft members made of low-alloy steel or the like are welded to both ends of the roll base material, the whole is forged into a predetermined shape, and the outer shape is refined. A method for manufacturing a roll according to item 1. (6) The scope of claims characterized in that the processing means is forging a roll base material into a predetermined shape, welding extension shaft members made of low alloy steel or the like to both ends thereof, and then refining the external shape. A method for manufacturing a roll according to item 1. (7) The scope of claims characterized in that the processing means involves cutting a roll base material into a predetermined shape, then welding extension shaft members made of low-alloy steel or the like to both ends thereof, and then refining the external shape. A method for manufacturing a roll according to item 1. (8) A patent claim characterized in that, as a processing means, after forging a roll base material into a predetermined shape, extension shaft members made of steel or cast iron are joined to both ends of the roll base material by a cast joint, and then the outer shape is refined. A method for manufacturing a roll according to item 1. (9) A patent claim characterized in that, as a processing means, after cutting a roll base material into a predetermined shape, extension shaft members made of steel or cast iron are joined to both ends of the roll base material by casting joints, and the outer shape is then refined. A method for manufacturing a roll according to item 1. (10) The metal powder body is made of a metal powder that can satisfy the characteristics required for the roll body of high C, high Cr tool steel, high speed steel, etc., and a powder sintered material having the same components as the powder. A method for manufacturing a roll according to one of claims 1 to 10, characterized in that: