JP2647767B2 - Strip take-up spool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spool used for winding a strip of aluminum, copper, stainless steel or the like.

[0002]

2. Description of the Related Art After thin rolling of stainless steel or the like, the strip is wound on a spool which is attached to a winding device and fixed detachably. The spool is cylindrical,
The winding torque is transmitted by inserting a mandrel with a reduced diameter through an uneven portion provided at the end or inside the spool, and expanding and fixing the mandrel. The spool on which the strip has been wound is removed together with the strip from the winding device and transported.

[0003] The spool has conventionally been manufactured by machining a pipe material cast from ductile cast iron or cast steel. Incidentally, cast steel, the compression yield strength but comprise up to about 90 kgf / mm ^2, is difficult thick casting, because of a problem in the health of the inner surface, which is exclusively applied to the spool of the thickness about 50mm or less thin .

[0004]

In recent years, winding conditions such as an increase in winding tension and a winding speed, a reduction in the thickness of a winding material (strip), and an increase in a winding amount have become severe. The tightening force is increased, and as a result, in the conventional spool, large elastic deformation and plastic deformation such that the diameter is reduced in an hourglass shape from both ends to the center of the spool are generated. For this reason, the product coil may be wrinkled,
There is also a problem that the mandrel cannot be removed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a strip winding spool which does not cause plastic deformation or large elastic deformation, does not cause winding wrinkles, and can be easily attached and detached with a mandrel. .

[0006]

The take-up spool of the present invention has a chemical composition in weight%, C: 1.5-2.5%, Si: 0.2-1.0%, M
n: 1.5 or less Ni: 2% or less, Cr: 3 to 10%, M
o: 1 to 9% W: 2 to 8%, V: 2 to 10%, and the balance of the outer layer formed of a high-compression-strength cast iron material substantially made of Fe has an inner layer made of an iron-based tough material on the inner peripheral surface. The junction is formed.

[0007]

The outer layer material of the strip winding spool of the present invention is as follows.
Thick wall casting is possible, and carbide with very high compressive yield stress has a structure of 8 to 30 area% crystallized in the steel matrix. Microscopically, high compressive yield stress by carbide and toughness by matrix This is a composite material that combines

For this reason, the compression proof stress is remarkably improved,
comprising a gf / mm ² or more high compressive yield strength, plastic deformation does not easily occur as compared with the conventional ductile iron and cast steel, also high Young's modulus
(E = 22000kgf / mm ² or more), and is less likely to be elastically deformed than conventional materials. In addition, since the inner layer made of iron-based tough material is joined to the inner peripheral surface of the outer layer, it is resistant to damage against shocks generated when attaching and detaching the mandrel and shocks caused during handling such as transportation, Excellent durability.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The spool of the present invention has a composite structure in which an inner layer formed of a ferrous tough material is joined to an inner peripheral surface of an outer layer formed of a cast iron material having a very high compressive yield stress. First,
The reasons for limiting the components of the cast iron material forming the outer layer will be described. Each component is defined below to produce the required amount of composite carbide with very high compressive yield stress in the steel matrix. The unit of the component is% by weight.

C: 1.5 to 2.5% C mainly combines with Fe, Cr and Mo to form a composite carbide having a high compressive strength of M ₇ C ₃ type,
Combined with r, Mo, V, W, it also forms MC type high compressive strength composite carbide. In order to secure this high compressive strength composite carbide content, 1.5% or more of C is required. On the other hand, if the content of C exceeds 2.5%, the amount of carbide increases and the material becomes brittle, which is unsuitable in terms of toughness, and at the same time causes cracking during casting. Si: 0.2 to 1.0% Since Si is a cast alloy as the outer layer material, it is necessary to secure the flowability of the molten metal. Also, it is used for deoxidation of the molten metal, eliminating pinholes at the time of casting to reduce the required mechanical strength. It is an element necessary for securing. If the Si% is less than 0.2%, the above effect cannot be expected. On the other hand, if the Si% exceeds 1.0%, the mechanical properties (particularly the toughness) deteriorate, which is not preferable.

Mn: 1.5% or less Mn acts as an aid for deoxidation in Si. Further, it is an element that combines with S to form MnS and prevents embrittlement due to S.
However, when the content exceeds 1.5%, the toughness is remarkably reduced, which is not preferable. Ni: 2% or less Ni cannot be expected to undergo secondary hardening during tempering, but addition of 2% or less is effective for improving hardenability.
If it exceeds 2%, austenite is stabilized and the retention of the matrix is not good.

Cr: 3 to 10% Cr combines with C together with Fe, Mo, V, and W to form a high compressive strength composite carbide to support the matrix, and has a high compressive strength as a whole structure. Some also form a solid solution in the matrix to improve the matrix and improve mechanical properties.
If Cr% is less than 3%, the above effects cannot be expected, while 10%
If the content exceeds 0.005%, the toughness is undesirably reduced. Mo: 1 to 9% Mo enhances the quenching and tempering resistance and simultaneously enters the carbide to increase the compressive strength of the carbide. Further, it is effective in improving the compression resistance of the matrix and promoting the tempering softening resistance. If Mo% is less than 1%, the above effects cannot be expected.
If it exceeds 9%, the above effects are saturated and the toughness is lowered, which is not preferable.

W: 2 to 8% W is a strong carbide-forming element and is composed of Fe, Cr, Mo, V
Together with C to form a composite carbide having a high compressive strength, supporting the matrix and having a high compressive strength. If it is less than 2%, the above effects cannot be obtained. On the other hand, if it exceeds 8%, the toughness decreases, which is not preferable. For this reason, it is set to 8% or less. V: 2 to 10% V easily bonds with C together with Fe, Cr, Mo, and W,
It mainly forms MC type high compressive strength composite carbides and has high compressive strength. In addition, since the MC-type composite carbide is granular, it contributes to the improvement of mechanical properties and crack resistance. If it is less than 2%, the above effect cannot be expected because the amount of carbide is too small. On the other hand, if it exceeds 10%, the toughness is reduced, which is not preferable. For this reason, it is set to 10% or less.

The outer layer material according to the present invention is formed of Fe and unavoidable impurities in addition to the above components. Since P and S degrade the toughness, it is desirable that they are small, and it is better to keep both of them at 0.05% or less. The inner layer joined to the inner peripheral surface of the outer layer is formed of an iron-based tough material such as high-grade cast iron (high-strength flake graphite cast iron), ductile cast iron, adamite material (high-carbon cast steel), graphite steel, and high-chromium cast steel. Examples of these preferred components are shown below.
The unit is% by weight, and the balance is substantially Fe. When the outer layer and the inner layer are welded, the erosion thickness setting is determined in consideration of the amount of components mixed in from the outer layer.

High-grade cast iron C: 2.5-4.0%, Si: 0.8-2.5%, M
n: 0.2 to 1.5% P: 0.2% or less, S: 0.2% or less, N
i: 0.5 to 3.0% Cr: 2.0% or less, Mo: 0.2% or less Ductile cast iron C: 2.5 to 4.0%, Si: 1.3 to 3.5%, M
n: 0.2 to 1.5% P: 0.2% or less, S: 0.2% or less, N
i: 0.5 to 3.0% Cr: 2.0% or less, Mo: 2.0% or less M
g: 0.02-0.1% Adamite material C: 1.0-2.5%, Si: 0.5-1.5%, M
n: 0.2 to 1.5% P: 0.2% or less, S: 0.2% or less, N
i: 1.5% or less Cr: 2.0% or less, Mo: 2.0% or less

Graphite steel C: 1.0-2.3%, Si: 0.5-3.0%, M
n: 0.2 to 1.5% P: 0.2% or less, S: 0.2% or less, N
i: 0.5 to 3.0% Cr: 2.0% or less, Mo: 2.0% or less High chrome cast steel C: 0.8 to 1.2%, Si: 0.3 to 1.0%, M
n: 0.3 to 1.0% P: 0.03% or less, S: 0.03% or less, N
i: 0.4 to 1.5% Cr: 11 to 12%, Mo: 2.0% or less

As for the compounding of the outer layer and the inner layer, a method of casting the outer layer by centrifugal force casting, subsequently pouring the inner layer material molten metal onto the inner peripheral surface of the outer layer, and welding and integrating the outer layer and the inner layer. It is generally applied because it is simple and convenient.
When the outer layer and the inner layer are welded, the Cr from the outer layer to the inner layer
In order to prevent the mixing of the intermediate layer, an intermediate layer is preferably formed by welding on the inner surface of the outer layer, and the inner layer is welded to the inner surface. As the intermediate layer material, the above-mentioned adamite material is suitable.

Alternatively, the outer layer material and the inner layer material may be separately manufactured, and after fitting, the two may be integrated by diffusion bonding by hot isostatic pressing. In the case of the welding method, the inner surface of the outer layer is partially melted, high alloy components are mixed in the inner layer molten metal, and the toughness of the inner layer is reduced. No problem. Further, low-alloy steels for machine structures such as carbon steel for machine structures, SCM materials, and SNCM materials can also be used.

The composite material in which the outer layer and the inner layer are joined is usually subjected to the following heat treatment. First, rough processing after stress relief annealing conducted, subjected to quenching treatment after heating maintained at a high temperature of more than _three points A, a low intensity austenite structure is transformed into fine and tough matrix structure (martensite or bainite). Further, secondary hardening due to precipitation of special carbide from the matrix structure and tempering treatment for decomposing residual austenite are performed. By performing the heat treatment, a predetermined compressive strength can be imparted to the outer layer.

Next, outer diameter φ 800 mm, inner diameter φ 600 mm, body length 13
A specific example of the 00 mm take-up spool will be described. (1) The molten outer layer material shown in Table 3 (A) was cast into a cylindrical mold rotating on a centrifugal casting machine. The casting amount is shown in Table 1 below in terms of casting thickness.

[0021]

[Table 1]

(2) After casting the outer layer, the molten adamite material described in Table 3 (A) was cast on the inner surface to form an inner layer. The dimensions of the casting material were as shown in Table 2 below. The composition of the inner layer after welding is shown in Table 1 (B).

[0023]

[Table 2]

[0024]

[Table 3]

(3) The casting material was subjected to the following heat treatment after roughing, and then to a finishing process to obtain a product spool. Example 1: After annealing for 10 hours at 580 ° C for 10 hours, at 1130 ° C
Hold for 2 hours, quench at 400 ° C / hr,
Tempering was performed at 550 ° C for 15 hours. Example 2: After annealing for 10 hours at 600 ° C for 10 hours, at 1150 ° C
Hold for 1 hour, quench at 400 ° C / hr,
Tempering was performed at 550 ° C for 20 hours. Example 3: After annealing for 10 hours at 580 ° C for 10 hours, at 1120 ° C
Hold for 3 hours, quench at 400 ° C / hr,
Tempering was performed at 550 ° C for 20 hours. (4) Table 4 shows the mechanical properties of each layer after the heat treatment.

[0026]

[Table 4]

From Table 4, the compressive strength of the outer layer of the embodiment is 203 kgf.
/ mm ² or more, whereas the conventional cast steel is about 90 kgf / mm ² or less, a remarkable improvement in compressive strength is observed. In addition, despite the fact that the outer layer was thick, there were no casting defects, and the welded state between the outer layer and the inner layer was good.

[0028]

As described above, in the strip take-up spool of the present invention, the outer layer is formed of a cast iron material having a specific composition, and the inner layer of the iron-based tough material is formed on the inner peripheral surface thereof, thereby achieving high compression. It is possible to form a thick outer layer of proof stress, it is difficult for elastic deformation and plastic deformation to occur due to the tightening force generated by winding the strip, and thus the occurrence of winding wrinkles is prevented, and the mandrel can be smoothly attached and detached. Further, by forming an inner layer, it is excellent in impact resistance and durability. Furthermore, since plastic deformation is unlikely to occur, there is no need to re-grind the inner and outer surfaces of the spool even when the spool is used frequently, and the maintenance-free spool is obtained.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akiyoshi Okabayashi 64, Nishimujimajima-cho, Amagasaki-shi, Hyogo Pref. In Kubota Amagasaki Plant Co., Ltd.

Claims (1)

(57) [Claims] C. 1.5 to 2.5%, Si: 0.2 to 1.0%, M
n: 1.5% or less Ni: 2% or less Cr: 3 to 10%, M
o: 1 to 9% V: 2 to 10%, W: 2 to 8%, and the balance of the outer layer formed of a high-compression-strength cast iron material substantially made of Fe has an inner layer made of an iron-based tough material on the inner peripheral surface. A strip take-up spool formed by joining.