JP2647766B2 - 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 by weight of C: 2.0 to 3.2%, Si: 0.5 to 1.5%, M
n: 0.5 to 1.5% Ni: 0.8 to 2.5%, Cr: 10 to 25%, M
o: An inner layer made of a tough iron-based material is joined to the inner peripheral surface of an outer layer made of a high-compression-strength cast iron material consisting of 0.5 to 3.0% and the balance substantially consisting of Fe.

[0007]

The outer layer material of the strip winding spool of the present invention is as follows.
Thick-wall casting is possible, and iron chromium carbide with very high compressive yield stress has a structure of 15-40% by area crystallized in the steel matrix.Microscopically, high compressive yield stress due to carbide and due to matrix It is a composite material that combines toughness.

For this reason, the compressive strength is remarkably improved, and 120 kg
High compression strength of f / mm ² or more, less plastic deformation than conventional ductile cast iron and cast steel, and 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 iron chromium carbide with very high compressive yield stress in the steel matrix. The unit of the component is% by weight. C: 2.0 to 3.2% C mainly binds to Fe and Cr and also binds to Mo.
_It is added to form a composite carbide having a high compressive strength of ₇ C ₃ type. In order to secure the amount of composite carbide having high compressive strength, C of 2.0% or more is required. On the other hand, if the content of C exceeds 3.2%, 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: 0.5-1.5% Since Si is a cast alloy as the outer layer material, it is necessary to ensure the flowability of the molten metal. Also, it is used for deoxidation of the molten metal and eliminates pinholes during casting to reduce the required mechanical strength. It is an element necessary for securing. If the content of Si is less than 0.5%, the above effect cannot be expected. On the other hand, if the content of Si exceeds 1.5%, the mechanical properties (particularly, toughness) deteriorate, which is not preferable. Mn: 0.5-1.5% 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.
If the Mn% is less than 0.5%, the above effect cannot be expected.
If it exceeds 1.5%, the toughness is undesirably reduced. Ni: 0.8 to 2.5% Ni is an element that forms a solid solution in the matrix and improves the hardenability. If the Ni% is less than 0.8%, the effect is too small. On the other hand, if the Ni% exceeds 2.5%, the effect is saturated.
%. Cr: 10 to 25% Cr combines with C together with Fe and Mo to form a composite carbide having a high compressive strength, supports 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 the Cr content is less than 10%, the above effect cannot be expected.
%, It is not preferable because toughness is reduced. Mo: 0.5 to 3.0% Mo enhances the quenching and tempering resistance and at the same time 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 the Mo% is less than 0.5%, the above effects cannot be expected, and if the Mo% exceeds 3.0%, the toughness is lowered, which is not preferable. The outer layer material according to the present invention, in addition to the above components,
And formed by impurities inevitably mixed. Note that P
Since S and S degrade the toughness, it is desirable that the contents be as small as possible. The inner layer bonded to the inner peripheral surface of the outer layer is high-grade cast iron (high-strength flaky graphite cast iron)
, Ductile iron, adamite material (high carbon cast steel), graphite steel, high chromium cast steel and other iron-based tough materials. 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 to 2.3%, Si: 0.5 to 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 For compounding of the outer layer and the inner layer, the outer layer is cast by centrifugal casting, and then the inner layer material is continuously melted on the inner peripheral surface of the outer layer. There is a method of pouring, welding and integrating the outer layer and the inner layer,
Since it is simple, it is generally applied. In order to prevent Cr from mixing from the outer layer to the inner layer when the outer layer and the inner layer are welded, it is preferable to form an intermediate layer on the inner surface of the outer layer by welding and then weld the inner layer to the inner surface. As the intermediate layer material, the above-mentioned adamite material is suitable.

[0010] 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 a heat treatment for reducing residual stress and transforming retained austenite into a thermally stable layer. Are roughly classified into this heat treatment, repeated several times at a relatively high temperature tempering below ₃ points A, a method of thermally stable pearlite decomposes retained austenite and (strain relief annealing), A _3-point temperature higher than Then, after heating again to the austenite region and precipitating supersaturated C and Cr as secondary carbides,
A method in which the matrix is made into a mixed phase of secondary carbide and pearlite or tempered martensite and pearlite by quenching and tempering heat treatment with controlled cooling rate by spray water cooling or forced air cooling (austenite instability and quenching / tempering). . By such heat treatment, the base structure can be selected from pearlite to tempered martensite.

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 1 (A) was cast into a cylindrical mold rotating on a centrifugal casting machine. The casting amount is the casting thickness 1
09mm. (2) After casting the outer layer, the molten adamite material described in Table 1 (A) was cast on the inner surface to form an inner layer. Cast material: black scale outer diameter φ 812 mm, black scale outer layer thickness 86 mm, black scale inner diameter φ 560 mm
Met. The composition of the inner layer after welding is shown in Table 1 (B).

[0013]

[Table 1]

(3) For Example 1, 10 hours at 550 ° C.
After performing the strain relief annealing, rough processing is performed, and austenite is destabilized at 1000 ° C and quenched at 400 ° C / hr, 500 ° C
For tempering. After that, finishing was performed to obtain a product spool. (4) Table 2 shows the mechanical properties of each layer after the heat treatment.

[0015]

[Table 2]

According to Table 2, not only in Example 1 in which quenching and tempering heat treatment was performed, but also in Example 2 in which only strain relief annealing was performed, the compression strength of the outer layer was as large as 137 kgf / mm ^2, and the conventional cast steel was 90 kgf / mm ^2. Although it was about ² mm ² or less, a remarkable improvement in compressive strength was 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.

[0017]

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. Further, since the plastic change hardly occurs, the inner and outer surfaces of the spool do not need to be re-grinded even when the spool is used frequently, and the maintenance-free spool is obtained.

Claims (1)

(57) [Claims] C. 2.0 to 3.2%, Si: 0.5 to 1.5%, M
n: 0.5 to 1.5% Ni: 0.8 to 2.5%, Cr: 10 to 25%, M
o: Strip winding characterized in that an inner layer made of a tough iron-based material is joined to an inner peripheral surface of an outer layer made of a high-compression-strength cast iron material consisting of 0.5 to 3.0% and the balance substantially made of Fe. spool.