JP2774745B2 - 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 that can be expanded and contracted into the spool via a concave and convex portion provided at the end thereof or in a reduced diameter state, 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: 0.9 to 1.5%, Si: 0.5 to 1.5%, Mn: 0.5 to 1.5% Ni: 2.0% or less, Cr: 9 to 20%, Mo: 0.3 to 3.0% V: 0.2 to 1.0% and the balance substantially consisting of Fe
Iron-based toughness is applied to the inner peripheral surface of the outer layer made of compression-resistant cast iron material.
An inner layer made of a material is formed by joining.

[0007]

The cast iron material of the outer layer of the strip take-up spool according to the present invention can be cast in a thick wall, and iron chromium carbide having a very high compression yield stress is contained in a steel matrix of 5 to 5 mm.
It is a composite material that has a structure crystallized at 15% by area and has both high compressive yield stress by carbide and toughness by matrix.

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. Therefore, by forming the outer layer with the high compression strength cast iron material and joining the inner layer made of the iron-based tough material to the inner peripheral surface thereof, the outer layer is formed in handling such as impact and conveyance generated when attaching and detaching the mandrel. It is possible to improve the resistance to breakage and durability against shocks and the like.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The outer layer of the strip take-up spool of the present invention is as follows.
It is formed of a cast iron material having a very high compressive yield stress, and each component is limited for producing the required amount of iron chromium carbide having a very high compressive yield stress in the steel matrix for the following reasons. The unit of the component is% by weight. C: 0.9 to 1.5% C mainly combines with Fe, Cr and Mo to form a composite carbide having high compressive strength of M ₇ C ₃ type. 0.9% or more of C is necessary to secure the amount of composite carbide having high compressive strength. On the other hand, if the content exceeds 1.5%, 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: 0.5-1.5% 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 Si is less than 0.5%, the above effects cannot be expected, while if it exceeds 1.5%, mechanical properties (particularly toughness)
This is not preferred because it causes deterioration of. Mn: 0.5-1.5% Mn acts as an aid for deoxidation by Si. Further, it is an element that combines with S to generate MnS and prevents embrittlement due to S. If Mn is less than 0.5%, the above effects cannot be expected.
If it exceeds 1.5%, the toughness is undesirably reduced. Ni: 2.0% or less Ni is an element that forms a solid solution in the matrix and improves the hardenability. If the content exceeds 2.0%, the effect is saturated, so the content is set to 2.0% or less. Cr: 9 to 20% Cr combines with C together with Fe and Mo to form a composite carbide having high compressive strength, supports the matrix, and has 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 content of Cr is less than 9%, the above effect cannot be expected. If the content exceeds 20%, the toughness is lowered, which is not preferable.
Mo: 0.3 to 3.0% 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 the Mo% is less than 0.3%, the above effects cannot be expected, and if the Mo% exceeds 3.0%, the toughness decreases, which is not preferable. V: 0.2 to 1.0% V exhibits the same action as Mo, and contributes to the improvement of the compressive strength as VC carbide. In addition, it contributes to the improvement of the compressive strength due to the miniaturization of primary crystals during centrifugal casting. If it is less than 0.2%, such an effect is too small, while if it exceeds 1.0%, cast segregation occurs in the composition range of the present invention, resulting in embrittlement of the material.

[0010] The cast iron material for a spool according to the present invention is formed of Fe and unavoidable impurities in addition to the above components. Since P and S deteriorate the toughness, it is desirable that P and S are as small as possible, and it is better to keep both of them at 0.2% or less. When the take-up spool has a composite structure, an outer layer is formed of the high compressive force cast iron material, and the inner layer joined to the inner peripheral surface of the outer layer is formed of ductile cast iron, adamite material (high carbon cast steel).
It is preferable to use an iron-based tough material such as graphite steel or high chrome cast steel. Examples of these preferred melt components are shown below. The unit is% by weight, and the balance is substantially Fe. (1) Ductile cast iron C: 2.5 to 4.0%, Si: 1.3 to 3.5%, Mn: 0.2 to 1.5% P: 0.2% or less, S: 0.2% or less, Ni: 0.5 to 3.0% Cr: 2.0% or less, Mo : 2.0% or less Mg: 0.02 to 0.1% (2) Adamite material C: 1.0 to 2.5%, Si: 0.5 to 1.5%, Mn: 0.2 to 1.5% P: 0.2% or less, S: 0.2% or less, Ni: 1.5 % Or less Cr: 2.0% or less, Mo: 2.0% or less (3) Graphite steel C: 1.0 to 2.3%, Si: 0.5 to 3.0%, Mn: 0.2 to 1.5% P: 0.2% or less, S: 0.2% or less, Ni: 0.5 to 3.0% Cr: 2.0% or less, Mo: 2.0% or less (4) High chrome cast steel C: 0.8 to 1.2%, Si: 0.3 to 1.0%, Mn: 0.3 to 1.0% P: 0.03% or less, S: 0.03% or less, Ni: 0.4 to 1.5% Cr: 11 to 12%, Mo: 2.0% or less In general, a centrifugal casting method is suitable for manufacturing the spool of the present invention. It is. When the spool has a composite structure, the outer layer and the inner layer are compounded by casting the outer layer by centrifugal casting, then pouring the inner layer material molten metal onto the outer layer inner peripheral surface, and welding the outer layer and the inner layer. The integration method is simple. In order to prevent Cr from being mixed from the outer layer to the inner layer when the outer layer and the inner layer are welded, an intermediate layer may be formed by welding on the inner surface of the outer layer, and the inner layer may be welded to the inner surface. As the intermediate layer material, the above-mentioned adamite material is suitable.

Further, 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 spool material in which the outer layer and the inner layer are joined is subjected to a heat treatment for improving the compressive strength and reducing the residual stress. Are roughly classified into this heat treatment, repeated several times tempering at a temperature of _three points A, how to bainite structure to decompose the residual austenite at high temperature of at least _three points A, it was heated again to the austenite region, the supersaturation After the dissolved C and Cr are precipitated as secondary carbide,
There is a method in which the matrix is made into tempered martensite by quenching / tempering heat treatment at a controlled cooling rate by spray water cooling or forced air cooling (austenite instability and quenching / tempering). By such a heat treatment, the base structure can be selected from bainite to tempered martensite.

Next, outer diameter φ800 mm, inner diameter φ600 mm, body length 10
A specific example of the 00 mm take-up spool will be described. (1) The melt of the outer layer material of the embodiment of Table 1 (A) is cast into a cylindrical mold rotating on a centrifugal casting machine, and after casting the outer layer, the melt of the adamite material described in the same table is cast on the inner surface thereof. , Forming an inner layer. The casting material had a black scale outer diameter of 820 mm, a black scale outer layer thickness of 90 mm, and a black scale inner diameter of 570 mm. The composition of the inner layer after welding is shown in Table 1 (B).

[0014]

[Table 1]

(2) In the example , only strain relief annealing was performed at 700 ° C. for 8 hours. After that, finishing was performed to obtain a product spool. (4) Table 2 shows the mechanical properties of each layer after the heat treatment.

[0016]

[Table 2]

As is clear from the examples shown in Table 2 , the compressive strength of the outer layer is as large as 137 kgf / mm ^2, and that of the conventional cast steel is 90 kgf / mm.
Although it was about ² mm ² or less, a remarkable improvement in compressive strength was observed. That is, although the material of the present invention was thick, it had extremely good hardenability, no casting defects, and a good welded state between the outer layer and the inner layer.

[0018]

As described above, since the outer layer of the strip take-up spool of the present invention is formed of a high-compression-strength cast iron material having a specific composition, the spool can be formed to have a large wall thickness. Elastic deformation and plastic deformation are unlikely to occur with respect to the tightening force generated by the above, thereby preventing the occurrence of winding wrinkles and enabling the mandrel to be smoothly attached and detached. By forming the inner layer of the outer layer of the spool using an iron-based tough material, impact resistance and durability are improved.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C22C 37/00-38/60 B21C 47/28

Claims (1)

(57) [Claims] 1. Chemical composition in weight%, C: 0.9 to 1.5%, Si: 0.5 to 1.5%, Mn: 0.5 to 1.5% Ni: 2.0% or less, Cr: 9 to 20%, Mo: 0.3 to 3.0% % V: 0.2 to 1.0% and the balance is substantially made of high-compression-strength cast iron material composed of Fe
The inner layer made of iron-based tough material is in contact with the inner peripheral surface of the formed outer layer.
Strip take-up sp characterized by being formed together
Rules.