JPH07108405B2 - Pack rolling method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a laminated rolling (packing for producing wide and thin materials of non-ferrous metal such as pure Ti and alloy Ti and high alloy steel by hot rolling. Rolling) method.

[Prior art] Generally, in non-ferrous metals such as pure Ti and alloy Ti, and high alloy steels, there are many so-called difficult-to-process materials such as insufficient cold ductility and high deformation resistance. Is manufactured by
It is often very difficult due to problems such as cracking, milling capacity and rolling efficiency.

Further, even in hot rolling these metals, in order to adjust the structure of the product, to keep the hot rolling temperature within a certain range, in order to eliminate the rolling anisotropy as seen in alloy Ti Although there are demands such as performing cross rolling, ordinary tandem strip mills often cannot satisfy this demand. Therefore, it is difficult to manufacture a thin plate even in hot rolling.

Therefore, in order to solve these problems, stack rolling (pack rolling) has been conventionally performed.

The pack rolling method described here uses a desired material as a core material, and covers the upper and lower and four corners of the core material with a cover material and spacers and welds the surroundings to assemble the packed material and hot-roll it, and then disassemble the packed material. Then, it is a method of manufacturing a thin plate of the core material.

FIG. 1 schematically shows the shape of the pack.

In the figure, 1: core material, 2: cover material, 3: spacer, 4: welded part.

However, there is no systematic research on this method,
There is no knowledge about the dimensions of the cover material and the core material and the selection method of the material, and it is the current situation that the manufacturers rely on their cans, and the following problems occur.

(1) As a selection method of the cover material and the core material, in order to select a material and a rolling temperature range in which the deformation resistances of both are as close as possible,
The combination is limited. For this reason, the materials to which this method can be applied are limited, and it is not possible to manufacture thin plates of arbitrary materials.

(2) When the selection or combination of the cover material and the core material is inappropriate, the core material is corrugated inside the pack, and in some cases, the core material is folded and overlapped, and a product cannot be obtained. In addition, a step for correcting the corrugation is required, which is inefficient and causes a cost increase.

[Problems to be solved by the invention]

The present invention, wide non-ferrous metals and high-alloy steels, such as pure T _i or alloy T _i, when thin materials the (5mm or less) manufactured by hot rolling to prevent the occurrence of shape defect due to the rolling of the core material An object of the present invention is to provide a pack rolling method that improves the efficiency of thin plate production and reduces costs.

[Means for solving problems]

The present invention is a thin material in which one or more core materials coated with a release agent on the surface are laminated, the upper and lower parts thereof are covered with a cover material, and the surroundings are surrounded by a spacer and welded to assemble a laminated rolling material, which is hot rolled. In the manufacturing method, the core material and the cover material are selected so that the deformation resistance value of the core material is equal to or less than the deformation resistance value of the cover material, and the ratio of the thickness of the core material to the total thickness of the assembled material is 0.65 to 0.82. It is a pack rolling method characterized by the above.

[Action]

As described above, FIG. 1 schematically shows the structure of the laminated rolled material in cross section.

Here, the core material 1 is a plate made of a material to be thinned, and one or more sheets each having a surface coated with a release agent are stacked.

The release agent is for preventing the core materials and the core material and the cover material from adhering to each other by rolling, and any release agent may be used as long as it satisfies this requirement.

The top and bottom of the core material 1 are sandwiched by the cover material 2, and the periphery thereof is surrounded by the spacer 3. The cover material 2 and the spacer 3 are welded over the entire circumference to prevent the cover material 2 from peeling off during rolling and breaking of the laminated rolling material. The laminated rolled material is filled with air or other gas, or in a vacuum atmosphere.

Here, the cover material deformation resistance value k _s core material deformation resistance value k _i laminating plate thickness ratio core material thickness / total plate thickness The inventors conducted research on laminated rolling, and as a result, When the material to be rolled is hot-rolled, the deformation resistance values k _s and k _{i of} the cover material 2 and the core material 1 are different, so the respective reduction amounts are different and the laminated plate thickness ratio before and after rolling is different. It was confirmed experimentally that the phenomenon occurred.

When k _s <k _i, the cover material 2 has a smaller deformation resistance than the core material 1, so that the cover material 2 has a larger rolling reduction than the core material 1 and a larger elongation in the rolling direction due to the rolling. The core material 1 does not become defective in shape because the core material 1 does not get stuck in the spacer 3.

When k _s > k _i The core material 1 is crushed from the cover material 2 by rolling, and the core material 1
Is longer than that of the cover material 2, the core material 1
Is replaced by spacer 3 and there is no place for core material 1,
Phenomena as shown in FIGS. 2 (a) (b) (c) occur.
That is, (a) if the welded portion 4 of the cover material 2 is weak, the core material 1 pushes the spacers 3 and the laminated rolling material is destroyed. In this case, it becomes impossible to continue rolling thereafter. (2) (a) and (b) If the core material 1 is thin and easily buckles, the core material 1 will buckle to the spacers 3, resulting in a wavy shape defect. If the rolling is further continued, the core material will be folded and overlapped. In this case, a thin plate having a good shape cannot be obtained, and the product cannot be manufactured. ...... Fig. 2 (b) (c) When the core material 1 and the cover material 2 are balanced in strength, the core material 1
Pushes the cover material 2, both of them extend at the same time, and a flat plate can be obtained without breaking the laminated rolling material. ... Fig. 2 (c) Experimentally shows the above phenomenon.

Using SS41 as the cover material and pure Ti as the core material, various rolling ratios and total plate thicknesses were changed, and hot rolling experiments were conducted.

After rolling, the pack was disassembled, the core material was taken out, and the steepness thereof was measured. The results are shown in FIG. Rolling temperature is 750
Since it was set to ℃, the deformation resistance of pure Ti <SS41,
This corresponds to the case of k _s > k _i .

As a result, when the laminated plate thickness ratio exceeds 0.82, Fig. 2 (a)
It can be seen that the pack is destroyed as shown in.

It can be seen that when the laminated plate thickness ratio is less than 0.65, the core material is corrugated and the shape is defective, although there is a degree of difference depending on the total plate thickness. When the thickness ratio of the laminated plates in FIG. 2 (b) is between 0.65 and 0.82, the flat plate can be obtained without breaking the pack. From FIG. 2 (c), it can be seen that when the cover material has a larger deformation resistance than the core material, a flat plate can be obtained by configuring the pack so that the laminated plate thickness ratio is 0.65 to 0.82.

Next, examples of the present invention will be described.

〔Example〕

(1) Pack structure Cover material: Mild steel C Equivalent: 0.03% Laminate thickness ratio No.1 68.0t × 1280w × 1800lmm 0.33 No.2 11.3t × 1280w × 1800lmm 0.75 Release agent NaOH 1% Al ₂ O ₃ 200g in 50cc, casein 0.3
g Apply the mixture.

The assembly dimensions are shown in Fig. 4 (plan view) and Fig. 5 (cross-sectional view).
As shown in.

(2) Rolling conditions Heating temperature rises at 100 ℃ / hr, 3.5Hr hold at 900 ℃ Rolling temperature approx. 850 ℃ Deformation resistance value SS41: approx. 20kgf / mm ² Pure Ti: approx. 15kgf / mm ² (3) State of core material No.1 Core material is not folded and cannot be used during rolling. It cannot be used as a defective product. No.2 An entirely flat core material can be obtained. Was obtained.

〔The invention's effect〕

The pack rolling method of the present invention has the following effects.

(1) Since the method of selecting the cover material and the core material can be freely selected, the pack rolling method can be applied to any material and thin plate manufacturing can be performed.

(2) Shape defects such as corrugation of the core material are eliminated, the efficiency of thin plate production is improved, and the cost is reduced.

(3) As long as the conditions shown in the present invention are satisfied, any number of core materials may be used.
It becomes possible to manufacture ultra thin plates.

(4) Basically, the constitution of the laminated rolled material shown in the present invention is
Since it is determined by the deformation resistance of the core material and the cover material, not only Ti but also other metals can be applied.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view showing a laminated rolling material structure of the present invention,
FIG. 2 is an explanatory diagram of three modes of the present invention in which k _s > k _i is laminated and rolled, and FIG. 3 is an explanatory diagram showing the relationship between the steepness and the laminated sheet thickness ratio, FIGS. 4 and 5. FIG. 3 is an explanatory diagram showing dimensions of a plane and a cross section at the time of assembling. In the figure, 1: core material, 2: cover material, 3: spacer, 4: welded part, 5: release agent. In the drawings, the same reference numerals indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Arizumi 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Toshinori Matsuo 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd. (72) Inventor Junzo Tamai 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd. (56) Reference JP-A-48-86762 (JP, A) JP-A-59 -42102 (JP, A)

Claims (1)

[Claims] 1. A thin material obtained by hot-rolling a laminated rolling material, which is obtained by laminating one or more core materials each having a release agent applied on the surface thereof, covering the upper and lower sides thereof with a cover material, enclosing a periphery with a spacer, and welding to assemble them. In the manufacturing method, the core material and the cover material are selected so that the deformation resistance value of the core material is equal to or less than the deformation resistance value of the cover material, and the ratio of the thickness of the core material to the total thickness of the assembled material is 0.65 to 0.82. A method for rolling a pack, comprising: