JPH02182303A - Rolled stock for pack rolling - Google Patents

Abstract

PURPOSE:To perform stable pack rolling by lapping a cover stock on both top and bottom surfaces of a core stock and putting a spacer stock between both cover stocks at both ends of the core stock and boring gas vent holes in upper and lower cover stocks at both end parts in the lateral direction of the core stock. CONSTITUTION:Gas vent holes 5 are bored in a cover stock 2 facing to both lateral ends of a core stock 1 contained in the cover stock 2 and a spacer stock 3. When the total stock is pack rolled, the core stock 1 and the cover stock 2 elongate along the rolling direction and lateral elongation of the stocks is hardly generated. By that, after rolling, the holes 5 are located in the core stock 2 facing to both ends of the stock 1 and are not crushed by rolling because the holes 5 are bored in the thickness direction. A hardly workable material, such as a titanium alloy or high alloy, etc., is used as the core stock 1 and an easily workable material, such as carbon steel, etc., is used as the cover stock 2.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a pack rolling material used when laminating difficult-to-work materials such as titanium alloys and high-alloy steels with different materials and rolling them in packs. .

[Conventional technology]

Materials such as titanium alloy and Inconel have high deformation resistance;
It is difficult to form it into a predetermined shape by rolling. Therefore, after sandwiching this difficult-to-work material with easy-to-work materials such as carbon steel 3541 and pack-rolling the laminate,
The core material is separated from the cover material and spacer material to produce a plate material with a predetermined thickness.

The core material and cover material in this pack rolling material are:
They are just superimposed on each other. Further, since different materials are used as the core material and the cover material, the elongation during rolling differs between the core material and the cover material, making it easy for slippage to occur between the two. Furthermore, when rolling a material in which a plurality of core materials are overlapped with a cover material, slippage also occurs between the core materials. Therefore, slippage is likely to occur between the two, and the shape after rolling is more likely to deteriorate than in normal rolling for solid materials.

In order to prevent this shape deterioration, for example, JP-A-63-7
In Japanese Patent No. 2405, the temperature of the outer core material is heated to be higher than the temperature of the inner core material to correct the temperature distribution due to cooling during rolling. Also, JP-A-63-72406
In the publication, the inner core material is made thicker (
However, the finished plate thickness is matched. Furthermore,
In JP-A-63-80903, the materials and rolling temperature of the core material and the cover material are selected so that the deformation resistance value of the core material is greater than the deformation resistance value of the cover material.

[Problem to be solved by the invention]

The materials targeted by pack rolling are as shown in Figure 3.
A core material 1 is wrapped in a cover material 2 and a spacer material 3. Then, the cover material 2 and the spacer material 3 are welded 4, and the core material is placed at a predetermined position inside. Therefore, voids in which gas such as air exists are created inside the rolling material.

When this rolling material is heated to a high temperature that enables pack rolling,
The gas inside expands and pushes up the cover material 2, making the heating and rolling conditions unstable. In extreme cases, the expanded gas may destroy the weld 4 between the cover material 2 and the spacer material 3, making it impossible to perform normal rolling. Further, during rolling, the voids inside the material are compressed, and the pressure of the gas trapped inside increases accordingly. Since this pressure increase acts on the cover material 2 whose thickness has been reduced by rolling, the cover material 2 becomes more likely to break. Since the core material 1 comes into contact with the outside air at the location where the cover material 2 breaks,
Partial rapid cooling occurs, increasing deformation resistance and reducing plate thickness accuracy after rolling.

Therefore, the present invention provides degassing holes that communicate with the inside of the pack rolling material at positions corresponding to both ends of the core material of the cover material, so that the pressure is increased by the gas expanded by heating before rolling and the compression during rolling. The purpose of the present invention is to provide a pack rolling material capable of releasing gas from the inside of the pack rolling material and producing plate materials of excellent quality under stable conditions.

[Means to solve the problem]

In order to achieve the object, the pack rolling material of the present invention includes a core material, a cover material stacked on both upper and lower surfaces of the core material, and a material located at both ends of the core material between the cover materials.
A pack rolling material consisting of a spacer material provided with gas vent holes in the upper cover material and/or the lower cover material so as to be located at positions corresponding to both ends in the width direction of the core material. It is characterized by

[Effect]

In order to release the gas inside the rolling material to the outside, gas vent holes may be provided in the cover material 2 or the spacer material 3 shown in FIG. 3. However, the gas vent holes provided in the spacer material 3 are crushed by rolling, and the passage through which the gas trapped inside the material escapes is blocked.

Furthermore, even when gas vent holes are provided in the cover material 2, if the gas vent holes are drilled at locations where the upper and lower cover materials 2 are crimped during rolling, the gas vent holes will be similarly removed by rolling. crushed.

Therefore, in the present invention, as shown in FIG.
is installed. When this material is pack-rolled, the core material 1 and the cover material 2 are elongated along the rolling direction P, but the material hardly elongates in the width direction. Therefore, even after rolling, the gas vent holes 5 are located in the portions of the cover material 2 facing both ends of the core material 1, as shown in FIG. Further, since the gas vent holes 5 are formed in the thickness direction of the material, they are not crushed by rolling.

As the core material 1, a difficult-to-work material such as titanium alloy or high alloy steel is used. On the other hand, as the cover material 2, an easily processable material such as carbon steel is used.

Therefore, when the material shown in FIG. 1 is rolled, the elongation of the core material 1 and the cover material 2 is different, so that the relative position of the gas vent hole 5 with respect to the core material 1 moves as shown in FIG. 2. At this time, if the gas vent hole 5 is bored at a position away from the longitudinal end of the core material 1, the gas vent hole 5 will be blocked by the upper and lower cover materials 2 being crimped during rolling. , the desired effect is not achieved.

In order to prevent this clogging, the position of the gas vent hole 5 in the longitudinal direction is set so that the gas vent hole 5 is located at the longitudinal end of the core material l or inside thereof in the state after rolling. There is.

Specifically, the distance io from the longitudinal end of the core material l at the material stage to the drilling position of the gas vent hole 5 is determined as follows. When the material thickness of the cover material 2 is To and the final thickness is T, the rolling reduction ratio α of the cover material 2 is calculated by the following formula (1
).

α”T o / T, ...(1
) Also, the material thickness of the core material 1 is t. When the final thickness is tl, the rolling reduction ratio β of the core material 1 is expressed by the following equation (2).

β= to/t + ・ ・ ・
- (2) Therefore, the core material 1 having a length Lo is elongated to β×Lo after rolling. On the other hand, the cover material 2 located at a distance of 10 at the material stage is αx('/ALo go
). Therefore, in order to position the gas vent hole 5 at the longitudinal end or inside of the core material 1 in the state after rolling, as shown in FIG.
A gas vent hole 5 is bored at the position β0.

a x(Z L+l fo) ≦βx! ,4Lo
l H1・(3) As a result, the gas vent holes 5 are not crushed during rolling, and allow the inside of the material to communicate with the outside until the end of rolling, forming a passage through which the gas compressed inside the material is dissipated. . In addition, at the stage of heating the material before rolling, the expanded gas inside is released through the gas vent hole 5, so the pressure inside the material does not become high. As described above, when the back rolling material of the present invention is used, degassing can be carried out smoothly during the heating stage and the rolling stage, so that the cover material 2 does not break and a product with a good rolled shape can be obtained. .

The gas vent hole 5 provided in the cover material 2 is also used as a guide for determining the cutting line when separating the core material 1 from the cover material 2 after back rolling. That is, although the material for back rolling is stretched and thinned in the rolling direction P, there is almost no movement of the material in the width direction. Therefore, the positional relationship between the core material l and the gas vent holes 5 in the width direction does not change before and after rolling. Further, since the gas vent holes 5 are provided in the thickness direction of the material, they are not crushed by rolling.

Therefore, the gas vent holes 5 can be easily identified even after rolling, and the gas vent holes 5 indicate the positions of both ends of the core material 1. Therefore, when cutting the cover material 2 along the lines a and b connecting the gas vent holes 5 in the rolling direction, it is possible to separate the core material 1 and the cover material 2 without cutting off the ends of the core material 1. can. On the other hand, if there is no guideline such as the gas vent hole 5, it becomes necessary to cut the core material 1 slightly inwardly along the rolling direction after rolling, and the yield decreases accordingly.

The core material 1 accommodated inside the cover material 2 and the spacer material 3 may be one or a plurality of core materials stacked one on top of the other. However, when assembling a rolling material by overlapping a plurality of core materials 1, it is preferable to fix the longitudinal ends of the core materials 1 to each other by means such as welding. As a result, the mutual positional relationship among the plurality of core materials 1 is determined, and even if shearing force is applied during rolling, no misalignment occurs between the core materials 1. Therefore, each core material l receives the rolling blade evenly,
In particular, it is possible to avoid uneven thickness at the beginning or end of the core material 1.

Further, in order to prevent the cover material 2 from breaking during rolling, it is preferable to select the material thickness of the cover material 2 so that the thickness of the rolled cover material 2 is 5 mm or more.

Generally, products to which back rolling is applied have a plate thickness of approximately 611 mm.
It is a thin material with a diameter less than 1111, and has very high deformation resistance as seen in titanium alloys. Therefore, when the shape of the rolled plate material is bad, it is difficult to correct the shape of the plate material by cold work. In this respect, it is necessary to produce a finished shape by pack rolling in a good shape. Furthermore, when the thickness of the cover material 2 becomes extremely thin, the temperature of the cover material 2 decreases greatly, the buckling strength decreases, and waves are likely to occur. Furthermore, the cover material 2 becomes more likely to break due to a decrease in strength due to the reduction in cross section. From such a thing,
The thickness of the cover material 2 is set in the range of 15 to 25 mm at the material stage.

However, simply by specifying the thickness of the cover material 2 at the material stage, the generation of waves in the product is still unavoidable. In other words, the cover material 2 needs to have a thickness that will maintain the flatness of the core material 1 and maintain the shape of the material, especially in the later passes of rolling. In this respect, covering material 2
The plate thickness after rolling has a greater influence on pack rolling than the material thickness.

〔Example〕

Examples will be described below.

Example 1 - Inconel 625 material (thickness 21mm, width 26mm)
50+oIB.

Length. ) as core material 1, and 5S on top and bottom of it.
Cover material 2 made of 41 (thickness 45mm, width 2B00m)
m) was overlapped. This cover material 2 has a distance #IiI! from the longitudinal end of the core material l. . Gas vent holes 5 were provided at four locations. The material assembled in this way (total thickness 132
mm) was pack-rolled to a final thickness of 18 aa (core material 1 thickness: 6 rolls/sheet, cover material 2 thickness: 3 rolls/sheet).

Table 1 shows the positions of the gas vent holes 5 before and after rolling. However, the distance i in the same table
The minus value of o indicates the case where the gas vent hole 5 comes out from the longitudinal end of the core material 1 after rolling.

Table 1 Change in position of gas vent holes due to rolling (IIIll
) Even after rolling, the gas vent holes 5 are located at both ends of the core material l,
Alternatively, when the material of test Nα3 provided in the cover material 2 is pack-rolled so as to be at least at the longitudinal end, the gas in the voids formed inside the material is smoothly dissipated to the outside, and the rolling A product with a constant thickness was obtained without any problems.

On the other hand, in test No. 1.2 in which the gas vent hole 5 was located outside the longitudinal end of the core material 1 after rolling, the cover material warped due to the gas pressure near the final pass of rolling. . In addition, some thickness variations were observed at the longitudinal ends of the core material 1.

Example 2 - Titanium alloy material containing 6% by weight of Al and 4% by weight of V (thickness 7mm, width 1910+m, length Lo)
Two sheets were stacked as core material L, and cover material 2 made of 5S41 (thickness Tic, width 2030+ni) was stacked above and below. This cover material 2 has gas vent holes 5 at four locations from the longitudinal end of the core material l to positions that satisfy the above-mentioned formula (3).
was set up. The materials assembled in this way were pack-rolled to a final thickness of 18mm (core material thickness 1.6mm/
). The gas vent hole 5 after rolling was located at the longitudinal end of the core material I.

Table 2 shows the relationship between the thickness of the cover material 2 and the product shape before and after rolling.

As is clear from this example, the gas vent hole 5 is set at a position that does not protrude from the core material l even after rolling,
By ensuring the thickness of the cover plate 2 after rolling is 5 mm or more, a product with a good shape can be obtained.

〔Effect of the invention〕

As explained above, according to the present invention, by providing the cover material with gas vent holes that communicate the internal space around the core material with the outside both before and after rolling, heat treatment prior to rolling can be carried out. During the rolling process, the expanding gas escapes from the inner space of the material to the outside through the vent holes, and the gas compressed during the rolling stage also escapes. Therefore, the inside of the material will not be in a high pressure state, and the joint between the cover material and the spacer material will not be destroyed.
Pack rolling is carried out under stable conditions, resulting in products with excellent shapes.

[Brief explanation of the drawing]

FIG. 1 is a plan view for explaining the pack rolling material of the present invention, and FIG. 2 shows the material in a rolled state. On the other hand, it indicates extended use material. l: core material 3 varnish spacer material 5; gas vent hole β. : Distance of gas vent hole a, b: Cutting line in Fig. 3 is as follows: Conventional pack pressure 2: Cover material 4: Welded part P: Rolling direction Lo = Material length of core material

Claims (1)

[Claims] 1. A pack rolling material consisting of a core material, a cover material stacked on both the upper and lower surfaces of the core material, and a spacer material located at both ends of the core material and provided between the cover materials, A material for pack rolling, characterized in that degassing holes are provided in the upper cover material and/or the lower cover material so as to be located at positions corresponding to both ends in the width direction of the core material.