JPH0462802B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for rolling titanium alloy plates, and more particularly to a pack rolling method that has successfully improved productivity.

[Prior Art] The pack rolling method is a method used as a technique for manufacturing thin titanium alloy plates. This rolling method involves stacking a plurality of titanium alloy plates to be rolled, covering the top, bottom and all sides of the plates with steel plates of an appropriate thickness, and welding the steel plates together to form a pack member (hereinafter referred to as After that, rolling is performed. That is, a pack containing titanium alloy plates is heated in a heating furnace, and then the whole pack is hot rolled, and then the steel plate is removed to produce a thin titanium alloy plate. Further, a plurality of air vent holes are formed in the front and rear end surfaces of the pack in the rolling direction for the purpose of preventing the air inside the pack member from being compressed during rolling and increasing the internal pressure.

In pack rolling, mainly α-type and α+β
The target type is titanium alloy. In other words, pure titanium and β-type titanium alloys can be manufactured by cold rolling, so pack rolling is not performed, while α-type and α+β-type titanium alloys are almost impossible to manufacture by cold rolling, so pack rolling is performed. It is necessary to do this. Further, the reason why cold rolling is impossible for α-type and α+β-type titanium alloys is as follows.

The cold rolling of the crystal orientation (close-packed hexagonal crystal system) deteriorates the bendability, making it impossible to produce a material that satisfies the bending specifications of the material.

If the cold rolling rate is set to about 20 to 30%, cracks will occur, so intermediate annealing must be performed frequently.

[Problems to be solved by the invention] Generally, rolling equipment used for bulk rolling of titanium alloy plates is also used as equipment for rolling relatively long objects such as slabs of steel plates and aluminum plates. Therefore, the beam pitch of the walking beam in the heating furnace or the roller pitch of the transfer roller table is also considerably larger than the pack.
In other words, in the conventional pack rolling of titanium alloy sheets, each pack is rolled, but because the titanium alloy sheet material is cross-rolled to make a standard size sheet, the width and length are around 1 m. It is relatively short. Therefore, even if an attempt is made to roll a small pack enclosing such a titanium alloy plate using the above-mentioned rolling equipment, it will not be able to reach between the pitches as it is.
Therefore, a special frame jig used for rolling the titanium alloy plate is required, which causes various inconveniences both in terms of equipment and work. Furthermore, since rolling is performed for each pack, productivity is also low.

In order to solve the above-mentioned problems, it may be possible to simply connect multiple packs and perform pack rolling, but in that case, the so-called fishtails that occur at the ends of the titanium alloy plate during rolling may interfere with each other. Other problems may occur if the packs are damaged or the edges of the titanium alloy plate are bent and bent between the pitches.

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a method for rolling titanium alloy that can be easily and efficiently carried out.

[Means for Solving the Problems] The structure of the present invention that can solve the above problems is summarized in that, when rolling a titanium alloy in packs, a plurality of packs are connected by a hollow connecting member and rolled. It has the following.

[Function] When rolling titanium alloy plates in packs, by adopting a configuration in which multiple packs are connected and rolled with a hollow connecting member, problems occur between the titanium plates housed in the connected packs. The fish tail portions are absorbed into the hollow portion of the hollow connecting member and are prevented from interfering with each other. That is, by being rolled, the titanium alloy plates in the pack extend together with the pack in the rolling direction, but both ends of the titanium alloy plates enter into the hollow portion of the hollow connecting portion with a margin. Therefore, there is no mutual interference, and the above-mentioned problems can be solved.

In order to effectively achieve the above effect, the length of the hollow portion of the hollow connecting member in the rolling direction must be long enough so that the fishtails generated at both ends of the titanium alloy plate do not interfere with each other when the titanium alloy plate is rolled. It is necessary to set it to Since the length of the fishtail can be predicted based on the rolling ratio, thickness, deformation resistance, etc. of the titanium alloy plate, the length of the hollow portion may be determined so as to absorb the length of the fishtail.

In the present invention, it is not only possible to connect two packs, but also to connect three or four packs. As a result, it can be made long enough to reach between the pitches of the existing rolling equipment, and equipment used only for titanium alloy rolling, such as a dedicated frame jig that was conventionally required during rolling, becomes unnecessary. In addition, since multiple packs can be connected and operated, multiple titanium alloy plates can be rolled at the same time.
Productivity will also improve.

[Example] An example of the present invention will be described with reference to the drawings. Ti
-6Al-4V titanium alloy plate 1 (thickness 12 mm,
Three titanium alloy plates (width: 960 mm, length: 800 mm) were stacked together, and the top, bottom, and all sides of the titanium alloy plate 1 were covered with mild steel having a thickness of 12 mm. Pack 2 at this time is formed by welding, and its external dimensions are 65 mm thick, 1000 mm wide, and 1000 mm long.
It is 850mm. Two packs 2 are prepared, and both ends of the packs 2 in the length direction are connected via a hollow connecting member 3, and the thickness is 65 mm, the width is 1000 mm, and the length is 65 mm.
Rolled material 4 of 1900 mm double pack was manufactured. The metal material of the hollow connecting member 3 at this time is the same mild steel as the material used for the pack.

A double pack rolled material 4 produced in this manner is shown in FIGS. 1-3. Fig. 1 shows the rolled material 4
2 shows a sectional view taken along the cutting line - of FIG. 1, and FIG. 1 3 shows a sectional view taken from the cutting line - of FIG. 1. Further, holes 6 for air venting are formed at predetermined locations on the end face of the pack 2 in the rolling direction, and air vent holes 7 are also formed on the end face of the hollow connecting member 3. 10 in FIG. 1 indicates the welded portion of the pack 2.

As described above, the length of the hollow portion 3a of the hollow connecting member 3 needs to be set to a length that can sufficiently absorb the fishtail portion generated during rolling of the titanium alloy plate. The rolling (reduction) rate of titanium alloy plate is usually
It is approximately 70 to 80%, and in this case, the fishtail portion generated at the end of one titanium alloy plate is approximately 50 mm. For example, if the rolling ratio is 75%, the rolling ratio will be 4. Therefore, assuming that the total length of the fishtail part generated from both packs is 100 mm, considering that the rolling ratio of the hollow connecting member 3 is also about the same, the connecting member The length of the hollow part 3a in 3 is 100/4=
25 (mm). That is, in this case, the hollow portion 3a
The length in the rolling direction (horizontal direction in Figure 1) must be at least 25 mm. In this way, the length of the hollow portion 3a of the hollow connecting member 3 can be set. In the embodiment shown in FIG. 1, the length of the hollow connecting member 3 was 200 mm.

The rolled material 4 shown in FIGS. 1 to 3 is heated to 950°C in a heating furnace equipped with a walking beam,
After that, without using special jigs such as a dedicated frame jig, the existing hot rolling mill was used to roll the product to a thickness of 15 mm and a width of 1000 mm.
It was rolled to a length of 7000mm. After that, by dismantling Pack 2, the thickness is 3mm, width is 960mm, and length is 320mm.
A Ti-6Al-4V titanium alloy rolled plate was obtained.
In other words, one rolling process produces 3 pieces for each pack, a total of 6 pieces.
This means that two titanium alloy plates have been manufactured. Furthermore, no interference was observed between the fish tails at both ends of the titanium alloy plates, and a good titanium alloy rolled plate could be obtained.

[Effects of the Invention] As described above, according to the present invention, the length of the rolled material can be secured by adopting the above-described configuration, and a special jig such as a dedicated frame jig is separately prepared. There was no need to do this, and good rolling was possible using the existing rolling equipment. In addition, the fishtail generated during rolling can be absorbed by the hollow part of the hollow connecting member, so there is no damage to the pack or bending of the titanium alloy plate, and it is possible to roll multiple packs at the same time, increasing productivity. This can greatly contribute to improvement.

[Brief explanation of drawings]

1 is a plan view of a rolled material 4 constructed according to the present invention, and FIG. 1 2 is a section line of FIG.
FIG. 1 is a sectional view taken along the cutting line - in FIG. 1. 1...Titanium alloy plate, 2...Pack (member),
3...Hollow connecting member, 3a...Hollow portion, 4...
Rolled material.

Claims (1)

[Claims] 1. A method for rolling a titanium alloy plate, characterized in that when rolling a titanium alloy in packs, a plurality of packs are connected by a hollow connecting member and rolled.