JPS60215731A - Aluminum alloy for nuclear fusion device - Google Patents

Abstract

PURPOSE:To provide an Al alloy for a nuclear fusion device having excellent mechanical performance, weldability and electric resistance characteristic in combination by contg. Si, Mg, Cu and >=1 kinds of V and Cr respectively at prescribed ratios and consisting of the balance Al and unavoidable impurities. CONSTITUTION:An Al alloy for a nuclear fusion device contains, by weight %, 4.5-13% Si, 0.8-3.0% Mg, 0.2-1.6% Cu and further >=1 kinds of 0.05-0.3% V and 0.05-0.3% Cr and consists of the balance Al and unavoidable impurities. The content of Fe and Mn in the unavoidable impurities is preferably made as low as possible in terms of radioactivation. Mainly the plate material of the alloy of this invention can be manufactured by making a casting ingot by an ordinary method and subjecting the ingot to hot rolling, cold rolling and, if necessary, to annealing. Such plate is used after the plate is subjected in the final to a soln. heat treatment, hardening and again at an ordinary temp. The plate material has excellent mechanical performance (tensile strength, yield strength and elongation) and weldability and has >=5muOMEGA.cm electric resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structural aluminum alloy suitable for a nuclear fusion test device, particularly a vacuum vessel thereof.

Nuclear fusion reactors are being intensively researched as a means of creating next-generation energy following nuclear energy such as light water reactors. This nuclear fusion reaction (2 days dried 31-1 = 4 @e
In order to realize the condition of the sun on the ground through nuclear fusion reactions such as
seconds) must be created. The world is currently concentrating its collective wisdom on realizing this condition.

One such nuclear fusion reactor is a tokamak type reactor, which is shaped like a giant donut and uses a huge magnetic 6 (Holoidal magnet, toroidal magnet) is used to trap and hold it in the air using its magnetic force.

The vacuum container used here is conventionally made of Inconel (Ni).
-Or-Fe alloy: INGO Co., Ltd. trademark), stainless steel (SLJS 304, 316), etc. are used.

However, these elements (e.g., Ni, Go,
, Mn, Fe). Therefore, when Inconel or stainless steel is used for a vacuum container, D-T (2)
13 H) These components are activated by neutrons generated by the nuclear fusion reaction, producing gamma rays.

As a result, it becomes difficult for researchers and workers to access the device. There is also a method of remote control using a robot, but this requires a large amount of development cost and a long research period. Therefore, aluminum alloy materials, which are low activation materials, have attracted attention, and some JIS5052 grades (A, e'-2, 2 to 2.
8 wt% Mg-0, 15-0, 35 wt% Cr alloys) have been used in the past.

However, even the conventionally used aluminum alloy materials require many improvements. That is, removal of trace amounts of activated components, increase in material strength, improvement in weldability, electrical resistance characteristics, etc.

The following properties are required of aluminum alloy materials in the design of vacuum vessels.

1) Since it is a large structure, the strength of the material must exceed a specified level.

(Example 6 Tensile strength 28Kg/mm2 or more, Proof strength 12
Aim for b/#2 or higher. ) (2) The elongation of the material must be at least a certain level since it is made into a structure by bending a thick plate (plate thickness 30-50#).

(For example, aim for 13% or more.) (3) The electrical resistance of the material is high.

(Example: Aim for 5 μΩ・cm or more.) (4) Since each plate is joined by welding to form a structure, weldability must be good.

etc.

The main reason for increasing the electrical resistance of vacuum container materials is
This is because plasma current is excited inside the vacuum vessel by induction from the outside (holoidal magnet), so the one-round resistance value of the vacuum vessel needs to be equal to or higher than a predetermined value (for example, 0.1 TrLΩ).

Hitherto, there has been no aluminum alloy material that satisfies all of the above needs.

The present inventors completed the present invention as a result of intensive research into aluminum alloy materials that satisfy these requirements.

That is, in the present invention, Si 4.5 to 13 wt% (hereinafter wt
% is simply abbreviated as %), Mgo, 8-3.0%, C
uO2~1.6% and further VO,05~0.3%
, Cr in the range of 0.05 to 0.3%, and the remainder is unavoidable impurities.

By configuring the present invention in this manner, an aluminum alloy material having excellent mechanical performance, weldability, and electrical resistance characteristics can be obtained.

Next, the significance of the alloy additive elements of the alloy of the present invention and the reasons for their limitations will be described. Main additive element S' z M in the alloy of the present invention
g and Cu mutually affect strength, electrical resistance properties, etc.

Si is added to increase the strength and electrical resistance of the material, and is added in an amount of 4.5 to 13%. M(1, when Cu is in the following specified amount, if 3i is less than 4.5%, these are insufficient,
If it exceeds 13%, elongation will be insufficient and primary crystals S1 will appear, resulting in poor rolling workability.

M() is added to improve the strength of the material and increase the electrical resistance, and is added in an amount of 0.8 to 3.0%.S
When i'=Cu is a predetermined amount, if MQ is less than 0.8%, the strength will be insufficient and the electrical resistance will be small.

Moreover, if it exceeds 3.0%, elongation will be insufficient.

Cu is added in an amount of 0.2 to 1.6% to increase the strength and electrical resistance of the material. When 3i, M+J is a predetermined amount, if Cu is less than 0.2%, these properties are insufficient, and if it exceeds 1.6%, elongation is insufficient.

(2) or/and Or are intended to improve the strength by making the crystal grains of the base metal and the welded part finer, and are each 0.05 to 0.
One or two types are added within a range of 3%. If it is less than 0.05%, the crystal grains in the base metal and weld zone will become coarse, which is not preferable. Moreover, if it exceeds 0.3%, primary crystal giant intermetallic compounds are likely to occur, resulting in insufficient elongation.

In addition, ordinary unavoidable impurities (Fe,
Mn, Zn, Ti, Zr, etc.) are not particularly limited, but it is desirable to suppress Fe 11yln as much as possible from the viewpoint of activation.

Further, the alloy of the present invention, mainly a plate material, can be produced by forming an ingot using a conventional method, followed by hot rolling, cold rolling, and optionally annealing. These plates are finally solution-treated,
Quenched, aged at room temperature (condition 4) and used.

The plate made in this way has excellent mechanical performance (tensile strength, yield strength, -elongation) and weldability, and also has an electrical resistance of 5 μΩ·α or more.

The alloy of the present invention is mainly used in plate materials for nuclear fusion devices, but it is not limited to plates, and can also be used in structural materials such as extruded shapes, rods, and tubes.

The details of the present invention will be explained below based on examples.

Examples Table 1 shows tA (alloy is cast, SO,, (thickness) x
An ingot measuring 180 mm (width) x 180 mm (length) was obtained.

The A1 bullion used was 99.1% A.

After soaking at 520° C. for 24 hours, both sides were hardened (3 layers per side), heated to 500° C., and then hot rolled to a thickness of 3.5 mm. This plate was then annealed at 370° C. for 2 hours and then cold rolled to a thickness of 2.0 am+.

Finally, this cold rolled sheet was solution treated at 525° C. for 1 hour and then water quenched in room temperature water.

After aging this plate at room temperature for 4 days or more, it was subjected to a tensile test and an electrical resistance test. These results are also listed in Table 1.

For the welding test, a hot-rolled plate having a thickness of 3.5#Ill+ was solution-treated, quenched, and aged at room temperature under the same conditions as above. The results are shown in Table 1.

Note that these test methods are as follows.

a) Tensile test M: A test piece was taken in the board width direction (LTh direction) and tested.

b) Electrical resistance measurement: A test piece was taken in the longitudinal direction (L direction) of the plate and tested.

C) Weldability test: Thickness 3.511111s Length 300a
The e+ plate was butt welded by MIG welding. Regarding the weld length of 300ag+, the presence or absence of a crank in the bead portion was visually observed and determined. In addition, for the present invention alloy and the comparative alloy, the filler metal was JIS 4043 (A, e-4, 5-6.0% Si alloy).
I used welding wire.

Also, for comparison, commercially available conventional alloy JIS 5052
- For HI3 plates (thickness 2.0all and 3.5am), the test conditions were the same as above [However, in the welding test, J I 35356 (A, e
-4,5~5.5%M (1-0,05~0.20%Mn
-0,05~0.20%Cr -0,06~0.20
%■i alloy) using a welding wire), and the results are also listed in Table 1.

As is clear from Table 1, in terms of mechanical performance, the alloy of the present invention has a tensile strength of 28 to 9/2, a yield strength of 12 kg/#
It has an I#12 or higher, an elongation of 13% or higher, and an electrical resistance of 5.0 μΩ・cm or higher in both cases, confirming that it is an excellent material with no problems in terms of weldability.

In comparison, conventional alloys and comparative alloys are inferior to the invention alloy in either mechanical performance or electrical resistance.

As explained above, the alloy material of the present invention can be used in nuclear fusion test equipment,
It has a variety of outstanding properties that make it particularly suitable for the vacuum vessel.

Continued from page 1 0 Inventor Sai 1) Kane Tomi Shinsuna Research Institute, Arai-cho, Takasago City

Claims (1)

[Claims] Si 4.5-13%, MOo, 8-3.0%, Cu
O, 2-1.6% and further V O, 05-0.3%, Q
r Any one or two within the range of 0.05 to 0.3%
An aluminum alloy for use in nuclear fusion devices that contains seeds and the remainder consists of inevitable impurities and aluminum.