JP3270967B2 - Welding method of lining on site of titanium material and lining method of concrete structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for welding a lining of a titanium material at a site. Titanium, especially
The present invention relates to a method for performing on-site lining work of a concrete structure while preventing high-temperature air oxidation and denaturation of a material in TIG welding of a thin plate material.

[0002]

2. Description of the Related Art Chemical storage tanks related to water purification plants, which are commonly used, are of the underground pit concrete type, and most of them have a chemical resistant structure by rubber-lining the inside of the concrete tank. As a problem of such a structure, there is a problem of intermediate maintenance management such as abrasion of the driving body due to a chemical flowing out to a concrete driving body due to separation of a joint due to deterioration of a rubber lining.

[0003]

When a titanium material is used on the entire surface of the tank, titanium is strong against chemicals and durable. Although some chemicals are incompatible, titanium has a strong affinity for oxygen at high temperatures and is easily oxidized.
Where the temperature exceeds 00 ° C., a shield of argon gas is required. If the shield of the argon gas is not complete and oxidized, the titanium deteriorates and becomes unusable.
Therefore, the present invention sends argon gas to the back side of the panel,
The welding is performed in the state where the argon gas is replaced with air. As a result, a tank of titanium lining (all inner surfaces) of a concrete structure, which has been difficult to construct, is obtained.

[0004]

According to the present invention, in order to cover the entire inner surface of the underground chemical storage tank with a titanium material, a lining material which is a panel made of a titanium material prepared in advance is arranged on a concrete precursor. A front plate is applied so as to cover the joint on the front side of the joint between the lining materials, and a backing plate having a thickness equal to that of the lining material is fixed to an edge portion on the joint side on the back side of the lining material. The gap between the plates and the gap between the lining materials create a flow path of argon gas for shielding, and while feeding the argon gas into the flow path of the argon gas, the edge of the front plate is cut off. 2. The method of claim 1, wherein the lining is welded to a lining material and hermetically sealed, and the lining material is fixed to a concrete body by a grip anchor. The method relates to a titanium lining of concrete structures in.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A panel is made of a titanium material, and constitutes a lining material 1. The panel must be TIG-welded at its front seam, but this is done while sending shielding gas (argon gas) to the back to prevent oxidation. That is, the front plate 2 is placed on the joint, and the edge is welded. Front plate 2
It lies over the seams of the longitudinal and transverse panels or lining 1.

The backing plate 3 is fixed to the back side of the lining material 1. This backing material 3 creates a flow path 4 for argon gas to the weld. A shield gas (argon gas) is sent to the weld and replaced with oxygen (air).

The operation will be described below. A factory-manufactured panel is fixed with a grip anchor 5 inside a storage tank whose concrete surface has been finished in advance. Panels that have been dimensioned and factory-manufactured have a backing plate equivalent to the panel around the back surface, which is welded by cutting the edges and creating gas passages. The fixing bolt hole is also machined, and a donut plate having the same thickness as the panel, that is, a backing plate washer 6 'is also welded to the bolt hole.

[0008] An interval is provided between the panels (15 to 20 mm) through which the shielding gas passes, and the panel is fixed to the vehicle body with a grip anchor. After the panel is fixed to the bottom of the storage tank and the side about 1.5m, it is temporarily welded between each panel with a front plate, that is, an overlap plate, and cured with masking tape to prevent gas leakage from the temporary weld. I do.

After a series of operations as described above, argon gas is fed into the precursor 7 and the back side of the panel, and after it is confirmed that the air has been completely replaced with air, welding is started while removing the masking tape.

As described above, titanium has a strong affinity with oxygen at high temperatures, and a place where the temperature becomes 400 ° C. or more requires shielding of argon gas. If the shield is not completely oxidized, the ductility and malleability of the metal deteriorate significantly,
In addition, cracks occur due to an increase in hardness.

FIG. 1 is a view from the surface, showing an overlapping plate, that is, a state in which a front plate is over a seam, and 8 shows an edge of a front plate 2 which is a welded portion. .
That is, the front plate 2 is applied to the joint, and the edge thereof is welded to the lining material to seal.

[0012]

FIG. 2 is a view from the back, showing the backing plate 3 making a gas bribe.
The backing plate is pre-welded to the panel or lining plate to ensure a gas flow path 4. In addition, the backing plate not only creates a shielding gas flow path, but also has a space to prevent the thermal effect of directly touching the concrete of the lining material,
There is an effect as a dummy plate for preventing oxidation, and double safety for preventing oxidation is obtained.

FIG. 3 shows the grip anchor and its periphery, showing a state in which the anchor is firmly fixed to the vehicle body by bolts.

The lower right part in FIG. 1 shows a place where the anchor is fixed, and shows a state in which a donut plate or washer 6 is provided on a square plate 9 and fastened with bolts 10. still,
The lining material 1, the backing plate 3, and the square plate 9 are integrated (panel plate).

FIG. 4 shows the whole tank, showing a state where panels are stacked, and 5 shows a grip anchor.

FIG. 5 shows a state of the tank, in which the argon gas from the argon gas cylinder 11 is fed into the back of the inner surface, and is fed by one tube 12,
It is shown that the air is exhausted by another tube 13.

Since a small amount of argon gas is continuously supplied during the welding operation, special attention should be paid to the intake and exhaust of the inside of the storage tank, and prevention of oxygen deficiency is indispensable.

The precautions for the welding operation are as follows. Clean the welded surface and the surfaces on each side of 25mm or more with ethanol. Ethanol should not be left on metal surfaces. Store unused welding rods in storage containers. Tools for titanium are dedicated to titanium. Argon gas sealing is performed on all of the welding surfaces during welding and the surfaces at 400 ° C. or lower. The argon gas seal is
Keep flowing until cooled to 400 ° C or less. As the argon gas, a gas having a dew point of −50 ° C. or less and a purity of 99.975% or more is used. The heated end of the welding rod immediately after welding is 40
Argon gas sealing is performed until the temperature is reduced to 0 ° C. or less. When oxidized, the end of the welding rod 10 mm or more is cut off with pliers, and then the next welding is performed. Rubber hoses that may absorb moisture are not used for shielding gas. The temperature between passes is set to 150 ° C. or less. If the tungsten electrode comes into contact with the welding rod during welding, the welding is interrupted, a portion contaminated with tungsten is removed with a rotary bar or the like, and cleaning is performed, followed by re-welding. Welding should be done in clean work clothes and clean gloves. Preheating before welding and heat treatment after welding are not performed. The welding rod is
Clean with ethanol before welding.

[0019]

According to the present invention, it is possible to overcome the difficulty of welding titanium material and prevent the performance of titanium from deteriorating, and to make a titanium lining of a concrete structure.

[Brief description of the drawings]

FIG. 1 is a front view of a portion of FIG.

FIG. 2 is a back view seen from the back.

FIG. 3 is a front view around a grip anchor.

FIG. 4 is a front view of a tank.

FIG. 5 is a sectional view showing suction and exhaust of a tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lining material (panel board) 2 Front backing board 3 Backing board (panel board) 4 Gas flow path 5 Grip anchor 6 Washer 6 'Backing board washer (panel board) 7 Generator 8 Welded part 9 Square board (panel) Plate) 10 volts 11 argon gas cylinder 12 tube 13 exhaust tube

Continuation of the front page (56) References JP-A-9-226886 (JP, A) JP-A-56-131079 (JP, A) JP-A-10-300620 (JP, A) JP-A-7-84092 (JP, A) JP-A-9-301488 (JP, A) JP-A-63-70995 (JP, U) JP-A-2-11351 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B23K 9/00 B23K 9/16 B23K 9/167 B23K 9/23 C02F 1/00

Claims (2)

(57) [Claims] 1. An underground chemical storage tank is covered with titanium material so that the entire inner surface is covered with titanium material.
Arranging the lining material is made panels from the Raini
While that Table wear plate so as to cover the seam on the front side of the ring member mutual seam have those <br/>, the back side definitive seam side edge of the lining material
The backing plate is fixed in the lining material equivalent thickness portion, said
The gap between the backing plates and the gap between the lining materials
Making the flow path of the argon gas for shielding by 該A
A method of welding a lining on site of a titanium material to be sealed by welding an edge of a front plate to the lining material while feeding argon gas into a flow path of Lugon gas. 2. The method according to claim 1, wherein the lining material is fixed to the concrete body by a grip anchor.