JPH09122742A - Manufacture of corrosion-proof steel pipe pile covered by metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain a corrosion-proof steel pipe pile having corrosion resistance with a long life by welding a retainer made of a titanium clad steel on the outer periphery of the lower part of the steel pipe pile, inserting a titanium sheath tube into the steel pipe pile, welding its end part and the clad steel, and filling a gap between the sheath tube and the steel pipe pile with a corrosion-proof material. SOLUTION: A retainer 9 is inserted into the outer periphery of the lower part of the band of a steel pipe pile 8 coming into contact with splashes and a tidal band, and is welded. The inside of the retainer 9 is made of a carbon steel and its outside is made of a clad material. Welding can be easily performed because they are steels. A titanium sheath tube 5 with an inside diameter almost the same as the outside diameter of the retainer 9 is inserted so that the splashes and the tidal bands of the steel pipe pile 8 are covered. The end part 5' of the titanium sheath tube 5 is welded to the retainer 9. Welding can be easily performed because they are titanium. A gap between the titanium sheath tube 5 and the steel pipe pile 8 is filled with a corrosion-proof material 12. A seawater-resistant insulating material is preferable for the corrosion-proof material 12. The corrosion resistance life of the corrosion- proof material 12 becomes long by the effect of the titanium sheath tube 5 excellent in corrosion resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a corrosion-resistant steel pipe pile coated with titanium having high corrosion resistance, and in particular, as a marine structure, a titanium material is used to coat a splash zone on the surface of seawater. The present invention relates to a method for manufacturing a steel pipe pile having excellent corrosion resistance.

[0002]

2. Description of the Related Art Conventionally, steel pipe piles that have been established in the sea as the basis of offshore structures are subject to a large amount of corrosion of the splash zone washed by seawater. Has been given. However, there is a limit to the corrosion resistance of these steel pipe piles, and the life is said to be 15 to 20 years in the case of painting and 40 years in the case of heavy corrosion prevention.
On the other hand, in order to enhance the corrosion resistance of anticorrosion steel pipe piles, it has been proposed to manufacture the pile body from a clad steel of stainless steel or a corrosion resistant material such as stainless steel and ordinary steel, but such piles have high initial costs, It is a disadvantage.

In order to eliminate such disadvantages, Japanese Patent Laid-Open No. Hei 2
No. 256713 discloses a steel pipe pile that has been subjected to anticorrosion treatment. That is, the outer surface of the steel pipe pile is given a normal coating base, coated with an adhesive resin having corrosion resistance and elasticity on it, and further coated with a corrosion-resistant metal thin plate processed with embossed unevenness, specifically tightening. While being wound, the anticorrosion steel pipe pile in which the thin plate end portion is folded or caulked and fastened is disclosed, but in such a steel pipe pile,
It is necessary to prepare a corrosion-resistant metal thin plate having a width and a length corresponding to the pipe diameter and the coating length of the steel pipe pile to be coated,
Therefore, productivity is not high. Further, when coating a large diameter and long band, a joint portion is formed in the circumferential direction of the steel pipe of the corrosion-resistant metal thin plate to be coated, which makes efficient coating difficult.

On the other hand, Japanese Utility Model Laid-Open Publication No. 62-44948 discloses a method of anticorrosion construction using a titanium plate having excellent corrosion resistance as a thin metal plate to be coated. That is, as shown in FIG. 6, a sheet-shaped titanium cover main body 30 having a desired width and length and flanges 31 and 31 are formed at both ends thereof, and an insulating material 32 is interposed between the flanges 31 and 31 facing each other. There has been proposed an anticorrosion cover for an existing pile, which is mounted and in which an insulating flange 33 is brought into contact with the flange and is detachably fixed by a corrosion-resistant metal bolt 34. Due to the screw structure, installation of the cover of the existing steel pipe pile requires installation in the sea and requires installation by a diver, which has the disadvantage of extremely high installation cost.

[0005]

DISCLOSURE OF THE INVENTION The present invention is to improve the anticorrosion structure in the steel pipe pile using the conventional titanium plate as described above, and coats the steel pipe pile in the splash / tidal zone in seawater. An object of the present invention is to provide a method for manufacturing an anticorrosion steel pipe pile, which simply and surely fixes a titanium pipe to the steel pipe pile.

[0006]

In order to achieve the above object, the present invention is to weld a retainer made of titanium clad steel to the outer periphery of the lower part of the steel pipe pile in a zone covering the splash / tidal zone of the steel pipe pile. A titanium sheath tube having an inner diameter substantially the same as that of the retainer covering at least the zone is fitted, and a part of the retainer is fitted and joined to the end portion of the titanium sheath tube and the steel pipe pile. A method for producing a metal-coated anticorrosion steel pipe pile, characterized in that a gap is filled with an anticorrosion material. The anticorrosive material to be filled in the gap between the titanium sheath tube and the steel pipe pile can be injected from one or a plurality of filling holes provided at appropriate locations in the steel pipe pile. Further, since the titanium sheath pipe is formed by the spiral method, it is easy to correspond to the diameter and the covering length of the steel pipe pile.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
In the present invention, the retainer fixed to the steel pipe pile is made of a clad material composed of carbon steel or alloy steel on the inside and titanium on the outside, and is fixed to the outer periphery of the steel pipe pile at a predetermined position by winding welding. The retainer is configured in this manner because the steel pipe is joined to the steel pipe pile in the same manner, and welding can be easily performed.

The titanium sheath tube is preferably formed in a spiral shape so that a steel pipe pile is fitted thereinto and has a diameter corresponding to the diameter of the pile, and the titanium sheath pipe is constructed to have a length capable of covering the splash / tidal zone. The sheath tube in which the steel pipe pile is inserted is fitted with a part of the outer periphery of the retainer at its end, and both are joined by welding. The sheath tube and the surface layer of the retainer can be welded to each other with titanium, and it is possible to suppress defects such as poor welding as seen in welding with different metals.

A gap having a thickness equal to the thickness of the retainer is formed between the steel pipe pile and the titanium sheath pipe, and the anticorrosive filler can be injected into this gap through a filling hole previously drilled in the steel pipe pile. The filling of the anticorrosive material is not limited to this, and an appropriate method such as pouring from above the gap can be adopted.

The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 shows an example of a method for producing a sheath pipe from a titanium thin plate having high corrosion resistance. The titanium strip 1 is rotated while being wound in a spiral shape, and its joint (weight) is rotated by an upper roller. The electrode 2 and the lower roller electrode 4 supported by the boom welder 3 are joined by resistance seam welding to manufacture a spiral titanium sheath tube 5. In the figure, 6 is a roller that guides the boom welder 3 and holds the tip pressure of the electrode 4, and 7 is a spiral winding roll.

The sheath tube is generally formed in a spiral shape when the diameter of the steel pipe pile covering the sheath pipe is 800 mmφ or more, and the width of the titanium strip is about 1000 to 1200 mm due to the manufacturing equipment. Since there are many things, the strip width length is insufficient to wind the titanium strip in the width direction and cover the steel pipe pile. Therefore, a plurality of titanium strips are processed and joined in the length direction 39 (Fig. 7 (a)), or a joint 39 in the width direction (see FIG. 7 (b)).
Reference) and adapt it to the circumferential direction of the steel pipe pile,
This is because it takes a considerable amount of work, and it is difficult to smoothly join (butt weld) the edge portions 40, 40 'of the titanium strip when covering the steel pipe pile. That is, the spiral tube manufacturing process does not go through such complicated steps, is simple in process, and is a preferable method, but the present invention is not limited to this, and the scope of achieving the object of the present invention And the method described above under. The titanium strip forming the sheath tube may be commercially pure titanium, and it is sufficient that the plate thickness is about 0.3 to 2 mm.

FIG. 2 shows a steel pipe pile 8 before fitting a titanium sheath pipe.
The retainer 9 is joined to the outer peripheral surface of the lower position of the splash / tidal zone. The retainer 9 is a clad material in which steel (Fe) 10 and titanium 11 are integrated as shown in the bb section in FIG.
Is arranged on the outer circumference, and the inner steel 10 and the steel pipe pile 8 are TIG-welded and fixed to the steel pipe pile in a headband shape. The joining of this part is steel to steel, and a weld having stable joining characteristics is obtained. The retainer 9 may be installed at one place below the steel pipe pile, but the thickness thereof is not particularly limited, but if the retainer 9 is too thick, the fixing of the sheath pipe becomes unstable and a large amount of filler is required. Is disadvantageous from doing so,
It is preferably about 1 to 6 mm. The plate thickness of titanium is 1 mm or less.

FIG. 3 is a sectional view showing a state where the titanium sheath pipe 5 is fitted to the steel pipe pile 8. The titanium sheath tube 5 has its end 5'fitted into a part of the retainer 9 (up to a half part in the length direction in the example of the figure) and joined by welding. This welding also serves as a titanium-titanium joint, which enables stable high-speed joining. A gap equivalent to the thickness of the retainer 9 is formed between the steel pipe pile 8 and the titanium sheath pipe 5, and the gap is filled with a filler. As the filler 12, a seawater-resistant insulating material is preferable, and epoxy resin, polymer resin, fluorine resin, mortar, adhesive rubber or the like can be used. Irradiation of infrared rays or ultraviolet rays to the resin is blocked by the sheath tube, deterioration of the resin is prevented, and the corrosion-resistant life of the resin is extended in combination with titanium, which has excellent corrosion resistance. The resin or the like may be applied to the surface of the steel pipe pile in advance, but this may hinder the insertion of the sheath pipe. Therefore, when applying it in advance, it is necessary to make it thin.

FIG. 4 shows another embodiment of the present invention, in which a retainer 9 is fixed to the outer peripheral surface of the steel pipe pile 8 at the lower position of the splash / tidal zone, and the titanium sheath pipe 5 is fitted and fixed to the retainer 9. 3 is the same as that of FIG. 3, and further, ribs 13 are provided on the outer peripheral surface of the steel pipe pile 8 covered with the titanium sheath pipe 5 at appropriate intervals in the circumferential direction or the length direction of the pile 8. To do.
It is not necessary to use a special material for the ribs 13, that is, ordinary mild steel may be used, and the ribs 13 are formed at a height so as to contact the inner circumference of the sheath tube 5. Since the length of the sheath tube 5 may be 10 to 12 m, the ribs provide a role as a spacer with the sheath tube and a reinforcing effect, and the injection amount of the filler can be saved.

An injection hole 14 is provided at an appropriate position in the steel pipe pile 8 and a filler 12 is press-fitted into the gap between the titanium sheath pipe and the inside of the pit by a nozzle 15. Further, by providing the air vent holes 16 (see FIG. 3) at appropriate places of the steel pipe pile 8, it is convenient to press fit the filler. At this time, when the ribs 13 are installed, it is preferable to provide the passages 13 'at appropriate positions so that the filler can advance.

[0016]

EXAMPLE Using a titanium strip having a thickness of 0.4 mm and a width of 1000 mm, a diameter of 810 mmφ was obtained by lap resistance welding shown in FIG.
The spiral sheath tube was manufactured. A retainer made of clad steel formed of a 4 mm mild steel plate and a 1 mm titanium plate is fixed to the outer periphery of a steel pipe pile having a diameter of 800 mmφ by TIG welding with the steel portion of the retainer, and the titanium sheath pipe is shown in FIG. Is attached to the steel pipe pile and is tied to the titanium surface of the retainer.
It was fixed by the G welding method. After that, polyurethane resin was press-fitted through the filling hole provided in the steel pipe pile, and it was possible to smoothly fill the gap between the steel pipe pile and the titanium sheath pipe without forming bubbles.

Since the lap resistance welding used for the production of the sheath pipe is a direct continuous welding, no defects such as seams are generated.
Welding with good airtightness is possible. Further, when welding the sheath tube and the titanium surface of the retainer, it was possible to obtain a good joint by eliminating the gap between the overlapping portions and improving the adhesion. In the PT inspection and the airtightness test after welding, there were no defects, cracks, air leaks, etc., which were good.

[0018]

As described above, in the steel pipe pile of the present invention, the titanium sheath pipe excellent in corrosion resistance can be reliably and easily fixed and coated in the splash and tidal band in seawater, and the steel pipe pile and the titanium sheath can be covered. It is possible to provide the necessary filler in the gaps between the pipes and provide a corrosion-resistant steel pipe pile having long-life corrosion resistance.

[Brief description of the drawings]

FIG. 1 (a) is a diagram showing an example of a method for producing a sheath tube from a titanium thin plate of the present invention, and FIG. 1 (b) is a side view thereof.

FIG. 2 (a) shows a steel pipe pile before fitting the titanium sheath pipe of the present invention, and FIG. 2 (b) is a sectional view taken along line bb.

FIG. 3 is a sectional view showing a state in which a titanium sheath pipe is fitted to the steel pipe pile of the present invention.

FIG. 4 shows another embodiment of the present invention, partly in section.

FIG. 5 is a diagram showing a conventional anticorrosion construction method using a titanium plate.

6 (a) and 6 (b) are views for explaining the formation state of a titanium sheath tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Titanium strip 2 ... Upper roller electrode 3 ... Boom welder 4 ... Lower roller electrode 5 ... Spiral titanium sheath tube 6 ... Tip pressure holding roller 7 ... Spiral winding roll 8 ... Steel pipe pile 9 ... Retainer 10 ... Steel 11 ... Titanium 12 ... filling material 13 ... passage 14 ... filling hole 15 ... nozzle 16 ... air vent hole

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadami Adachi 3-5-4 Tsukiji, Chuo-ku, Tokyo Inside Nittetsu Welding Industry Co., Ltd. (72) Shinji Fukano 3-5 Tsukiji, Chuo-ku, Tokyo No. Nippon Steel Welding Industry Co., Ltd. (72) Inventor Kazumi Matsuoka 20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel Co., Ltd.Technology Development Division (72) Inventor Nobuhiro Goto 20-1 Shintomi, Futtsu-shi, Chiba New Nippon Steel Co., Ltd. Technology Development Division (72) Inventor Hisashi Kanai 2-6-3 Otemachi, Chiyoda-ku, Tokyo Inside Nippon Steel Co., Ltd. (72) Masayoshi Akasaka 2-6 Otemachi, Chiyoda-ku, Tokyo -3 Nippon Steel Co., Ltd. (72) Inventor Yasuo Takahashi 2-6 Otemachi, Chiyoda-ku, Tokyo 2-6-3 Nippon Steel Co., Ltd. (72) Inventor Kazuhiro Kinoshita Univ. Of Chiyoda-ku, Tokyo Town 2-6-3 Nippon Steel Co., Ltd. in

Claims (3)

[Claims] 1. A retainer made of titanium clad steel is welded to the outer periphery of the lower portion of a zone covering a splash / tidal zone of a steel pipe pile, and the steel pipe pile has an inner diameter substantially equal to that of the retainer covering at least the zone. A metal coating characterized by fitting a titanium sheath tube having a groove and fitting and joining a part of a retainer to the end of the titanium sheath tube, and filling the gap between the formed titanium sheath tube and the steel pipe pile with food-proof material. Manufacturing method of anti-corrosion steel pipe pile. 2. A retainer made of titanium clad steel is welded to the outer periphery of the lower portion of the zone covering the splash / tidal zone of the steel pipe pile, and the steel pipe pile has an inner diameter substantially the same as that of the retainer covering at least the zone. With a titanium sheath pipe having a fitting, a part of the retainer is fitted and joined to the end of the titanium sheath pipe. A method for producing a metal-coated anticorrosion steel pipe pile, characterized by pouring and filling. 3. The method for producing a metal-coated anticorrosion steel pipe pile according to claim 1, wherein the titanium sheath pipe is formed by a spiral method.