JP2022121577A - Corrugated steel water channel member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a corrugated steel water channel member capable of reducing life cycle cost and improving corrosion resistance, which are two basically needed characteristics, and reducing the plate thickness when used for a water channel.

SOLUTION: This corrugated steel water channel member is used for forming a water channel and is made of a corrugated steel material having a section corrugated in the channel direction of the water channel. The corrugated steel material is stainless steel having no Mo added thereto and containing Mo as an inevitable impurity.

SELECTED DRAWING: Figure 6

COPYRIGHT: (C)2022,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a corrugated steel water channel member that uses steel to construct a water channel.

Concrete construction is generally used for the construction of waterways. However, in recent years, there are cases where a channel is constructed by connecting steel channel members that are easy to construct. Especially when waterways are constructed on soft ground, steel waterway members are often used because they are lightweight and strong.

In a water channel member made of steel plate, the steel material corrodes quickly when water constantly flows or accumulates in the water channel. For this reason, hot-dip galvanized plated steel sheets are used for steel water channel members (see, for example, Patent Document 1).

JP-A-2002-121731

When the waterway is constructed with concrete, construction takes time and effort. In addition, even after construction, it is necessary for the manager to periodically repair joints or cracks to maintain and manage them.

On the other hand, when the water channel is constructed with a steel plate water channel member using a plated steel plate, the plating delays the corrosion of the steel material, and the effect of extending the life of the steel water channel member is obtained. However, after all the plating on the plated steel sheet has been dissolved, it is necessary for the manager to maintain and manage the corrosion while repairing the corrosion of the steel material. Alternatively, it is necessary to replace the water channel member made of steel plate using plated steel plate with a new one. As described above, maintenance and management costs or new replacement costs are required, and the life cycle cost of corrugated steel water channel members is high.
In addition, when the channel is constructed with a steel channel member using a plated steel plate, the corrosion resistance is low.
In addition, when the channel is constructed with a steel channel member using a plated steel plate, the plate thickness is thick in consideration of the influence of water pressure.

The present invention is intended to solve the above problems, and can reduce the life cycle cost and improve corrosion resistance, which are two fundamentally required characteristics, and reduce the plate thickness when used in waterways. An object of the present invention is to obtain a corrugated steel water channel member capable of reducing the cost.

The corrugated steel water channel member of the present invention is used to form a water channel, and is made of a corrugated steel material having a corrugated cross section along the flow path direction of the water channel. , the corrugated steel material is stainless steel to which Mo is not added and Mo, which is an unavoidable impurity, is contained.

According to the corrugated steel water channel member according to the present invention, the corrugating steel material is stainless steel. Therefore, it is possible to reduce the life cycle cost and improve the corrosion resistance, which are two fundamentally required properties, and to reduce the plate thickness when used in water channels.

1 is a perspective view showing a construction state of a corrugated steel water channel member according to Embodiment 1 of the present invention; FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a schematic configuration of a corrugated steel water channel member according to Embodiment 1 of the present invention in a construction state; BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing a schematic configuration of a corrugated steel water channel member according to Embodiment 1 of the present invention; BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing a schematic configuration of a corrugated steel water channel member having a welded portion according to Embodiment 1 of the present invention; BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing a schematic configuration of a corrugated steel channel member for corner portions according to Embodiment 1 of the present invention; FIG. 2 is a diagram showing an example and a comparative example of the corrugated steel water channel member according to Embodiment 1 of the present invention;

An embodiment of a corrugated steel water channel member according to the present invention will be described below. In addition, the form of drawing is an example and does not limit this invention. In addition, the same reference numerals in each drawing are the same or equivalent, and this is common throughout the specification. Furthermore, in the drawings below, the size relationship of each component may differ from the actual size.

Embodiment 1.
[Construction status of corrugated steel waterway members]
FIG. 1 is a perspective view showing a construction state of a corrugated steel water channel member 1 according to Embodiment 1 of the present invention.
As shown in FIG. 1, the corrugated steel waterway members 1 are connected and buried in the ground at their lower halves to form a waterway. For this reason, the corrugated steel water channel member 1 is installed in an environment where bacterial corrosion is likely to occur because it comes into contact with the soil of the ground, which is a habitat for grasses, insects, and the like.

Waterways are used for agricultural waterways, industrial waterways, or temporary waterways for civil engineering works. The water channel is an open channel with an open top, through which water flows. In addition, fallen leaves or garbage may flow into the waterway. In addition, mud may flow into the waterway.

[Construction of Corrugated Steel Water Channel Member 1]
FIG. 2 is a perspective view showing a schematic configuration of the corrugated steel waterway member 1 according to Embodiment 1 of the present invention in a construction state.
As shown in FIG. 2, the upstream corrugated steel channel member 1 and the downstream corrugated steel channel member 1 are connected. The downstream end portion of the upstream corrugated steel channel member 1 and the upstream end portion of the downstream corrugated steel channel member 1 are overlapped with a sealing material 2 indicated by a thick black line in the figure interposed therebetween. there is The upstream end of the corrugated steel water channel member 1 on the upstream side is overlaid on the upper side of the upstream end of the corrugated steel water channel member 1 on the downstream side. This prevents the mud flowing in the waterway from accumulating at the bottom of the waterway. At the connecting portion, the downstream end of the upstream corrugated steel water channel member 1 and the upstream end of the downstream corrugated steel water channel member 1 are bolted and connected.

In the corrugated steel water channel member 1, a wale 3 is arranged at the upper end edge projecting upward of the side wall portion for reinforcement. The wales 3 are made of L-shaped steel, and are provided on the upper edges of the side walls 1a and 1b of the corrugated steel water channel member 1 along the direction of the flow path. The wale 3 is bolted and fixed to the corrugated steel water channel member 1 .

In the corrugated steel water channel member 1, for reinforcement, struts 4 are bridged by wales fixed to the upper edges projecting upward of the left and right side wall portions 1a and 1b with respect to the flow channel direction. are placed. The struts 4 are made of L-shaped steel, and are provided over the width direction perpendicular to the direction of the flow path on the wales 3 fixed to the upper edges of the left and right side walls 1a and 1b. The struts 4 are fixed to the wale 3 by bolting.

[Configuration Example 1 of Corrugated Steel Water Channel Member 1]
FIG. 3 is a perspective view showing a schematic configuration of the corrugated steel water channel member 1 according to Embodiment 1 of the present invention.
As shown in FIG. 3, the corrugated steel water channel member 1 is made of a corrugated steel material having a corrugated cross section along the flow path direction. A corrugated steel water channel member 1 is formed by curving a corrugated steel material having a corrugated cross section along the flow direction with alternately continuous ridges and troughs in the longitudinal direction, which is the flow direction, into a U-shaped groove. It is what I did.

A corrugated steel water channel member 1 has left and right side wall portions 1a and 1b and a lower bottom wall portion 1c so as to form a U-shaped groove. The corrugated steel water channel member 1 has side walls 1a and 1b erected from a bottom wall 1c at both left and right ends. The bottom wall portion 1c and the side wall portions 1a and 1b are curved and connected to each other with the corner portions formed into an R curve.
The corrugated steel water channel member 1 is formed with bolt holes (not shown) for connection in the upstream end, the downstream end and the upper edge.

The shape of the corrugated steel water channel member 1 is not limited to the U-shaped groove. The corrugated steel water channel member 1 may have any shape as long as it can be formed by bending a corrugated steel material having a corrugated cross section along the flow path direction. All of the bottom wall portion 1c may be formed with an R curve. Further, the corrugated steel water channel member 1 may have flange portions protruding outward from the upper edge portions of both side wall portions 1a and 1b and provided along the direction of the flow passage.

[Configuration Example 2 of Corrugated Steel Water Channel Member 1]
FIG. 4 is a perspective view showing a schematic configuration of a corrugated steel water channel member 1 having welded portions 5 according to Embodiment 1 of the present invention. In addition, in Configuration Example 2 of the corrugated steel plate waterway member 1, description of the same configuration as in Configuration Example 1 of the corrugated steel plate waterway member 1 described above will be omitted, and only characteristic portions will be described.

As shown in FIG. 4, the corrugated steel channel member 1 is provided with a water depth gauge 6 inside the side wall portion 1a for detecting the water depth of the water flowing through the channel. For this reason, the corrugated steel water channel member 1 has a welded portion 5 in the illustrated black region as a mounting portion for mounting the water depth gauge 6 .
As the water channel member 1 made of corrugated steel plate to which the water depth gauge 6 is attached, the water channel member 1 made of corrugated steel plate for a straight portion shown in FIG. 3 is taken as an example.
Moreover, the attachment article attached by the welding part 5 is not restricted to a water depth gauge. The attached article may be, for example, instruments such as a water temperature gauge and a thermometer, a water level monitoring camera, a surrounding monitoring camera, an information communication terminal, or a combination of these devices.

The welding part 5 uses, for example, TIG butt welding. In TIG butt welding, the base metals are butted together and an arc is generated between the non-consumable electrode and the base metal. In TIG butt welding, this arc is used as a heat source to melt the filler rod and the base metal, and an inert gas is flowed around the melted portion. This allows TIG butt welding to weld while shielding the weld from ambient air.

Welding to the welded portion 5 is not limited to TIG butt welding. For example, shielded arc welding, TIG welding, MIG welding, MAG welding, etc. may be used.

[Configuration Example 3 of Corrugated Steel Water Channel Member 1]
FIG. 5 is a perspective view showing a schematic configuration of a corrugated steel channel member 1 for corner portions according to Embodiment 1 of the present invention. In configuration example 3 of corrugated steel plate waterway member 1, description of configurations similar to configuration examples 1 and 2 of corrugated steel plate waterway member 1 described above will be omitted, and only characteristic portions will be described.

The corrugated steel water channel member 1 shown in FIG. 5 is for corner portions. A corrugated steel channel member 1 for a corner portion has an upstream part 1d and a downstream part 1e. The corrugated steel water channel member 1 for the corner portion has a welded portion 5 that is welded so as to connect the upstream part 1d and the downstream part 1e. In other words, the welded portion 5 that connects the upstream part 1d and the downstream part 1e is long in the flow path direction of the corrugated steel water channel member 1 over both side wall portions 1a and 1b and the bottom wall portion 1c to both upper ends. It has a welded weld area.

In the upstream side part 1d, in the state of the corrugated steel water channel member 1 for the straight part shown in FIG. In addition, in the downstream part 1e, in the state of the corrugated steel water channel member 1 for the straight part shown in FIG.
The upstream part 1d is cut along the scored lines, and the cut surface is sanded to smooth the surface. Further, the downstream part 1e is cut along the scored lines, and the cut surface is sanded to smooth the surface.
Then, the upstream part 1d and the downstream part 1e are finely adjusted by hammering or the like in order to match the wave shape of the steel plate while connecting the upstream part 1d and the downstream part 1e. Thereafter, the cut surfaces of the upstream part 1d and the downstream part 1e are temporarily fixed by temporary welding, and the temporarily fixed cut surfaces are connected by final welding, which is TIG butt welding.

[Component Composition of Corrugated Steel Water Channel Member 1]
The steel material of the corrugated steel water channel member 1 is stainless steel. Moreover, the steel material is preferably ferritic stainless steel among stainless steels. In particular, the steel material is most preferably SUS443J1 (JIS standard) among ferritic stainless steels.

Here, SUS443J1 is mass%, C: 0.03% or less, Si: 1.0% or less, Mn: 0.5% or less, P: 0.04% or less, S: 0.02% or less , Al: 0.1% or less, Cr: 20.5% or more and 22.5% or less, Cu: 0.3% or more and 0.8% or less, Ni: 1.0% or less, Ti: 4 × ( C% + N%) or more, 0.35% or less, Nb: 0.01% or less, N: 0.03% or less, C + N: 0.05% or less, and the balance consists of Fe and unavoidable impurities, It satisfies the following formula (1).
[Formula (1)] 240 + 35 x (Cr% - 20.5) + 280 x {Ti% - 4 x (C% + N%)} ≥ 280
Here, C%, N%, Cr%, and Ti% represent the contents (mass%) of C, N, Cr, and Ti, respectively.

[Comparison between Examples and Comparative Examples]
FIG. 6 shows an example and a comparative example of the corrugated steel water channel member 1 according to Embodiment 1 of the present invention.
The present inventors have investigated Examples 1-3 in which the steel material of the corrugated steel water channel member 1 is SUS443J1, Example 4 in which the steel material contains other stainless steel, Example 5 in which it is SUS430, and Example 6 in which it is SUS304. Verification was performed by comparing the example of the present invention with Comparative Examples 1-3.
Example 1-3 is a steel material satisfying the composition of SUS443J1.
In Example 4, the steel material is stainless steel other than SUS443J1. In Example 5, the steel material is SUS430. In Example 6, the steel material is SUS304. In Comparative Example 1, the steel material is galvanized steel plate HDZ45. In Comparative Example 2, the steel material is galvanized steel plate HDZ55. In Comparative Example 3, the steel material is a hot-rolled steel sheet.

In FIG. 6, the criteria for each test and verification are as follows.

(1) Salt spray test on flat plate material: A test piece of 2 mm × 70 mm × 150 mm conforms to JIS K 5600-7-1, and 5% NaCl is sprayed in a tank at 35 ° C. A test was performed for 5000 hours. rice field. ◎ (acceptable) if the area rate of red rust after the test is less than 10%, ○ (acceptable) if it is 10% or more and less than 30%, △ (unsuitable) if it is 30% or more and less than 50%, and 50% or more When there was, it determined with x (failure).

(2) Salt spray cycle test on welded material with welded portion: Two specimens of 2 mm x 35 mm x 150 mm were TIG welded in the longitudinal direction. After polishing the surface of the weld with #600, it was subjected to the test. A cycle of spraying 5% NaCl for 2 hours (35° C.)→drying (60° C., RH 30%) for 4 hours→wetting (50° C., RH 95%) for 2 hours was tested for 30 cycles. ◎ (accepted) when the area ratio of red rust generation in the weld is less than 10%, ○ (acceptable) when it is 10% or more and less than 30%, △ (unsuitable) when it is 30% or more and less than 50%, 50% It was determined to be x (failure) when it was more than that.

(3) Magnetism: A normal ferrite magnet of 15 mm in diameter was placed close to the sample, and the sample was evaluated as ◯ (acceptable) if it had an attractive force, and as x (failed) if it did not have an attractive force.

(4) Initial introduction cost: If the purchase cost is equal to or less than the conventional galvanized steel plate HDZ45, ⊚ (acceptable); It was judged to be Δ (unsuitable) when it was more than 75 times and 3 times or less, and to be x (fail) when it was more than 3 times.

(5) Life cycle cost (LCC): The total cost for a general period of 40 years, including the initial cost of installation, repair, maintenance and management costs until renewal, is 1/3 that of the conventional galvanized steel plate HDZ45. If less than ◎ (accepted), more than 1/3 and less than 0.8 times ○ (acceptable), more than 0.8 times and less than 1 times △ (unsuitable), 1 times or more × ( failed).

As shown in FIG. 6, in Examples 1 to 3 of the present invention, the corrugated steel waterway member 1 has a low initial introduction cost, improved corrosion resistance in outdoor exposure, and partial corrosion under water exposure. An improvement in corrosion resistance was observed in the weld 5 that was performed. Due to these effects, the life cycle cost of the corrugated steel water channel member 1, which is two characteristics that are basically required as a synergistic effect, can be significantly reduced, and the long-term durability is remarkably excellent. Therefore, it can be seen that all the characteristics required for future waterway facilities can be improved.

[Effect of Embodiment 1]
According to Embodiment 1, the corrugated steel water channel member 1 uses a corrugated steel material having a corrugated cross section along the direction of the flow path. The corrugated steel material is stainless steel.
According to this configuration, since the corrugated steel material of the corrugated steel channel member 1 is stainless steel, the service life of the corrugated steel channel member 1 can be significantly extended. In addition, the corrugated steel water channel member 1 can greatly reduce the maintenance and management by repairing, which is essential for conventional water channel members or concrete water channel structures. As a result, the life cycle cost of the corrugated steel water channel member 1 can be reduced.
Further, since the corrugated steel material of the corrugated steel water channel member 1 is stainless steel, the corrosion resistance can be improved as proved by the test of the flat plate material.
Therefore, it is possible to reduce the life cycle cost and improve the corrosion resistance, which are two fundamentally required properties.
In addition, since the corrugated steel material of the corrugated steel water channel member 1 is stainless steel, the strength of the material is improved, and when used in a water channel where water pressure is applied, the plate thickness can be reduced compared to a plated steel plate. In addition, the weight of the corrugated steel channel member 1 can be dramatically reduced compared to a concrete channel structure or the like. As a result, the water channel member 1 made of corrugated steel sheet having a reduced weight can be improved in workability on soft ground, and transportation cost and handling property can also be improved.

According to Embodiment 1, the corrugated steel material is ferritic stainless steel among stainless steels.
According to this configuration, since the corrugated steel material is ferritic stainless steel, the corrugated steel water channel member 1 has magnetism. Therefore, the corrugated steel water channel member 1 can be moved or installed by being attracted by the action of magnetic force using an electromagnet heavy machine such as a lifting magnet work vehicle. As a result, it is possible to improve the handling of the work for installing the corrugated steel water channel member 1 in the water channel. Therefore, as the number of young workers will decrease in the future, even if the number of workers is small, and the workers are elderly or female, the construction work of the corrugated steel water channel member 1 can be easily performed. Matching properties are obtained.
In addition, when the corrugated steel water channel member 1 is discarded mixed with concrete or resin members due to large-scale repair of water channels, etc., the corrugated steel water channel member 1 having magnetism is used as a separator using an electromagnet or the like. It can be easily separated by attracting by the action of magnetic force. As a result, the corrugated steel water channel member 1 can be recycled after being separated from other items, and characteristics suitable for environmental friendliness (separate waste recycling) can be obtained.

According to Embodiment 1, the corrugated steel material is SUS443J1 among ferritic stainless steels.
According to this configuration, since the corrugated steel material is SUS443J1, expensive Mo or the like is not added, the price of the material is stable, and the initial introduction cost is relatively low. In addition, the corrugated steel water channel member 1 is excellent in corrosion resistance in outdoor exposure. In addition, the corrugated steel water channel member 1 is excellent in corrosion resistance at the welded portion 5 where it is partially performed. As a result, due to the low initial introduction cost of the corrugated steel water channel member 1, the improvement of the corrosion resistance in outdoor exposure, and the improvement of the corrosion resistance at the welded portion 5, two characteristics that are basically required as a synergistic effect. The life cycle cost of the molded steel water channel member 1 can be significantly reduced, and the long-term durability is remarkably excellent. Therefore, all the characteristics required for future waterway installations can be improved.

According to Embodiment 1, the corrugated steel water channel member 1 has the welded portion 5 for attaching the attachment article.
According to this configuration, the corrugated steel water channel member 1 has a welded portion 5 which is welded to an attachment portion for attaching an attachment article such as a water depth gauge. Here, in the case of a plated steel sheet, the welded portion is in a thin plated state and tends to be easily corroded. In addition, when the steel material is stainless steel such as SUS430, Cr carbide is generated in the welded portion heated to 600° C. to 800° C. during welding, and a depleted layer with a Cr content of less than 12% is generated, resulting in stress. Sensitization occurs that increases the susceptibility to corrosion cracking. For this reason, a sensitized welded portion tends to have lower durability than a non-welded portion. On the other hand, when the corrugated steel material is SUS443J1, the corrugated steel waterway member 1 contains Ti as a component of SUS443J1, so a depleted layer having a Cr content of less than 12% is unlikely to occur even during welding, and the welded portion 5 sensitization can be suppressed. As a result, the corrugated steel water channel member 1 has excellent corrosion resistance at the welded portions 5 and excellent long-term durability.

According to Embodiment 1, the corrugated steel water channel member 1 is for corner portions. The corrugated steel water channel member 1 has an upstream part 1d and a downstream part 1e. The corrugated steel water channel member 1 has a welded portion 5 that connects the upstream part 1d and the downstream part 1e.
According to this configuration, the welded portion 5 that connects the upstream part 1d and the downstream part 1e extends over both side wall portions 1a and 1b and the bottom wall portion 1c in the flow path direction of the corrugated steel water channel member 1. It has a welded area that is long welded to the top edge. The welded portion 5 that connects the upstream part 1d and the downstream part 1e is a part that is easily corroded under water exposure in direct contact with water flowing through the corrugated steel channel member 1 for the corner portion. On the other hand, since the corrugated steel water channel member 1 for the corner portion contains Ti as a component of SUS443J1, it is possible to suppress the sensitization of the welded portion 5 connecting the upstream part 1d and the downstream part 1e. Therefore, the corrugated steel water channel member 1 for the corner portion having a long weld region as the weld portion 5 has excellent corrosion resistance at the weld portion 5 exposed to water, excellent long-term durability, and the corrugated steel plate for the corner portion. The life cycle cost of the canal member 1 can be further reduced.

It should be noted that the embodiments disclosed this time should be considered as examples in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the meaning and range of equivalents of the scope of the claims.

1 Corrugated Steel Water Channel Member 1a Side Wall Part 1b Side Wall Part 1c Bottom Wall Part 1d Upstream Part 1e Downstream Part 2 Seal Material 3 Wing 4 Strut 5 Welding Part 6 Water Depth Total.

Claims (5)

A corrugated steel water channel member made of a corrugated steel material that is used to form a water channel and has a corrugated cross section along the flow path direction of the water channel,
The corrugated steel material is a corrugated steel water channel member, which is stainless steel to which Mo is not added and Mo which is an unavoidable impurity is contained. 2. The corrugated steel water channel member according to claim 1, wherein said corrugated steel material has no welded portion on its surface. The corrugated steel water channel member according to claim 1 or 2, wherein the corrugated steel material is stainless containing 8.01 (mass%) or less of Ni. The corrugated steel members arranged along the flow direction of the water channel are sealed so that the downstream end of the upstream corrugated steel member is above the upstream end of the downstream corrugated steel member. The corrugated steel waterway member according to any one of claims 1 to 3, wherein the waterway member is stacked with a material interposed to form the waterway. The corrugated steel has, in terms of mass %, Al: 0.1% or less, Cr: 20.5% or more and 22.5% or less, Cu: 0.3% or more and 0.8% or less, Ni: 1.0% or less, Ti: 4 × (C % + N%) or more, 0.35% or less, Nb: 0.01% or less, N: 0.03% or less, C + N: 0.05% or less, and the balance is Fe and unavoidable impurities. can be,
[Formula (1)] 240 + 35 x (Cr% - 20.5) + 280 x {Ti% - 4 x (C% + N%)} ≥ 280
The corrugated steel water channel member according to any one of claims 1 to 4, which has a configuration satisfying

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