JPH07314188A - One side submerged arc welding method - Google Patents

Abstract

PURPOSE:To eliminate the drawback in the case of mounting a backing strip by a tacky adhesive tape, i.e., the problem that a tacky adhesive remains on the rear surfaces of steel sheets after this backing strip is removed after welding, to facilitate mounting and to assure defectless penetration beads. CONSTITUTION:The backing strip 3 is adhered to the rear surfaces of the steel sheets 1 by a tacky adhesive tape 4 from the rear side of the backing strip 3 in one side submerged arc welding. A tacky adhesive tape which is >=300gf/10mm width in tacky adhesive power to peeling (JISZ0237) at ordinary temp. (23 deg.C) is used for the above tacky adhesive tape 4. The position where the tacky adhesive tape 4 is adhered to the steel sheets 1 is set at a position apart by >=80mm from a groove line 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-sided submerged arc welding method in which a backing material is attached to the rear surface of a plate to be welded and single-sided submerged arc welding is performed from the front surface side of the plate to be welded. The present invention relates to a single-sided submerged arc welding method in which this material is attached to the groove line position on the back surface of the plate to be welded with an adhesive tape and is welded from the front side of the plate to be welded to form a back bead.

[0002]

2. Description of the Related Art In a single-sided submerged arc welding method for a steel sheet using a simple backing material, the backing material is attached to the groove position on the back surface of the steel sheet to be welded. Generally, this backing material is attached to the back surface of the steel sheet. As a method of closely contacting, conventionally, after applying a backing plate to the back side of the backing material with an aluminum plate or the like,
A method of pushing up an aluminum plate with a magnet or a wedge to bring the backing material into close contact with the back surface of the steel plate has been widely adopted.

However, in the case of a joint having a long welding length and a joint having insufficient space for performing work, it is necessary to carry a heavy magnet or wedge and a jig for attachment to a welding position, attach and remove them. It was a considerable burden and was a factor that reduced the efficiency of welding work. In addition, a heavy magnet may come off and drop during welding, which is a serious safety problem.

In order to solve such a problem, the applicant of the present application has developed a method for attaching a backing material by using an adhesive tape which is easy to attach and remove and is lightweight, and has already applied for it (special feature: Kaihei 5-161975). As this adhesive tape, one having a predetermined adhesive force even at high temperature is used. When the backing material is attached with this adhesive tape, the adhesion of the backing material is good even in high heat input submerged arc welding, and a sound back bead can be secured.

[0005]

However, when the backing material is attached to the back surface of the steel sheet using this adhesive tape, when the backing material is removed after welding, the adhesive remains on the back surface of the steel sheet and adheres to it. There is a problem that a great deal of time is wasted in the work of removing the adhesive.

The present invention has been made in view of the above problems, and has a drawback in that the backing material is attached with an adhesive tape, that is, the adhesive remains on the back surface of the steel plate after the backing material is removed after welding. The problem is that it is easy to install, a sound back bead can be secured, there is no need to remove the adhesive remaining on the back of the steel plate, and the backing material can be installed and removed with high efficiency. An object is to provide a submerged arc welding method.

[0007]

A single-sided submerged arc welding method according to the present invention is a single-sided submerged arc welding in which a backing material is attached to the backside of a plate to be welded with an adhesive tape and one-sided submerged arc welding is performed on the front side of the plate to be welded. In the arc welding method, the adhesive tape having a peeling adhesive strength (JIS Z0237) of 300 gf / 10 mm width or more at room temperature (23 ° C.) is used, and the adhesive position of the adhesive tape to the plate to be welded is a groove line. It is characterized in that it is located at a distance of 80 mm or more from.

Further, another one-sided submerged arc welding method according to the present invention is characterized in that a pressing jig is applied to the back surface of the backing material and is adhered to the plate to be welded with the adhesive tape. This adhesive tape has a peeling adhesive strength (JIS Z0237) of 300 gf / 1 at room temperature (23 ° C.).
A tape having a width of 0 mm or more is used, and the adhesive tape is bonded to the plate to be welded at a position separated by 80 mm or more from the groove line.

[0009]

The present inventors repeated various experimental studies to develop a method capable of preventing the adhesive from remaining after welding and simplifying the attachment and removal of the backing material. I found it.

That is, in the conventional method of attaching the backing material using the adhesive tape, the backing material having a width of about 30 to 60 mm is generally arranged on the back surface of the steel plate and covered with the backing material back surface and backing material. The backing material was attached to the back surface of the steel plate by adhering an adhesive tape to the back surface of the steel plate in the uncovered portion. Therefore, since the adhesive portion of the adhesive tape on the back surface of the steel sheet is close to the welding line, the temperature of the adhesive portion becomes high after the arc passes. As described above, when the temperature of the bonded portion becomes high, the viscosity of the ordinary organic pressure-sensitive adhesive decreases, and the organic pressure-sensitive adhesive is well adapted to the steel plate. For this reason, after the welding is completed and the temperature of the steel sheet has dropped to some extent, when the adhesive tape is tried to be peeled off, the adhesive tape adheres to the back surface of the steel sheet with the adhesive being fitted to the back surface of the steel sheet. It remains on the back of the steel plate. Since the adhesive remaining on the back surface of the steel plate impairs the paintability, it needs to be removed, and this removing operation requires an extremely large amount of time, which significantly impairs the welding workability.

Based on these facts, the inventors of the present invention have conducted various studies in order to develop a method for avoiding the remaining of the pressure-sensitive adhesive, and as a result, have adhered the pressure-sensitive adhesive tape near the groove line where the temperature of the back surface of the steel sheet is high. And the backside temperature of the steel plate is 150 ° C or less, that is, at a position 80 mm or more away from the groove line, at room temperature (2
Peeling adhesion at 3 ° C (JIS Z0237)
When adhesive tape with a width of 300 gf / 10 mm or more is adhered, the temperature of the steel plate at the adhesion position of this adhesive tape is small, the backing material adheres well during welding, and a sound back bead is obtained. It was found that when the backing material was removed, no adhesive remained on the back surface of the steel sheet, and the work of removing the residual adhesive was unnecessary. The present invention has been made from this point of view.

In addition, in order to adhere an adhesive tape at a position (80 mm or more) away from the groove line and to secure sufficient adhesion of the backside of the steel plate of the backing material, a lightweight pushing jig is backed. It is also possible to arrange it on the back surface of the material and bond this pressing jig to the back surface of the steel plate with an adhesive tape.

[0013]

Embodiments of the present invention will be specifically described below with reference to the accompanying drawings. First, the method of the first embodiment of the present invention will be described with reference to FIG. Figure 1
FIG. 1A is a view showing the back surface of a steel plate, and FIG. 1B is a vertical sectional view thereof. A butt end of a steel plate 1 as a plate to be welded is chamfered obliquely, and the pair of steel plates 1 are butted so that a V-shaped groove is formed on the surface side thereof. Then, on the back surface of the steel plate 1, the backing material 3 is arranged at a position centering on the groove line 2 of the groove portion,
The backing material 3 is attached by being pressed against the back surface of the steel plate 1 with an adhesive tape 4. The adhesive tape 4 has adhesive parts 5 on both sides thereof, and the adhesive tape 5 adheres to the back surface of the steel sheet. Thus, in the present embodiment, all of the adhesive portions 5 are located at a distance of 80 mm or more from the groove line 2.

The adhesive force and the distance from the groove line The adhesive force is specified in JISZ0237, but the peeling adhesive force of the adhesive tape (hereinafter, simply referred to as "adhesive force") is mainly the kind of adhesive and the application. Determined by thickness and temperature. FIG. 2 is a graph showing the relationship between the temperatures of the adhesives A to G and the adhesive force, with the test temperature on the horizontal axis and the adhesive force on the vertical axis. All adhesives have the highest adhesive strength at room temperature, and the adhesive strength decreases as the temperature rises. Also,
Those having a high adhesive strength at room temperature can obtain a relatively high adhesive strength even at a high temperature, but in any case, the adhesive strength is significantly reduced from a temperature exceeding 100 ° C. Therefore, until the back bead is completely formed (the deposited metal is solidified), it is necessary to bond the adhesive tape to a position where the temperature of the back surface of the steel sheet does not rise to 100 ° C. or more and hold the backing material.

The back surface temperature of the steel sheet and the position from the groove line In FIG. 3, the horizontal axis indicates the distance from the groove line 2 and the vertical axis indicates the steel sheet surface temperature at the time of forming the back bead. It is a graph which shows the relationship between the distance from a groove line at the time of welding with various groove shapes about a steel plate, and the steel plate surface temperature at the time of back bead formation. This graph shows that the back bead is considered to be completely formed by performing submerged arc single-sided single-layer welding on three types of steel plates with thicknesses of 16 mm, 19 mm, and 25 mm using a simple backing material. It is a result of measuring the temperature of the back surface of the steel sheet at a position 100 mm behind from. As described above, the temperature at which the adhesive strength of the adhesive tape is stable is 100 ° C. or less. Therefore, in order to maintain the adhesiveness of the backing material until the formation of the back bead, it is judged from this measurement result. Then, it can be seen that it is necessary to adhere the adhesive tape at a position at least 35 mm away from the groove line.

Steel plate backside temperature and residual adhesive The relationship between the maximum temperature of the backside of the steel plate and the presence or absence of the adhesive remaining on the backside of the steel plate when the adhesive tape having the respective adhesive properties shown in FIG. 2 is used . investigated. as a result,
Both adhesive tapes have a maximum backside temperature of 150 ° C.
When the amount was above, the amount of the residual extension agent rapidly increased. Figure 4
Is the distance from the groove line on the horizontal axis and the maximum temperature of the back surface of the steel plate on the vertical axis, and shows the relationship between the distance from the groove line and the maximum temperature on the back surface of the steel plate for various plate thicknesses and groove shapes. It is a graph figure which shows. As is clear from FIG. 4, under any of the conditions, the maximum temperature on the back surface of the steel plate becomes approximately 150 ° C. or lower when the steel plate is separated from the groove line by 80 mm or more.

Good back bead without adhesive remaining on the back of the steel plate
Range figure 5 which is obtained is one that describes the combined data shown in FIGS. As described above, in order to obtain a good back bead, as can be seen from the data in FIG. 3, the temperature of the back surface of the steel sheet at the end of forming the back bead is 100 ° C. or less, that is, 35 from the welding line.
Adhesive tape may be attached at a position separated by at least mm. However, in order to prevent the adhesive from remaining on the back surface of the steel sheet when the adhesive tape is peeled off after welding, the maximum temperature on the back surface of the steel sheet is about 150 ° or less, that is, a position 80 mm or more away from the groove line. It is necessary to glue an adhesive tape on.

Therefore, as shown in FIG. 5, in order to obtain a good back beat and not to leave an adhesive on the back surface of the steel plate when the backing material is removed after the welding is completed, It is necessary to adhere an adhesive tape to a position where the maximum temperature is 150 ° C. or lower, that is, a position 80 mm or more away from the groove line, press the backing material against the back surface of the steel plate, hold it, and weld it.

For the above reasons, in this embodiment, as shown in FIG. 1, the adhesive portion 5 of the adhesive tape 4 is separated from the groove line 2 by 80 mm or more. Then, the maximum temperature of this bonded portion becomes 150 ° C. or less, the adhesive does not fit into the steel plate, and the adhesive tape can be easily peeled off after the welding is completed.

Adhesive Strength of Adhesive Tape Adhesive strength of an adhesive tape with good adhesion to the back surface of a steel plate and a good back bead is 700 g / m for a general backing material and 2000 g / m for a backing material. This jig (described later)
When the adhesive is used at a position 80 mm away from the groove line over the entire welding line, all of the adhesive tapes having the adhesive properties shown in FIG. A good back bead was obtained, and neither the backing material nor the jig dropped after welding. That is, the adhesive strength at room temperature is 300 g
If an adhesive tape having a width of f / 10 m or more is used, a good back bead can be obtained and the jig does not drop. If a tape having a high adhesive force is used, the same welding result can be obtained without adhering the adhesive tape over the entire welding line, for example, by adhering it to a part of the pressing jig.

6 and 7 are views showing another embodiment of the present invention. FIG. 6 is a view showing the back surface of a steel plate, and FIG. 7 is a longitudinal sectional view thereof. 6 and 7, the same elements as those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted. The pushing jig 6 has a U-shaped cross section, and a flange portion 7 is provided at its side end portion. Then, the backing material 3 is arranged on the groove line 2, and the pressing jig 6 is arranged on the back surface of the backing material so as to sandwich the backing material 3 with the steel plate 1. This pushing jig 6
The collar part 7 on the back of the steel plate, and the adhesive tape 4 on the collar part 7.
It is attached to the back surface of the steel plate by adhering to the back surface of the steel plate. Therefore, the adhesive portion 5 of the adhesive tape 4 to the back surface of the steel plate is an area outside the flange portion 7 of the pressing jig 6.

The pressing jig 6 has a width of 160 mm or more in the direction orthogonal to the welding line, and is arranged with its center aligned with the groove line 2. Therefore, groove lines 2 to 8
The area of 0 mm or more is covered by this pushing jig 6,
Inevitably, the adhesion position of the adhesive tape 4 is 80 mm from the groove line 2
The positions are separated from each other as described above. In this embodiment, the adhesive tape 4 is adhered to the entire area along the groove line.

The backing material for single-sided submerged arc welding usually has a width of about 30 to 60 mm. Therefore, as shown in FIG. 1, when the pressing jig is not used, the adhesive tape 4 is pulled obliquely from the end of the backing material 3 and the tip end portion thereof is at least 80 mm away from the groove line 2. Take it like pulling and glue it. However, in this case, a force always acts on the adhesive tape 4 in the peeling direction, and it is necessary to use a tape having a high adhesive force.

On the other hand, by using the pressing jig 6 as in the present embodiment, it is possible to easily adhere with the adhesive tape at a position separated by 80 mm or more from the groove line 2. The pressing jig 6 is for allowing the adhesive force of the adhesive tape 4 to be transmitted to the backing material 3 via the pressing jig 6, and its shape is not particularly limited.

FIG. 8 shows the case where the pressing jig 6 is shallower and the backing material 3 is wider than in the case of FIG. Further, FIG. 9 shows a case where the backing material 3 is wider than that shown in FIG.

FIGS. 10 and 11 are views showing still another embodiment of the present invention. FIG. 10 is a view showing the back surface of the steel plate, and FIG.
Is a vertical sectional view thereof. The pushing jig 8 of this embodiment is the first
It is composed of a member 9, a second member 10 and a third member 11. The first member 9 has a U-shaped cross section, its convex surface is placed on the backing material 3, and extends in the longitudinal direction of the backing material 3. The second member 10 has a U-shaped cross section,
A plurality of members 9 are locally fitted and are provided. The third member 11 is provided for each second member 10,
Collar portions 12 that extend in a direction orthogonal to the groove line 2 and are in contact with the back surface of the steel sheet are provided at both ends thereof. The first member 9 and the second member 10 are connected by using an appropriate connecting member (not shown) so that the first member 9 and the second member 10 do not separate in the fitted state, but the first member 9 and the second member 10 A compression spring 13 is disposed between the inner surfaces of and, and urges them in a direction of separating them.

When the backing material 3 is held on the back surface of the steel sheet by using the pressing jig 8 thus constructed, the first member 9 is placed on the back surface of the backing material 3 as shown in FIG. Overlap, the plurality of third members 11 are pressed toward the back surface of the steel plate 1, and the flange portion 12 is pressed against the back surface of the steel plate. Then, in this state, the brim portion 12 is adhered to the back surface of the steel plate by the adhesive tape 4. In this case, the portion of the adhesive tape 4 that protrudes from the flange portion 12 becomes the adhesive portion 5, and the adhesive portion 5 is formed from the groove lines 2 to 80.
The positions are separated by more than mm.

In this embodiment, since the backing material 3 can be elastically pressed against the back surface of the steel sheet with an appropriate biasing force, a good back bead can be formed. In addition, in the present embodiment, the adhesive tape may be used in a scattered manner instead of adhering the adhesive tape over the entire area of the backing material 3, so that the adhesion work and the peeling work of the adhesive tape are facilitated. Become.

Further, as shown in FIG. 12, a plurality of separated pressing jigs 14 may be used. The pressing jig 14 has the same shape as the third member 11 of the pressing jig 8 shown in FIGS. 10 and 11, and is a strip-shaped member extending in the direction orthogonal to the groove line 2. Further, both ends of the collar portion 1 contacting the back surface of the steel plate.
It is 5. In this embodiment, the pushing jig 14 is arranged one by one on the back surface of the steel plate, and the collar portion 1 is provided by the adhesive tape 4.
It is necessary to bond 5 to the back surface of the steel plate, but this pressing jig 14 has the advantage that the structure is extremely simple and the manufacturing cost is low.

Next, the results of carrying out single-sided submerged arc welding while holding the backing material using the aluminum adhesive tape having the adhesive strength shown in Table 1 below will be described. However, the symbols in the used adhesive tape column in Table 1 correspond to the symbols in FIG. Further, the distance from the groove line of the adhesive position of the adhesive tape also represents the width of the adhesive position, and for example, 80 to 110 mm means that the width of the adhesive position is 30 mm after subtracting the width. Adhesive tape is adhered to the back of the steel plate with this width, and backing material (weight 700 g / m) and pressing jig (weight 2000 g / m)
m) was held, and two-electrode one-layer finished single-sided welding was carried out by submerged arc welding with a welding heat input of 209 KJ / cm.
The test plate is 25 mm thick, 300 mm wide and 100 mm long.
The steel plate of was used. The state of the adhesive remaining on the back surface of the steel sheet and the soundness of the back bead were investigated, and the results are shown in Table 1.

[0031]

[Table 1]

As is clear from Table 1, in the case of the examples of the present invention, the adhesive did not remain after the welding, and the removal work thereof was unnecessary. Moreover, the soundness of the back bead was also excellent. Further, the backing material and the pressing jig did not drop during the welding work.

On the other hand, in Comparative Examples 5 to 9, since the adhesion position of the adhesive tape was too close to the groove line, the adhesive strength decreased due to the temperature rise on the back surface of the steel plate, and the backing material and the pressing jig dropped. Or, the back bead was burned out, and the adhesive remained, which required removal work. Further, since Comparative Example 10 uses the pressure-sensitive adhesive G having insufficient adhesive strength at room temperature, no excessive residual bead occurred, but excessive beads were generated.

[0034]

As described above, according to the present invention,
Since the adhesive position of the adhesive tape is separated from the groove line by 80 mm or more and the adhesive strength is 300 gf / 10 mm width or more, a sound back bead can be obtained and the adhesive tape can be easily removed after welding. The adhesive can be peeled off, and there is no remaining adhesive, so the work of removing the adhesive is unnecessary and the workability of welding can be significantly improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a graph showing the relationship between temperature and adhesive strength.

FIG. 3 is a graph showing a relationship between a steel plate back surface temperature and a distance from a groove line.

FIG. 4 is a graph showing the relationship between the maximum temperature on the back surface of the steel sheet and the distance from the groove line.

FIG. 5 is a graph illustrating the remaining state of an adhesive.

FIG. 6 is a diagram showing another embodiment of the present invention.

FIG. 7 is a diagram showing a modification of the same.

FIG. 8 is a diagram showing a modification of the same.

FIG. 9 is a diagram of the same modified example.

FIG. 10 is a diagram showing another embodiment of the present invention.

FIG. 11 is a vertical sectional view of the same.

FIG. 12 is a diagram showing still another embodiment of the present invention.

[Explanation of symbols]

 1: Steel plate 2: Bevel line 3: Backing material 4: Adhesive tape 5: Adhesive part 6, 8, 14: Pushing jig 7, 12: Collar part 9, 10, 11: Member 13: Spring

Claims (3)

[Claims] 1. A single-sided submerged arc welding method in which a backing material is attached to the back surface of a plate to be welded with an adhesive tape, and one-sided submerged arc welding is performed from the front surface side of the plate to be welded, wherein the adhesive tape is at room temperature (23 ° C.). A single-sided submerged adhesive tape with a peeling adhesive strength (JIS Z0237) of 300 gf / 10 mm width or more, and the adhesive tape is adhered to the plate to be welded at a position 80 mm or more away from the groove line. Arc welding method. 2. A single-sided submerged arc welding method in which a backing material is attached to the back surface of a plate to be welded with an adhesive tape, and one-sided submerged arc welding is performed on the front surface side of the plate to be welded. Apply a tool and adhere it to the plate to be welded with the adhesive tape, which is at room temperature (23 ° C)
The peeling adhesive strength (JISZ0237) is 30
A one-sided submerged arc welding method, wherein a one having a width of 0 gf / 10 mm or more is used, and the adhesion position of the adhesive tape to the plate to be welded is a position separated by 80 mm or more from the groove line. 3. The width of the pushing jig is at least 160 mm
Above, this pushing jig is at least 80 from the groove line.
The single-sided submerged arc welding method according to claim 2, wherein the single-sided submerged arc welding is arranged on the back surface of the welded plate so as to cover the back surface region of the welded plate of mm.