JP3383075B2 - Single-sided submerged arc welding method - Google Patents

Description

Description: 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 backside of a plate to be welded and single-sided submerged arc welding is performed from the surface side of the plate to be welded. More specifically, the present invention relates to a single-sided submerged arc welding method in which a simple backing material is attached to a groove position on the back surface of a 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. In a single-sided submerged arc welding method for a steel sheet using a simple backing material, a backing material is attached to a groove on the back surface of the steel plate to be welded. Conventionally, as a method to adhere to the back of the steel plate, after applying a backing plate to the back of the backing material with an aluminum plate, etc.
A method of pushing up an aluminum plate with a magnet or a wedge or the like and bringing a backing material into close contact with the back surface of the steel plate has been often used. [0003] However, in the case of a joint having a long welding length and a joint having insufficient space for the operation, it is necessary to carry a heavy magnet or wedge and a jig for mounting to a welding location, to mount the same, and to remove the same. This was a significant burden and reduced the efficiency of the welding operation. In addition, a heavy magnet may come off during welding and fall off, resulting in a serious safety problem. [0004] In order to solve such problems, the present applicant has developed a method of attaching a backing material using a lightweight adhesive tape which is easy to attach and detach, and has already filed an application (Japanese Patent Application Laid-Open (JP-A) no. Kaihei 5-161975). As the adhesive tape, a tape having a predetermined adhesive force even at a high temperature is used. When the backing material is attached with this adhesive tape, even in large heat input submerged arc welding, the adhesion of the backing material is good, and a sound back bead can be secured. [0005] However, when the backing material is attached to the back surface of the steel plate using this adhesive tape, the adhesive remains on the back surface of the steel plate when the backing material is removed after welding. However, there is a disadvantage that a great deal of time is wasted in the work of removing the adhered adhesive. The present invention has been made in view of the above problems, and has a drawback when a backing material is attached by an adhesive tape, that is, an adhesive remains on the back surface of a steel sheet after the backing material is removed after welding. One side that can easily attach and remove the backing material without the need to remove the adhesive remaining on the back of the steel plate, as well as secure a healthy back bead. An object of the present invention is to provide a submerged arc welding method. A single-sided submerged arc welding method according to the present invention comprises attaching a backing material to the back surface of a plate to be welded with an adhesive tape, and performing single-sided submerged arc welding on the surface side of the plate to be welded. In the single-sided submerged arc welding method to be performed, a pressing jig is applied to the back surface of the backing material and adhered to the plate to be welded with the adhesive tape, and the adhesive tape is peeled at normal temperature (23 ° C.) (JISZ023).
7) using more than 300 gf / 10 mm width, Ri position der adhesion position or more away 80mm from the groove line to the object to be welded plates of this adhesive tape, the width of the pressing jig small
At least 160 mm
To cover the back side of the plate to be welded 80mm from the groove line
Characterized Rukoto arranged to be welded plate rear surface. The present inventors have repeated various experimental studies in order to develop a method capable of preventing the adhesive from remaining after welding and simplifying the attachment and detachment of the backing material. As a result, the following facts were found. That is, in the conventional method of attaching a backing material with an adhesive tape, a backing material having a width of about 30 to 60 mm is generally arranged on the back surface of a steel plate, and the backing material is covered with the backing material and the backing material. Adhesive tape was adhered to the back of the steel plate where it was not, and the backing material was attached to the back of the steel plate. For this reason, since the adhesive part of the adhesive tape on the back surface of the steel plate is close to the welding line, the temperature of the adhesive part increases after the arc has passed. As described above, when the temperature of the bonding portion increases, the viscosity of the ordinary organic pressure-sensitive adhesive decreases, and the normal organic pressure-sensitive adhesive adapts well to the steel sheet. For this reason, after the welding has been completed and the temperature of the steel sheet has dropped to some extent, when the adhesive tape is to be peeled off, the adhesive tape adheres to the steel sheet back surface in a state where the adhesive has adjusted to the steel sheet back surface. It remains on the back of the steel plate. The adhesive remaining on the back surface of the steel sheet needs to be removed because it impairs the paintability, and this removal operation requires an extremely long time, which significantly impairs welding workability. Based on these facts, the inventors of the present invention have conducted various studies in order to develop a method capable of avoiding the residual adhesive, and as a result, have found that an adhesive tape is adhered to a groove near a groove having a high back surface temperature of a steel sheet. At a temperature of 150 ° C. or less, that is, at a position 80 mm or more away from the groove, at room temperature (2
3 ° C) (JISZ0237)
When a pressure-sensitive adhesive tape having a width of 300 gf / 10 mm or more is bonded, a rise in the temperature of the steel sheet at the bonding position of the pressure-sensitive adhesive tape is small, the adhesion of the backing material during welding is good, and a sound back bead is obtained. When the backing material was removed, no adhesive remained on the back surface of the steel sheet, and it was found that the work of removing the residual adhesive was unnecessary. The present invention has been made from such a viewpoint. In order to adhere the adhesive tape at a position (80 mm or more) away from the groove line and to ensure sufficient adhesion of the backing material to the back surface of the steel plate, a lightweight pressing jig must be used. The pressing jig may be arranged on the back surface of the material, and the pressing jig may be adhered to the back surface of the steel plate with an adhesive tape. Embodiments of the present invention will be specifically described below with reference to the accompanying drawings. First, a first embodiment of the present invention will be described with reference to FIG. FIG.
(A) is a figure which shows the back surface of a steel plate, FIG.1 (b) is the longitudinal cross-sectional view. The butted ends of the steel plate 1 as the plate to be welded are chamfered at an angle, and the pair of steel plates 1 are butted so that a V-shaped groove is formed on the surface side. A backing material 3 is arranged on the back surface of the steel sheet 1 at a position centered 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 by the adhesive tape 4. The adhesive tape 4 has adhesive portions 5 on both sides thereof, and is adhered to the back surface of the steel plate by the adhesive portions 5. Thus, in this embodiment, each of the adhesive portions 5 is located at a distance of 80 mm or more from the groove 2. The adhesive strength and the distance from the groove line are specified in JISZ0237. The peel strength of the adhesive tape (hereinafter simply referred to as "adhesive strength") mainly depends on the type of the adhesive and the application of the adhesive. Determined by thickness and temperature. FIG. 2 is a graph showing the relationship between the temperatures of the pressure-sensitive adhesives A to G and the adhesive force, with the horizontal axis representing the test temperature and the vertical axis representing the adhesive force. Each of the adhesives has the highest adhesive strength at room temperature, and decreases as the temperature increases. 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 greatly reduced from a temperature exceeding 100 ° C. Therefore, until the back bead is completely formed (the weld metal is solidified), it is necessary to hold the backing material by bonding an adhesive tape to a position where the back surface temperature of the steel sheet does not increase to 100 ° C. or more. [0015] Locations Figure 3 from the back surface temperature and the groove line of the steel plate taking the distance from the groove line 2 on the horizontal axis, the vertical axis represents the steel sheet surface temperature during penetration bead formation, various thickness It is a graph which shows the relationship between the distance from the 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 three types of steel plates having a thickness of 16 mm, 19 mm and 25 mm were subjected to single-layer welding on one side of the submerged arc using a simple backing material, and the leading electrode considered to have completely formed the back bead. It is the result of measuring the back surface temperature of the steel plate at a position 100 mm rearward from. As described above, since the temperature at which stable adhesive strength of the adhesive tape is obtained is 100 ° C. or less, in order to maintain the adhesion of the backing material until the formation of the back bead is completed, it is determined from this measurement result. Then, it is understood that it is necessary to adhere the adhesive tape at a position at least 35 mm or more away from the groove line. Temperature of Steel Backside and Residual Adhesive The relationship between the maximum temperature of the steel backside and the presence or absence of adhesive remaining on the steel backside when the adhesive tape is peeled off using an adhesive tape having the adhesive properties shown in FIG. investigated. as a result,
Both adhesive tapes have a maximum backside temperature of 150 ° C
When the above was reached, the amount of the remaining spreading agent rapidly increased. FIG.
The horizontal axis is the distance from the groove line, and the vertical axis is the maximum temperature of the steel plate back surface.The relationship between the distance from the groove line and the steel plate back surface maximum temperature for various sheet thicknesses and groove shapes is shown. FIG. As is clear from FIG. 4, under any conditions, when the distance from the groove of the steel sheet is 80 mm or more, the maximum temperature of the back surface of the steel sheet becomes approximately 150 ° C. or less. Good back bead without adhesive on the back of 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 steel plate back surface temperature at the end of back bead formation is 100 ° C. or less, that is, 35 ° from the welding line.
An adhesive tape may be attached to a position separated by at least mm. However, after the welding is completed, when the adhesive tape is peeled off, in order to prevent the adhesive from remaining on the steel sheet back surface, the maximum temperature of the steel sheet back surface is about 150 ° or less, that is, a position at least 80 mm away from the groove line. It is necessary to glue the adhesive tape to Therefore, as shown in FIG. 5, in order to obtain a good back beat and to prevent the adhesive from being left on the back surface of the steel plate when the backing material is removed after the welding, the back surface of the steel plate is required. It is necessary to adhere an adhesive tape to a position where the maximum temperature of the steel sheet is 150 ° C. or less, that is, a position 80 mm or more from the groove line, hold the backing material against the back surface of the steel sheet, and weld. 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 2 by 80 mm or more. In this case, the temperature of the bonded portion is 150 ° C. or less at the maximum temperature, the adhesive does not adapt to the steel plate, and the adhesive tape can be easily peeled off after the welding is completed. Adhesive Strength of Adhesive Tape The adhesive force of the adhesive tape, which has good adhesion to the back surface of the steel sheet and provides a good back bead, includes a general backing material of 700 g / m and a pressing force of 2000 g / m. This jig (to be described later)
When the adhesive is applied over the entire welding line at a position 80 mm away from the groove line, all the adhesive tapes having adhesive properties shown in FIG. A good back bead was obtained, and the backing material and the jig did not drop 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 fall. If a tape having a high adhesive strength is used, a similar welding result can be obtained without adhering the adhesive tape over the entire welding line, for example, only by adhering to a part of the pressing jig. FIGS. 6 and 7 show another embodiment of the present invention. FIG. 6 is a view showing a 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 denoted by the same reference numerals, and detailed description thereof will be omitted. The pressing jig 6 has a U-shaped cross section, and a flange 7 is provided at a side end thereof. The backing material 3 is arranged on the groove 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 pressing jig 6
Overlaps the flange 7 on the back surface of the steel plate and attaches the adhesive tape 4 to the flange 7
It is attached to the back surface of the steel plate by bonding over the steel plate back surface. Therefore, the bonding portion 5 of the adhesive tape 4 to the back surface of the steel plate is a region outside the flange 7 of the pressing jig 6. The pressing jig 6 has a width of at least 160 mm in a direction perpendicular to the welding line, and is arranged so that its center coincides with the groove line 2. For this reason, groove lines 2 to 8
The area of 0 mm or more is covered by the pressing jig 6,
Inevitably, the adhesive position of the adhesive tape 4 is 80 mm from the groove 2
The positions are separated as described above. In this embodiment, the adhesive tape 4 is adhered to the whole area along the groove line. The backing material for single-sided submerged arc welding usually has a width of usually 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 thereof is positioned at least 80 mm away from the groove 2. Take as if pulling and glue. However, in this case, a force always acts in the direction in which the adhesive tape 4 is peeled off, 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 an adhesive tape at a position separated from the groove 2 by 80 mm or more. The pressing jig 6 is for transmitting the adhesive force of the adhesive tape 4 to the backing material 3 via the pressing jig 6, and the shape thereof is not particularly limited. FIG. 8 shows a case where the pressing jig 6 is shallower and the backing material 3 is wider than in FIG. FIG. 9 shows a case where the backing material 3 is wider than the case of FIG. FIGS. 10 and 11 show still another embodiment of the present invention. FIG.
Is a longitudinal sectional view thereof. The pressing jig 8 of the present embodiment is
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, is arranged with its convex side overlapping 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. The third member 11 is provided for each second member 10,
A flange portion 12 extending in a direction perpendicular to the groove line 2 and contacting the back surface of the steel plate is provided at both ends. The first member 9 and the second member 10 are connected using an appropriate connecting member (not shown) so that the first member 9 and the second member 10 are not detached in a state where they are fitted. A compression spring 13 is disposed between the inner surfaces of the two and biases them in a direction to separate them. When the backing material 3 is held on the back surface of the steel plate by using the pressing jig 8 configured as described above, the first member 9 is attached to the back surface of the backing material 3 as shown in FIG. Then, the plurality of third members 11 are pressed toward the back surface of the steel plate 1, and the flange 12 is pressed against the back surface of the steel plate. Then, in this state, the flange 12 is adhered to the back surface of the steel plate by the adhesive tape 4. In this case, the part of the adhesive tape 4 that protrudes from the flange 12 becomes the bonding part 5, and the bonding part 5 is separated from the groove 2 by 80.
mm or more. In this embodiment, since the backing material 3 can be elastically pressed against the back surface of the steel plate with an appropriate urging force, a good back bead can be formed. Further, in the present embodiment, the adhesive tape may be used in an interspersed manner instead of adhering the adhesive tape over the entire area of the backing material 3, so that the adhesive tape bonding operation and the peeling operation can be easily performed. Become. Further, as shown in FIG. 12, a plurality of separated pressing jigs 14 may be used. This pressing jig 14 has the same shape as the third member 11 of the pressing jig 8 in FIGS. 10 and 11, and has a band shape extending in a direction orthogonal to the groove line 2. And the both ends are the flanges 1 contacting the back of the steel plate.
It is 5. In this embodiment, the pressing jigs 14 are arranged one by one on the back surface of the steel plate, and the flange 1
5 needs to be bonded 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 single-sided submerged arc welding with the backing material held using an aluminum adhesive tape having the adhesive strength shown in Table 1 below will be described. However, the symbols in the column of adhesive tape used in Table 1 correspond to the symbols in FIG. The distance from the groove to the adhesive position of the adhesive tape also indicates the width of the adhesive position. For example, 80 to 110 mm indicates that the width of the adhesive position is 30 mm after subtraction. Adhesive tape is adhered to the back of the steel sheet with this width, and the backing material (weight 700 g / m) and the pressing jig (weight 2000 g / m)
m), and two-electrode, one-layer finish single-sided welding was performed by submerged arc welding with a welding heat input of 209 KJ / cm.
The test plate is 25mm thick, 300mm wide and 100mm long
Steel plate was used. The remaining condition of the adhesive on the back surface of the steel sheet and the soundness of the back bead were examined, and the results are shown in Table 1. [Table 1] As is apparent from Table 1, in the case of the embodiment of the present invention, the adhesive did not remain after welding, and the work for removing the adhesive was unnecessary. Also, the soundness of the back bead was excellent. Further, the backing material and the pressing jig did not drop during the welding operation. On the other hand, in Comparative Examples 5 to 9, since the adhesive position of the adhesive tape was too close to the groove line, the adhesive force was reduced due to the temperature rise on the back surface of the steel sheet, and the backing material and the pressing jig fell. In addition, the back bead may be dropped off, and the adhesive may remain. In Comparative Example 10, since the adhesive G having insufficient adhesive strength at room temperature was used, an excessive bead was generated although no adhesive remained. As described above, according to the present invention,
The adhesive position of the adhesive tape is separated from the groove line by 80 mm or more, and the adhesive force is 300 gf / 10 mm width or more. Therefore, a sound back bead can be obtained, and the adhesive tape can be easily removed after welding. Since there is no remaining adhesive, there is no need to remove the adhesive, and the welding workability can be significantly improved.

BRIEF DESCRIPTION OF THE 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 the relationship between the back surface temperature of a steel sheet and the distance from a groove line. FIG. 4 is a graph showing the relationship between the maximum temperature of the steel plate rear surface and the distance from the groove line. FIG. 5 is a graph illustrating the state of remaining 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 view showing a modified example of the same. FIG. 10 is a diagram showing another embodiment of the present invention. FIG. 11 is a longitudinal sectional view of the same. FIG. 12 is a diagram showing still another embodiment of the present invention. [Description of Signs] 1: Steel plate 2: Edge line 3: Backing material 4: Adhesive tape 5: Adhesive parts 6, 8, 14: Pressing jigs 7, 12: Collar parts 9, 10, 11: Member 13 :spring

Claims (1)

(57) [Claim 1] A single-sided submerged arc welding method in which a backing material is attached to the backside of a plate to be welded with an adhesive tape and single-sided submerged arc welding is performed on the surface side of the plate to be welded. A pressing jig is applied to the back surface of the backing material and adhered to the plate to be welded with the adhesive tape, and the adhesive tape is at room temperature (23 ° C.).
Peel strength (JISZ0237) of 30
Using the 0 gf / 10 mm in width or more, Ri position der adhesion position or more away 80mm from the groove line to the object to be welded plates of this adhesive tape, the width of the pressing jig least 1
60mm or more, and this pressing jig is at least
To be welded so as to cover the back surface area of
It sided submerged arc welding method according to claim Rukoto disposed on the rear surface.