JPH1158000A - Fillet welding method of steel plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the fillet welding method of a steel plate, which does not increase a required cost for edge preparation, and in which edge preparation is easily conducted, satisfactory depth of penetration and accordingly a joint having high strength is obtained. SOLUTION: Plural groove shaped recessed part 12a are formed in an end face of a steel plate 12 at an equal interval as extending in the thickness direction of the steel plate 12, by forming the recessed parts 12a, a wavy ruggedness face 12c consisting of adjacent recessed parts 12a and projecting parts 12b between the adjacent recessed parts is formed. The ruggedness face 12c of the steel plate 12 is butted so as to be vertical to the steel plate 11 on a surface of a steel plate 11 arranged horizontally, the steel plate 11 and the steel plate 12 are assembled so as to from a T shape. Successively, fillet welding is conducted for a surface side groove part 21 and a rear face side groove part 22 of the steel plate 12 by simultaneously traveling welding electrodes along the ruggedness face 12c of the steel plate 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fillet welding method applied to joint welding of a steel structure such as a T-joint.
The present invention relates to a fillet welding method for a steel sheet, which can perform pre-processing of a joint at low cost and can improve joint strength with high efficiency.

[0002]

2. Description of the Related Art In a steel structure, for example, when an I-shaped beam is manufactured and when a reinforcing member is welded, a method of fillet welding a T-joint has conventionally been applied.
FIG. 4 is a front view showing a groove portion of a conventional T-joint. FIG.
Is a T-joint in which a steel sheet 1 arranged in a horizontal direction and a steel sheet 2 arranged to be perpendicular to the steel sheet 1 are assembled so as to form a T-shape in a front view, The end face 2 b of the steel plate 2 is in contact with the surface of the steel plate 1. The end face 2b of the steel plate 2 is formed by cutting a steel plate material into a straight line, and is in a natural groove state.

[0003] In the T-joint thus assembled, the steel plate 1 and the steel plate 2 can be joined by welding from both sides of the steel plate 2. At this time, the leg length of the fillet weld bead is adjusted according to the required strength.
As described above, when a high joint strength is not required in the T joint, the groove can be machined only by cutting the end face 2b of the steel plate 2 flat along the surface of the steel plate 1.

However, when a T-joint having such a groove is welded, it is difficult to secure a desired penetration depth, so that a high joint strength cannot be obtained. Therefore, when higher joint strength is required, a method is used in which notches are provided on both sides of the end face to perform welding.

FIG. 5 is a front view showing the shape of another groove portion of a conventional T joint. The end face 4c of the steel plate 4 used for the T-joint shown in FIG. I have. Then, as in the case of the T joint shown in FIG. 4, the end face 4c of the steel plate 4 is brought into contact with the surface of the steel plate 3 arranged in the horizontal direction so as to be perpendicular to the steel plate 3, whereby Assembled to form a letter.

In the T-joint shown in FIG. 5 assembled in this manner, similarly to the case shown in FIG. 4, by welding the groove-shaped grooves formed on both sides of the steel plate 4, the steel joint 3 and the T-joint are joined together. The steel plate 4 can be joined. As described above, by performing the groove processing on the end face 4c of the steel plate 4, the throat thickness of the weld metal can be increased, and thereby the penetration depth can be improved and the high joint strength can be obtained.

[0007]

However, when welding the T joint shown in FIG. 4, in order to further increase the joint strength, for example, the penetration depth should be increased by using an extremely high welding current. However, a good weld bead shape cannot be obtained. FIG. 6 is a sectional view showing a bead shape when a T joint is welded with a high welding current. As shown in FIG. 6, when welding is performed with a high welding current to the groove 5 formed by the steel sheet 1 and the steel sheet 2, an overlap bead 6 is formed.

Another method for deepening the penetration is to provide a root gap between the steel sheet 1 and the steel sheet 2. However, if a root gap is to be formed over the entire length of the welding line, it is necessary to arrange a member such as a spacer between the steel plates when assembling the joint, and the assembly becomes complicated. In addition, there is a possibility that a root gap having a uniform appropriate width cannot be maintained during welding.

On the other hand, when the groove shape shown in FIG. 5 is formed, the penetration depth can be improved by increasing the throat thickness. However, the step of forming the notch 4a in the end face 4b of the steel plate 4 is required. Since it is necessary, the cost of processing the groove several times is required as compared with the case of the natural groove in which the end face of the steel plate is simply cut flat. In addition, it is extremely difficult to ensure dimensional accuracy such as the thickness of the root face, and the reliability of the welded joint is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and can easily process a weld groove without increasing the cost required for forming the groove. An object of the present invention is to provide a fillet welding method for a steel sheet that can obtain a penetration depth and thereby obtain a joint having high strength.

[0011]

SUMMARY OF THE INVENTION A fillet welding method for a steel sheet according to the present invention is directed to a method for welding a steel sheet in which two steel sheets are joined by fillet welding with an end face of a first steel sheet butted against a surface of a second steel sheet. In the fillet welding method, an uneven surface in which concave portions and convex portions are alternately arranged at regular intervals is formed on the end surface of the first steel plate, and formed on the front surface side and the back surface side of the first steel plate. The fillet welding is performed by simultaneously moving the welding electrode on the groove, and when the space volume of the concave portion is less than twice the volume of the convex portion, the thickness of the first steel plate is set to t (m
m), the distance between adjacent convex portions is 5 to 20 m
m, the depth of the recess is (0.1 × t) to (0.3 × t).
t) mm.

Another fillet welding method according to the present invention is a fillet welding method for a steel sheet in which an end surface of a first steel sheet is butted against a surface of a second steel sheet and the two steel sheets are joined by fillet welding. In the end surface of the first steel plate, a concave and convex surface in which concave portions and convex portions are alternately arranged at regular intervals are formed, and a groove formed on a front surface side and a back surface side of the first steel plate, At the same time, the welding electrode is moved to perform fillet welding, and when the space volume of the concave portion is at least twice the volume of the convex portion and the width of the convex portion is 8 mm or less, the thickness of the steel plate is set to t.
(Mm), the depth of the concave portion is (0.1 × t) to (0.2 × t) mm, and the distance between the convex portions is 100 mm or less.

It is preferable that the concave and convex surface is formed by forming a plurality of groove-shaped concave portions extending in a thickness direction of the first steel plate on the end surface of the first steel plate.

Further, the welding electrodes on the front side and the back side of the first steel plate are single electrodes, and a welding line between the front side welding electrode on the front side and the back side welding electrode on the back side. The distance in the direction is preferably 80 mm or less.

Further, the welding electrode on one of the front side and the back side of the first steel plate is a single electrode, and the welding electrode on the other side is a plurality of electrodes. The distance in the welding line direction between the electrode on the welding surface and the preceding electrode on the other welding surface is 8
It is desirable that it is 0 mm or less. Further, the welding electrode on the front side and the back side of the first steel plate is a plurality of electrodes,
The distance in the welding line direction between the front-side front electrode on the front side and the back-side front electrode on the back side is 80 m.
m or less.

In the method of the present invention, an uneven surface composed of a concave portion and a convex portion is formed on the end surface of the first steel plate, and the uneven surface is brought into contact with the surface of the second steel plate to form the surface of the first steel plate. The groove formed on the side and the back side is simultaneously welded. At this time,
The distance between adjacent convex portions and the depth of the concave portion are appropriately defined according to the relationship between the space volume of the concave portion and the volume of the convex portion, the width of the convex portion, and the like. Therefore, the heat capacity of the projection is reduced, and the projection can be relatively easily melted by welding heat. Further, when the convex portion on the concave and convex surface of the first steel plate is in contact with or close to the surface of the second steel plate, the concave portion is locally formed between the first steel plate and the second steel plate. Since the root gap has a preferable size, the penetration depth can be increased, and the joint strength can be increased.
Further, there is no need to maintain the root gap by temporary welding or spacers, and the assembly of members for welding is facilitated.

Furthermore, even when welding is performed under high current conditions in order to obtain deep penetration, the weld metal is absorbed by the concave portion serving as the root gap, thereby preventing the formation of an overlap bead at the groove. can do.

Further, in the method of the present invention, by forming a plurality of groove-shaped recesses extending in the thickness direction of the first steel sheet, it is possible to form an uneven surface on the end face of the first steel sheet. When such an uneven surface is formed, the plate cutting process of the end surface of the first steel plate and the formation of the concave portion can be performed simultaneously, so that a desired groove can be obtained in only one step. Therefore, the processing cost of the groove can be significantly reduced.

Further, in the method of the present invention, the distance in the welding line direction between the front side welding electrode on the front side of the first steel sheet and the back side welding electrode on the back side is defined. A similar deep penetration can be obtained in the groove formed on both sides of the groove.

Furthermore, when one or both of the front side and the back side of the first steel plate are welded with multiple electrodes, a deeper penetration can be obtained. When only one of them is welded with multiple electrodes, the distance in the welding line direction between the preceding electrode and the electrode on the other surface is preferably 80 mm or less. Further, even when both the front side and the back side are welded with multiple electrodes, it is desirable that the distance between the preceding electrodes in the direction of the welding line be 80 mm or less.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the accompanying drawings.

FIG. 1A is a front view showing a joint for explaining a fillet welding method for a steel sheet according to an embodiment of the present invention, and FIG. 1B is a side view thereof.

As shown in FIGS. 1A and 1B, a plurality of grooves are formed at one end of a steel plate (first steel plate) 12 at regular intervals so as to extend in the thickness direction of the steel plate 12. Recess 12
a is formed, and by forming this concave portion 12a, a convex portion 12b is formed between adjacent concave portions 12a. Therefore, as shown in FIG. 1B, on the end surface of the steel plate 12, the concave portions 12a and the convex portions 12b are alternately arranged, and a corrugated uneven surface 12c is formed in a plan view.
Then, on the surface of the horizontally arranged steel plate (second steel plate) 11, the steel plate 12 is set to be perpendicular to the steel plate 11.
And the steel plate 11 and the steel plate 12 are assembled so as to form a T-shape.

After assembling the joint 10 in this manner, the welding electrode is simultaneously moved along the uneven surface 12c of the steel plate 12 with respect to the front groove 21 and the back groove 22 of the steel plate 12. Weld the meat.

In this embodiment, the protrusions 12 of the steel plate 12 are used.
Since b has a small heat capacity, the protrusion 12b can be relatively easily melted by welding heat. Also, the protrusion 12b
Is in contact with the surface of the steel plate 11, and the concave portion 12a locally serves as a root gap between the steel plates 11 and 12, so that deep penetration can be obtained.

Further, in this embodiment, since there is no need to form a root gap, a spacer or the like is not required at the time of assembling the joint, so that the joint can be easily assembled. Furthermore, even when welding is performed under high current conditions in order to obtain deep penetration, the weld metal is absorbed by the concave portion 12a serving as the root gap, so that the groove portion 2 is formed.
It is possible to prevent the formation of overlap beads as shown in FIGS.

Further, in this embodiment, since the cutting of the end face of the steel plate 12 and the formation of the concave portion 12a can be performed simultaneously, a desired groove can be obtained in only one step. Therefore, the processing cost of the groove can be significantly reduced as compared with the case where the conventional groove shown in FIG. 5 is formed.

In this embodiment, the recess 12 of the steel plate 12 is used.
a and the protrusions 12b are alternately formed at regular intervals, but the distance between the adjacent protrusions 12a depends on the relationship between the space volume of the recesses 12a and the volume of the protrusions 12b, the width of the protrusions 12b, and the like. Since the depth of the concave portion 12b is appropriately defined,
Processing becomes easy, and occurrence of burn-through can be suppressed.

FIG. 2 is a plan view showing the distance P between the convex portions, the width W of the convex portions, and the depth D of the concave portions. As shown in FIG. 2, when the concave portions and the convex portions are alternately formed at a constant interval, the distances between the tips of the adjacent convex portions 12b are all the same. It is assumed that the distance between the parts is P. In addition, since the distance between the deepest grooves and the depth of the grooves in the adjacent concave portions 12a are all the same, they are referred to as the width W of the convex portion and the depth D of the concave portion, respectively.

When the space volume of the concave portion 12a is less than twice the volume of the convex portion 12b, the distance P between adjacent convex portions 12a
Is less than 5 mm, processing becomes complicated. On the other hand, if the distance P between the protrusions exceeds 20 mm, undercut or overlap occurs, and the appearance of the bead deteriorates. In addition, the depth D of the concave portion with respect to the plate thickness t (mm) of the steel plate 12.
Is less than (0.1 × t) mm, a desired penetration depth cannot be obtained, and the depth D of the concave portion is (0.2 × t) m.
If it exceeds m, undercut or overlap occurs and the bead appearance deteriorates. Therefore, when the space volume of the concave portion is less than twice the volume of the convex portion, the distance P between adjacent convex portions is 5 to 20 mm, and the depth D of the concave portion is (0.1 × t) to (0.3 × t) mm.

On the other hand, the concave portions 12a and the convex portions 12b are alternately formed at regular intervals, the spatial volume of the concave portions 12a is at least twice the volume of the convex portions 12b, and the width W of the convex portions 12b is 8 mm or less. , The distance P between adjacent convex portions
Exceeds 100 mm, undercut or overlap occurs, and the appearance of the bead deteriorates. . Further, the depth D of the concave portion is (0. 0) with respect to the thickness t (mm) of the steel plate 12.
When the depth is less than 1 × t) mm, a desired penetration depth cannot be obtained. When the depth D of the concave portion exceeds (0.2 × t) mm, undercut or overlap occurs. , The appearance of the bead deteriorates. Therefore, when the space volume of the concave portion is at least twice the volume of the convex portion and the width of the convex portion is 8 mm or less, the distance P between the convex portions is 100 mm or less, and the depth D of the concave portion is (0.
1 × t) to (0.2 × t) mm.

At the time of welding, the front side groove 21
After welding one groove portion of the back groove portion 22 and then welding the other groove portion, the unpenetrated portion (the other groove portion) is formed by the weld metal formed on one groove portion. The local route gap (concave portion 12a) in the portion (1) is filled. As a result, deep penetration can be obtained at one groove, but the penetration increasing effect is reduced at the other groove.

However, even if one groove is welded and then the other groove is welded, for example, the weld metal formed on one groove is not solidified or after solidification. If the weld metal is in a high temperature state, the effect of increasing penetration can be obtained even at the other groove portion to be welded later. When the electrode position at one groove and the electrode position at the other groove are displaced from each other, the distance between the electrodes in the welding line direction where good penetration can be obtained at both grooves is obtained by welding. Depends on conditions.

However, if the distance between the electrodes is set to 80 mm or less, deeper penetration can be obtained in any of the front-side groove 21 and the rear-side groove 22. Therefore, in this embodiment, the distance in the welding line direction between the front-side electrode on the front side of the steel plate 12 and the back-side electrode on the rear side is preferably 80 mm or less. In addition, it is preferable that the distance in the welding line direction between the front surface side electrode and the back surface side electrode is small, and it is even more preferable that opposite positions on the front surface side and the back surface side are simultaneously welded.

Further, when one or both of the front side and the back side of the steel plate 12 are welded with multiple electrodes, a deeper penetration can be obtained. When only one of them is welded with multiple electrodes, the distance in the welding line direction between the preceding electrode and the electrode on the other surface is preferably 80 mm or less. When both front and back sides are to be welded with multiple electrodes, the distance between the preceding electrodes in the direction of the weld line is set to 80 mm.
mm or less.

[0036]

EXAMPLES Examples of welded joints obtained by using the welding method according to the present invention will be specifically described below in comparison with comparative examples.

First Example First, a T-joint was welded by the welding method according to the present invention and a conventional welding method, and a penetration depth comparison test was performed. FIG.
FIG. 3 is a front view showing a shape of a T-joint used in a penetration depth comparison test and a target position of a wire. First, the end surface 13a of the steel plate 13 was applied to the surface of the horizontally disposed steel plate 14 so as to be perpendicular to the steel plate 14, and a T joint was assembled. However, as an example, the end surface 13a of the steel plate 13 is used.
In addition, a plurality of groove-shaped concave portions and convex portions extending in the thickness direction of the steel plate 13 were formed by varying the depth D of the concave portions, the distance P between the convex portions, and the width W of the convex portions. In Examples and Comparative Examples, the thickness of the steel plate 14 was 25 mm,
The thickness of No. 3 was two types, 14 mm and 25 mm.

Next, these T joints were welded from only one side under the conditions shown in Table 1 below using a single electrode submerged arc welding method. As a welding material, a commercially available wire 15 having a wire diameter of 4 mm and a commercially available molten flux were used, and the angle between the steel plate 14 and the wire 15 was 45 ° as shown in FIG. , Wire 1
5 was arranged. Then, the appearance of the weld bead after welding was observed, the occurrence of undercut or overlap was investigated, and a cross-sectional macro was sampled from the welded portion to evaluate the penetration depth. The production conditions and evaluation results of the steel plate 13 are shown in Tables 2 to 9 below.

In the evaluation result column of the appearance, those in which undercut and overlap did not occur were evaluated as ○, and the others were evaluated as ×. In addition, in the penetration evaluation result column, a penetration depth of 45% or more of the thickness of the steel sheet 13 at the time of single-side welding is used as a criterion for obtaining a joint that is close to full penetration when both sides of the steel sheet 13 are welded. Was obtained, and the other samples were evaluated as x. In addition, since the evaluation result of the external appearance was unacceptable, what did not perform the penetration evaluation test was set to-.

[0040]

[Table 1]

[0041]

[Table 2]

[0042]

[Table 3]

[0043]

[Table 4]

[0044]

[Table 5]

[0045]

[Table 6]

[0046]

[Table 7]

[0047]

[Table 8]

[0048]

[Table 9]

As shown in Tables 2 to 9 above, Example N
o. In Nos. 1 to 21, the uneven surface of the desired size was formed on the end face of the steel plate 13, so that the bead appearance was excellent and the penetration of 45% or more could be obtained by single-side welding. Thereby, it was shown that when the front surface side and the back surface side of the steel plate 13 were welded under the same conditions, a penetration almost complete penetration was obtained.

On the other hand, Comparative Example No. In Nos. 22 to 24, 29 to 32 and 36, the depth D of the concave portion was less than the lower limit of the range of the present invention, so that a sufficient penetration depth could not be obtained. Comparative Example No. In 25 to 27, 33, and 34, since the depth D of the concave portion exceeded the upper limit of the range of the present invention, the appearance of the bead was poor. Also, in Comparative Example No. In No. 28, the penetration W was insufficient because the width W of the convex portion exceeded the condition range of the present invention and the depth D of the concave portion exceeded the upper limit of the present invention range. Comparative Example No. In No. 35, the bead appearance was poor because the width W of the convex portion exceeded the condition range of the present invention.

Second Example Next, a T-joint was welded by the welding method according to the present invention and a conventional welding method, and the penetration states of the respective welded portions were compared. The shape of the T joint and the angle of the wire used in the penetration state comparison test were the same as in the first embodiment. In addition, about an Example and a comparative example, the steel plate 13 and 14 each set the board thickness to 25.
mm.

Next, these T joints were welded from both sides under the conditions shown in Table 10 below using a single electrode submerged arc welding method. As a welding material, a commercially available wire having a wire diameter of 4 mm and a commercially available molten flux were used.
Welding was performed with the distance in the welding line direction between the wires varied. Thereafter, the appearance of the weld bead was observed to investigate the occurrence of undercut or overlap, and a cross-sectional macro was sampled from the welded portion to evaluate the penetration depth. The production conditions and evaluation results of the steel plate 13 are shown in Tables 11 and 12 below.

In the evaluation result column for appearance, those in which undercut and overlap did not occur were evaluated as ○, and the others were evaluated as ×. In the column of the evaluation results of the penetration, the root face at the end face of the steel plate 13 did not remain, and the case where complete penetration was obtained was evaluated as ○, and the case where penetration on the rear electrode side was slightly insufficient was evaluated as Δ. And the others were marked as x.

[0054]

[Table 10]

[0055]

[Table 11]

[0056]

[Table 12]

As shown in Tables 11 and 12, Example No. 51 to 58 are formed with an uneven surface of a desired size on the end surface of the steel plate 13, and the surface side and the back surface side of the steel plate 13 are fillet welded in a state where the uneven surface is in contact with the surface of the steel plate 14. As a result, bead appearance was excellent and deep penetration was able to be obtained. In particular, in Example No. 52
In Nos. 58 to 58, the distance in the welding line direction between the electrodes was 80 mm or less, so that a sufficiently deep penetration could be obtained on any of the welding surfaces on the front side and the back side.

On the other hand, in Comparative Example No. In No. 59, the penetration D was incomplete because the depth D of the concave portion was less than the lower limit of the range of the present invention. Comparative Example No. In Nos. 60 and 61, since the depth D of the concave portion exceeded the upper limit of the range of the present invention, the appearance of the bead was poor. Comparative Example No. In No. 62, since no uneven surface was formed on the end face of the steel plate 13, the appearance of the bead became poor and complete penetration could not be obtained.

Third Embodiment Next, a joint similar to the T joint used in the second embodiment was assembled, and this T joint was simultaneously subjected to fillet welding from the surface side of the steel plate 13 by two-electrode tandem welding.
The penetration of the weld was investigated. The shape of the T joint used in the penetration state comparison test and the angle of the wire in a plane perpendicular to the direction of the welding line were the same as in the first embodiment. The steel plate 13 has a thickness of 25 mm and a depth D of the concave portion.
Is 4.5 mm, the distance P between the projections is 12 mm, and the width W of the projections is
Was set to 6 mm. The distance in the welding line direction of the leading electrode on the front side and the back side of the steel plate 13 was 0 mm. Table 13 below shows the welding conditions. However, the angles of the wires shown in Table 13 below are the inclination angles of the wires in the direction of the welding line.

[0060]

[Table 13]

After performing the welding under the conditions shown in Table 13 above, the appearance and penetration depth of the bead were evaluated. As a result, good results were obtained on the front side and the back side of the steel plate 13. Further, since welding was performed with two electrodes on any of the welding surfaces, the welding efficiency could be further improved as compared with the case of single electrode welding.

[0062]

As described in detail above, according to the present invention,
The uneven surface of the desired size formed on the end face of the steel sheet is brought into contact with the surface of another steel sheet, and the front side and the back side of this steel sheet are simultaneously welded, so that a deep penetration can be obtained, and the joint strength can be improved. Can be enhanced. Further, processing and assembly for welding can be easily performed at low cost. Furthermore,
Forming a groove-shaped recess extending in the thickness direction of the steel sheet further facilitates processing and assembly. Furthermore, when the distance in the welding line direction between the front side welding electrode on the front side of the steel sheet and the back side welding electrode on the back side is specified, a deeper penetration can be obtained.

[Brief description of the drawings]

FIG. 1A is a front view showing a joint for explaining a fillet welding method for a steel sheet according to an embodiment of the present invention;
(B) is a side view thereof.

FIG. 2 shows a distance P between convex portions, a width W of convex portions, and a depth D of concave portions.
FIG.

FIG. 3 is a front view showing a shape of a T-joint and a target position of a wire used in a penetration depth comparison test.

FIG. 4 is a front view showing a groove portion of a conventional T-joint.

FIG. 5 is a front view showing the shape of another groove portion of a conventional T-joint.

FIG. 6 is a cross-sectional view showing a bead shape when a T joint is welded with a high welding current.

[Explanation of symbols]

 1, 2, 3, 4, 11, 12, 13, 14; steel plate 6; overlap bead 10; joint 12a; concave portion 12b; convex portion 12c;

Claims (10)

[Claims] 1. A fillet welding method for a steel sheet in which an end face of a first steel sheet is abutted against a surface of a second steel sheet and two steel sheets are joined by fillet welding, wherein the end face of the first steel sheet is Forming a concave and convex surface in which concave portions and convex portions are alternately arranged at regular intervals, and performing fillet welding on a groove formed on the front side and the back side of the first steel sheet by simultaneously moving a welding electrode. When the space volume of the concave portion is less than twice the volume of the convex portion, the thickness of the first steel plate is set to t (m
m), the distance between adjacent convex portions is 5 to 20 m
m, the depth of the recess is (0.1 × t) to (0.3 × t).
t) mm, a method for welding a fillet of a steel sheet. 2. The uneven surface is formed by forming a plurality of groove-shaped concave portions extending in a thickness direction of the first steel plate on the end surface of the first steel plate. The method for welding a fillet of a steel sheet according to claim 1. 3. The welding electrode on the front side and the back side of the first steel plate is a single electrode, and a welding line between the front side welding electrode on the front side and the back side welding electrode on the back side. 3. The method according to claim 1, wherein the distance in the direction is 80 mm or less. 4. The welding electrode on one of the front side and the back side of the first steel plate is a single electrode, and the welding electrode on the other side is a plurality of electrodes. The distance in the welding line direction between the electrode on the welding surface and the preceding electrode on the other welding surface is 80 m.
3. The method for welding a fillet of a steel sheet according to claim 1, wherein the thickness is not more than m. 5. The welding electrode on the front side and the back side of the first steel plate is a plurality of electrodes, and a welding line between the front side front electrode on the front side and the back side front electrode on the back side. 3. The method according to claim 1, wherein the distance in the direction is 80 mm or less. 6. A fillet welding method for a steel sheet in which an end face of a first steel sheet is abutted against a surface of a second steel sheet and two steel sheets are joined by fillet welding, wherein the end face of the first steel sheet is Forming a concave and convex surface in which concave portions and convex portions are alternately arranged at regular intervals, and performing fillet welding on a groove formed on the front side and the back side of the first steel sheet by simultaneously moving a welding electrode. When the space volume of the concave portion is at least twice the volume of the convex portion and the width of the convex portion is 8 mm or less, the depth of the concave portion is set to (0. 1 × t)
A fillet welding method for a steel plate, wherein the distance between the convex portions is 100 mm or less. 7. The uneven surface is formed by forming a plurality of groove-shaped recesses extending in a thickness direction of the first steel plate on the end surface of the first steel plate. The method for welding fillet of a steel sheet according to claim 6. 8. The welding electrode on the front side and the back side of the first steel plate is a single electrode, and a welding line between the front side welding electrode on the front side and the back side welding electrode on the back side. The fillet welding method for a steel sheet according to claim 6, wherein the distance in the direction is 80 mm or less. 9. The welding electrode on one of the front surface side and the back surface side of the first steel plate is a single electrode, and the welding electrode on the other welding surface is a plurality of electrodes, and The distance in the welding line direction between the electrode on the welding surface and the preceding electrode on the other welding surface is 80 m.
8. The method according to claim 6, wherein the thickness is not more than m. 10. The front-side and back-side welding electrodes of the first steel sheet are a plurality of electrodes, and a welding line between the front-side front electrode on the front side and the back-side front electrode on the back side. The fillet welding method for a steel sheet according to claim 6, wherein the distance in the direction is 80 mm or less.