JP2017205796A - Manufacturing method of welding structure, and welding structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a welding structure having excellent fatigue strength.SOLUTION: A manufacturing method of a welding structure is the manufacturing method for manufacturing the welding structure by processing a welding joint. The welding joint comprises a first member and a second member welded to an end surface of the first member, and the first member has a crack extending from an end part of a welding part with the second member. The manufacturing method comprises a process (Step S1) of forming a groove penetrating through the first member in a part of including the crack of the first member, a process (Step S2) of forming a joining part by conducting fillet-welding of a backing strip for covering the groove on one surface of the first member, a process (Step S3) of forming welding metal by conducting repair-welding of the groove from the other surface of the first member, and a process (Step S5) of peening the joining part after forming the welding metal with the backing strip left.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for manufacturing a welded structure and a welded structure. More particularly, the present invention relates to a manufacturing method for manufacturing a welded structure by processing a welded joint, and the welded structure.

  Some equipment such as crane gutters have in-plane gusset joints. In-plane gusset joints have low fatigue strength, and fatigue cracks are particularly likely to occur from the end of the weld. Therefore, regular repair is necessary.

  Repair of equipment in which a fatigue crack has occurred is performed by removing a portion having the fatigue crack and repair welding the portion. However, even if repair welding is simply performed, fatigue cracks are immediately generated due to welding residual stress. For this reason, the weld toe is subjected to curvature processing, or residual compressive stress is applied to the weld toe by ultrasonic impact treatment.

  Japanese Patent Application Laid-Open No. 2004-167515 discloses a repair welded portion that has undergone welding repair after removing a fatigue cracked portion, and the weld toe of the repair welded portion is subjected to an ultrasonic shock treatment at a temperature of 100 ° C. or less. A method for repairing a girder structure with a flange gusset that improves the toe shape by forming a groove is disclosed.

  Although it is not explicitly described in the above publication, when repair welding is performed, welding is performed after a backing metal is temporarily fixed to the repair weld portion. As described in Japan Steel Structure Association, “Fatigue Design Guidelines for Steel Structures and Commentary”, 2012 revised edition, Gihodo Publishing, June 2012, page 38, leaving backing metal If left untreated, it is known that the strength grade is greatly reduced. Therefore, the backing metal needs to be removed by a grinder after repair welding.

JP 2004-167515 A

Edited by Japan Steel Structure Association, “Fatigue Design Guidelines for Steel Structures and Explanation”, 2012 revised edition, Gihodo Publishing, June 2012

  In equipment such as crane garters, repairs may cause fatigue failure to recur from the welded parts and their surroundings in welded welded structures.

  An object of the present invention is to provide a method for producing a welded structure having excellent fatigue strength. Another object of the present invention is to provide a welded structure having excellent fatigue strength.

  The manufacturing method of the welded structure by one Embodiment of this invention is a manufacturing method which processes a welded joint and manufactures a welded structure, Comprising: The said welded joint is a 1st member and the end surface of the said 1st member. A welded second member, wherein the first member has a crack extending from an end of a welded portion with the second member, and the manufacturing method includes a portion of the first member including the crack. Forming a groove that penetrates the first member; forming a joint by filling a backing metal that covers the groove on one surface of the first member; and the first member. And repairing the groove from the other surface to form a weld metal, and forming the weld metal and then peening the joint, leaving the backing metal.

  A welded structure according to an embodiment of the present invention includes a first member, a second member welded to an end surface of the first member, an end surface welded to the second member of the first member, and the A weld metal that penetrates the first member in the thickness direction, a backing metal that covers the weld metal with one surface of the first member, the one surface of the first member, and an end surface of the backing metal; And a joint portion that joins each other. The joint portion is peened.

  According to the present invention, a welded structure having excellent fatigue strength can be obtained.

FIG. 1 is a perspective view of an in-plane gusset joint. FIG. 2 is a flowchart of the method for manufacturing a welded structure according to the first embodiment of the present invention. FIG. 3 is a perspective view of the in-plane gusset joint when a portion including the crack CR is removed from the flange to form a groove. FIG. 4 is a plan view showing the back surface of the in-plane gusset joint when the backing metal is fillet welded. FIG. 5 is a perspective view of an in-plane gusset joint when a weld metal is formed. FIG. 6 is a perspective view of the in-plane gusset joint when the backing metal is cut. FIG. 7 is a plan view showing the surface of the welded structure manufactured by the manufacturing method according to the first embodiment of the present invention. 8 is a cross-sectional view taken along line VIII-VIII in FIG. FIG. 9 is a plan view showing the back surface of the welded structure manufactured by the manufacturing method according to the present embodiment. FIG. 10 is a plan view showing a back surface of a welded structure according to a modification. FIG. 11 is a plan view showing a back surface of a welded structure according to another modification. FIG. 12 is a flowchart showing a method for manufacturing a welded structure according to the second embodiment of the present invention. FIG. 13 is a perspective view of a welded structure manufactured by the manufacturing method according to the second embodiment of the present invention. FIG. 14 is a flowchart showing a method for manufacturing a welded structure according to the third embodiment of the present invention. FIG. 15A is a plan view of an in-plane gusset joint for testing. FIG. 15B is a side view of a test in-plane gusset joint.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated. The dimensional ratio between the constituent members shown in each drawing does not necessarily indicate the actual dimensional ratio.

[First Embodiment]
The method for manufacturing a welded structure according to the present embodiment is a method of processing an in-plane gusset joint having a crack into a welded structure. FIG. 1 is a perspective view of an in-plane gusset joint 10 processed in the present embodiment. The in-plane gusset joint 10 includes a flange 11 and a gusset 12 welded to an end face of the flange 11. The flange 11 has a crack CR extending from the end 13 a of the welded portion 13 with the gusset 12.

  FIG. 2 is a flowchart of the method for manufacturing a welded structure according to the first embodiment of the present invention. 3-6 is a figure which shows the structure of the in-plane gusset joint in the middle of a process.

  The manufacturing method according to the present embodiment includes a step (step S1) of forming a groove 11A (FIG. 3) penetrating the flange 11 in a portion 11a including the crack CR of the flange 11, and a groove 11A on one surface of the flange 11. A step (step S2) of forming a joint 15 (FIG. 4) by fillet welding the backing metal 14 (FIG. 3) covering the metal, and repair welding the groove 11A from the other surface of the flange 11 to weld metal 16 (FIG. 5) forming step (step S3), cutting the backing metal 14 (step S4), forming the weld metal 16, then peening the joint 15 (step S5), welding And a step of peening the metal 16 (step S6). Hereinafter, each process is explained in full detail.

[Step of forming groove]
The portion 11a including the crack CR of the flange 11 is removed (step S1). FIG. 3 is a perspective view of the in-plane gusset joint when the portion 11a (FIG. 1) including the crack CR is removed from the flange 11 to form the groove 11A. In this example, a groove 11A having a V-shaped cross section is formed in order to facilitate repair welding described later. Specifically, the groove 11A has a shape in which the area gradually decreases from one surface of the flange 11 toward the other surface. However, the cross section of the groove 11A may have a shape other than the V shape.

  At this time, in order to ensure workability, the portion 12 a (FIG. 1) near the crack Cr may be removed from the gusset 12. When the portion 12a in the vicinity of the crack Cr is removed from the gusset 12, the stress tends to concentrate on the end portion 13b (FIG. 3) of the welded portion 13. Therefore, it is preferable to reduce the concentration of stress on the end portion 13b by processing the cut surface to be a curved surface.

[Process for fillet welding the backing metal]
The joining metal 15 (FIG. 4) is formed by fillet welding the backing metal 14 covering the groove 11A on one surface of the flange 11 (step S2). Hereinafter, of the front and back surfaces of the flange 11, the surface to which the backing metal is attached is referred to as “back surface”, and the opposite surface is referred to as “front surface”.

  The material of the backing metal 14 is not particularly limited, and is, for example, carbon steel or stainless steel.

  FIG. 4 is a plan view showing the back surface of the in-plane gusset joint when the backing metal 14 is fillet welded. The backing metal 14 is attached so that a part thereof protrudes from the end surface of the flange 11. The entire circumference of the backing metal 14 except for the portion protruding from the flange 11 is fillet welded, and the corners are turned and welded. The joint 15 formed by fillet welding joins the back surface of the flange 11 and the end surface of the backing metal 14.

[Process for repair welding the groove]
The groove 11A is repair welded from the other surface of the flange 11 to form the weld metal 16 (FIG. 5) (step S3). FIG. 5 is a perspective view of the in-plane gusset joint when the weld metal 16 is formed. The method of repair welding is not particularly limited, and can be performed by a known method. As shown in FIG. 5, a part of the weld metal 16 may protrude from the end face of the flange 11.

[Process of cutting the backing metal]
The portion where the backing metal 14 protrudes from the end face of the flange 11 is cut (step S4). FIG. 6 is a perspective view of the in-plane gusset joint when the backing metal 14 is cut. At this time, the portion where the weld metal 16 protrudes from the end face of the flange 11 is also cut. This is because if the backing metal 14 or the weld metal 16 protrudes from the end face of the flange 11, stress tends to concentrate on that portion.

[Step of peening the joint]
The joint 15 is peened (step S5). More specifically, the toe 15a (FIG. 4) of the joint 15 is peened over the entire circumference. In addition, the toe 15a of the junction part 15 refers to the part of the line where the junction part 15 and the flange 11 cross.

  Peening is a processing method that gives mechanical repeated impacts to a material. The fatigue strength of the material can be improved by applying compressive stress to the material or correcting the shape by peening. In the present embodiment, the entire circumference of the toe 15a of the joint 15 is peened, and the fatigue strength of the joint 15 is improved. In addition, at least the toe 15a of the joint part 15, that is, the toe 15a on the flange 11 side may be peened, but the part where the joint part 15 and the backing metal 14 intersect, that is, the toe on the backing metal 14 side. 15b (FIG. 4) is also preferably peened.

  For peening according to the present embodiment, for example, UIT (Ultrasonic Impact Treatment), UP (Ultrasonic Peening), UPT (Ultrasonic Peening Treatment) HiFIT (High Frequency Impact Treatment), PIT (Pneumatic Impact Treatment), UNP (Ultrasonic needle peening), peening with an air tool, hammer peening, and the like. Either high-frequency peening or low-frequency peening, and even low-frequency peening has the same effect as high-frequency peening if the shape after processing is equivalent to high-frequency peening. can get.

[Process of peening weld metal]
The weld metal 16 is peened (step S6). More specifically, the toe 16a of the weld metal 16 is peened over the entire circumference. Note that the toe 16a of the weld metal 16 refers to a portion of a line where the weld metal 16 and the flange 11 intersect. By peening the weld metal 16, the fatigue strength of the weld metal 16 can be improved.

  Preferably, the end portion 13b of the welded portion 13 between the flange 11 and the gusset 12 is also peened. As a result, the fatigue strength of the welded portion 13 can be improved.

  The welded structure 100 (FIG. 7) is manufactured by the above process. In the manufacturing method according to the present embodiment, the backing metal 14 is left without being removed. Therefore, the welded structure portion 100 includes a backing metal 14 that is fillet welded to the back surface of the flange 11.

[Configuration of welded structure and effect of this embodiment]
7-9 is a figure which shows the structure of the welding structure 100 manufactured by the manufacturing method by this embodiment. FIG. 7 is a plan view showing the surface of the welded structure 100. 8 is a cross-sectional view taken along line VIII-VIII in FIG. FIG. 9 is a plan view showing the back surface of the welded structure 100.

  The welded structure 100 includes a flange 11, a gusset 12 welded to the end face of the flange 11, a weld metal 16 extending from the end face of the flange 11 to which the gusset 12 is welded, and penetrating the flange 11 in the thickness direction. A backing metal 14 that covers the weld metal 16 with the back surface of the flange 11 and a joint 15 that joins the back surface of the flange 11 and the end surface of the backing metal 14 are provided. The joint 15 is peened.

  In this embodiment, the flange 11 and the backing metal 14 are fillet welded. In other words, the joint 15 that joins the rear surface of the flange 11 and the end surface of the backing metal 14 is formed. Furthermore, the junction 15 is peened. According to this configuration, stress concentration on the boundary portion between the flange 11 and the backing metal 14 is reduced. Further, the backing metal 14 functions as a reinforcing member. Therefore, the fatigue strength of the welded structure 100 can be made higher than when the backing metal 14 is not provided.

  In addition, the presence of the backing metal 14 can improve the reliability of the welded structure 100. That is, it is difficult to obtain sufficient welding quality because welding is performed in a place where it is difficult to work such as a high place, or when the welding quality of the weld metal 16 is not sufficient due to circumstances such as difficulty in checking defects. Even if it exists, by the backing metal 14, generation | occurrence | production of the fatigue crack from a welding root part can be suppressed.

  In the conventional method, when repair welding is performed, the backing metal 14 is temporarily fixed to the repair weld portion, and welding is performed. The temporarily fixed backing metal 14 is integrated with the flange 11 by repair welding. However, if the backing metal 14 is left, stress concentrates on the boundary portion between the flange 11 and the backing metal 14 and the fatigue strength is greatly reduced. Therefore, in the conventional method, it is necessary to grind and remove the backing metal 14 integrated with the flange 11 with a grinder or the like. On the other hand, according to the manufacturing method according to the present embodiment, the backing metal 14 can be left as described above. Since there is no step of grinding the backing metal 14 with a grinder or the like, labor can be greatly reduced.

  In this embodiment, the weld metal 16 is also peened. According to this configuration, the fatigue strength of the welded structure 100 can be further improved.

  The extra height h (FIG. 8) of the weld metal 16 is not particularly limited unless it is negative. The extra height h does not greatly affect the fatigue strength of the welded structure 100. However, since it is not preferable that the extra height h is negative, it is preferable that the extra height h is 1 mm or more with some margin. The extra height h is the height at which the weld metal 16 protrudes from the surface of the flange 11.

  The thickness t (FIG. 8) of the backing metal 14 is not particularly limited. Even when the backing metal 14 is thin, a reinforcing effect can be obtained as compared with the case where the backing metal 14 is not provided. However, if the backing metal 14 is too thin, the weld metal 16 may penetrate the backing metal 14 during repair welding. Therefore, the thickness t of the backing metal 14 is preferably 3 mm or more.

  The thickness t ′ (FIG. 8) of the joint portion 15 is not particularly limited as long as the backing metal 14 is joined to the flange 11. In order to facilitate the transmission of stress to the backing metal 14 via the joint 15, the thickness t ′ of the joint 15 is preferably 3 mm or more. Further, the relationship between the thickness t of the backing metal 14 and the thickness t ′ of the joint 15 is not particularly limited, and the thickness t of the backing metal may be thinner than the thickness t ′ of the joint 15.

  The distance d1 (FIG. 7) between the toe 16a of the weld metal 16 and the end 13b of the welded part 13 after processing is preferably larger than the thickness T (FIG. 8) of the flange 11. If d1 is T or less, the welded portion 13 is affected by the heat of repair welding, and the fatigue strength of the welded structure 100 may be reduced.

  As shown in FIG. 9, in the present embodiment, a part of the joint portion 15 is welded to the welded portion 13 between the flange 11 and the gusset 12 in the direction parallel to the weld line between the flange 11 and the gusset 12 (x direction). overlapping. More specifically, the end 13b of the welded portion 13 after processing overlaps with the joint portion 15 in the x direction. According to this configuration, it is possible to reinforce the end portion 13 b where stress is easily concentrated by the joint portion 15. Therefore, the fatigue strength of the welded structure 100 can be improved.

  In the above, the manufacturing method of the welding structure by the 1st Embodiment of this invention and the structure of the welding structure 100 manufactured by the method were demonstrated.

  Above, the case where the process (step S5) of peening the junction part 15 was implemented after the process (step S4) of cut | disconnecting the backing metal 14 was demonstrated. However, the timing of peening the joint 15 is arbitrary as long as it is after repair welding (step S3). That is, the joint 15 may be peened immediately after repair welding, and then the backing metal 14 may be cut. Moreover, whichever of the peening of the joining part 15 (step S5) and the peening of the weld metal 16 (step S6) may be performed first. In short, the order of step S4 to step S6 is arbitrary.

  In the above description, the case where the backing metal 14 is attached so that a part thereof protrudes from the end face of the flange 11 (FIG. 4), and the protruding part after repair welding has been described. However, the end face of the backing metal 14 and the end face of the flange 11 may be aligned and attached. In this case, the step of cutting the backing metal 14 (step S4) can be omitted.

  The peening (step S6) of the weld metal 16 is an optional process. That is, the peening (step S6) of the weld metal 16 is preferable because it is excellent in obtaining fatigue strength, but it may not be performed.

  In FIGS. 1 to 9, the flange 11 and the gusset 12 are both shown to have a plate shape, but the shapes of the flange 11 and the gusset 12 are arbitrary.

[Modification of First Embodiment]
In the first embodiment, as illustrated in FIG. 9, the configuration has been described in which the end portion 13b of the welded portion 13 after processing overlaps the joint portion 15 in the x direction. The same effect can be obtained when the end portion 13b and the backing metal 14 overlap. FIG. 10 is a plan view showing a back surface of a welded structure 101 which is a modified example of the welded structure 100. Also in this modified example, a part of the joint portion 15 overlaps the weld portion 13 between the flange 11 and the gusset 12 in the x direction. In this modification, the end portion 13b of the welded portion 13 after processing overlaps the joint portion 15 and the backing metal 14 in the x direction. This configuration also reinforces the end portion 13b where stress is easily concentrated. Therefore, the fatigue strength of the welded structure 101 can be improved.

  But the edge part 13b does not need to overlap any of the junction part 15 and the backing metal 14 in the x direction. FIG. 11 is a plan view showing the back surface of a welded structure 102 that is another modification of the welded structure 100. In this modification, the joint portion 15 does not overlap the welded portion 13 between the flange 11 and the gusset 12 in the x direction. In this case, the distance d2 between the toe 15a of the joint 15 and the end 13b of the welded portion 13 is preferably larger than the thickness T (FIG. 8) of the flange 11. This is because if d2 is T or less, the welded portion 13 is affected by the heat of fillet welding, and the fatigue strength of the welded structure 102 may be reduced.

[Second Embodiment]
FIG. 12 is a flowchart showing a method for manufacturing a welded structure according to the second embodiment of the present invention. This manufacturing method includes a step of grinding the weld metal (step S7) instead of the step of peening the weld metal of the first embodiment (step S6 in FIG. 2).

  FIG. 13 is a perspective view of a welded structure 200 manufactured by this manufacturing method. The welded structure 200 includes a weld metal 26 instead of the weld metal 16 (FIG. 8) of the welded structure 100 according to the first embodiment. The weld metal 26 is formed so as to have the same height as the surface of the flange 11 by the grinder process (step S7). According to this configuration, stress is not concentrated on the weld metal 26. Therefore, the fatigue strength of the welded structure 200 can be improved.

  The step of grinding the weld metal 26 (step S7) may be performed before the step of cutting the backing metal 14 (step S4) or the step of peening the joint 15 (step S5). That is, the order of step S4, step S5, and step S6 is arbitrary.

[Third Embodiment]
FIG. 14 is a flowchart showing a method for manufacturing a welded structure according to the third embodiment of the present invention. This embodiment is different from the first embodiment in the following points. In the first embodiment, repair welding was performed after fillet welding of the backing metal (FIG. 2). In contrast, in the present embodiment, the backing metal is temporarily fixed (step S8), repair welding is performed (step S3), and the flange and the backing metal are welded to the fillet (step S2).

  Also by this method, a welded structure having the same configuration as that of the first embodiment can be obtained. Therefore, similarly to the first embodiment, a welded structure having excellent fatigue strength can be obtained.

  In the flow chart of FIG. 14, the step of cutting the backing metal (step S4) is performed after the fillet welding step (step S2), but the fillet welding may be performed after cutting the backing metal. Good. Further, the timing of the step of peening the joint (step S5) is arbitrary as long as it is after the step of fillet welding (step S2). The timing of the step of peening the weld metal (step S6) is also arbitrary as long as it is after repair welding (step S3).

  Also in the present embodiment, the step of peening the weld metal (step S6) may be omitted. Moreover, it may replace with the process (step S6) of peening a weld metal, and may implement the process of grinder-processing the weld metal demonstrated in 2nd Embodiment.

  Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to these examples.

A plurality of in-plane gusset joints for testing were prepared using a rolled steel plate SM490B for welded structure defined in JIS G3106. FIG. 15A is a plan view of a test in-plane gusset joint, and FIG. 15B is a side view. The numerical values in the figure are dimensions (unit: mm). A steel plate having a plate thickness of 16 mm, a width of 100 mm, and a length of 800 mm was used as a flange, and a steel plate having a plate thickness of 9 mm, a width of 60 mm, and a length of 200 mm was used as a gusset. By fillet welding by CO ₂ welding, a gusset was attached to the end of the width at the center of the length of the flange to form an in-plane gusset joint.

  First, fatigue tests were performed on these in-plane gusset joints in order to introduce fatigue cracks. Specifically, using a 50-ton servo-type fatigue testing machine, each in-plane gusset joint was subjected to one-way swing in the axial direction of the material (a nominal stress range of the flange of 100 MPa). The test temperature was room temperature and the test frequency was 10 Hz.

  A welded structure was manufactured from each in-plane gusset joint into which a fatigue crack was introduced, by the method described in the embodiment. As shown in Table 1, ten types of welded structures were produced while changing the processing of the backing metal and the processing of the repair weld.

  In the column of “Processing of backing metal” in Table 1, the processing method of the backing metal of each welded structure is described. No. In 0 and 1, after the repair welding, the backing metal was removed by grinding with a grinder. No. In 2-9, the backing gold was left behind. No. In all of Nos. 2 to 9, the fillet was welded to the flange and the backing metal, and the weld toe was treated with UIT. No. In 2, 3, 5-7, and 9, the thickness of the backing metal is 9 mm. 4 and no. In No. 8, the thickness of the backing metal was 3 mm.

  In the column of “treatment of repair welds” in Table 1, a method for treating weld metal formed by repair welding is described. No. In 0, 2, and 6, the weld metal was ground with a grinder and finished to be flush with the flange. No. In 1, 5, and 9, the extra height of the weld metal (h in FIG. 8) was 1 mm, and the toe was treated with UIT. No. In 3, 4, 7, and 8, the extra height of the weld metal (h in FIG. 8) was set to 2 mm, and the toe was processed with UIT.

  In the column of “position of joint” in Table 1, the positional relationship between the end of the welded portion between the flange and the gusset and the joint between the flange and the backing metal is described. No. In Nos. 2 to 5, the end of the welded portion between the flange and the gusset overlaps with the joint between the flange and the backing metal in a direction parallel to the weld line (see FIG. 9). No. 6 to 9, the end of the welded portion between the flange and the gusset is separated from the joint between the flange and the backing metal by a distance larger than the thickness of the flange in a direction parallel to the weld line (see FIG. 11).

  Fatigue tests were conducted on these welded structures by the same method as used for introducing fatigue cracks, and the fatigue life was evaluated. No. In a welded structure of 0, the fatigue life that was defined as the reference was the time during which fatigue cracks appeared clearly (approximately 20 mm in length). The fatigue life is No. The fatigue life of each welded structure is No. 0 based on the fatigue life of 0. We evaluated how many times it became zero. The results are shown in the column of “Extension of fatigue life” in Table 1.

  As shown in Table 1, no. For the welded structures of Nos. 2 to 9, No. 1 with the backing metal deleted. Compared with the welded structures of 0 and 1, excellent fatigue strength was exhibited.

  No. 2-5 and no. Compared with 6-9, the end of the welded portion between the flange and the gusset overlaps with the joint between the flange and the backing metal in the direction parallel to the weld line. I found out that

  No. 2 and No. No. 3 and No. 3 6 and no. Compared with No. 7, it was found that better fatigue strength can be obtained by treating the toe with UIT while leaving the surplus than grinding the weld metal formed by repair welding. On the other hand, no. 3 and no. No. 5 and no. 7 and no. From the comparison with 9, it can be seen that the extra height does not greatly affect the fatigue strength. No. 3 and no. 4 and No. 4 7 and no. From the comparison with 8, it can be seen that the thickness of the backing metal does not greatly affect the fatigue strength.

  The embodiment of the present invention has been described above. The above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and can be implemented by appropriately modifying the above-described embodiment without departing from the spirit thereof.

Explanation of sign

10 In-plane gusset joint 11 Flange CR Crack 11A Groove 12 Gusset 13 Welded portion 13a, 13b End 14 Backing metal 15 Joint 15a, 15b Toe 16, 26 Weld metal 16a Toe 100, 101, 102, 200 Weld Structure

Claims (7)

A manufacturing method for manufacturing a welded structure by processing a welded joint,
The weld joint includes a first member and a second member welded to an end surface of the first member,
The first member has a crack extending from an end portion of a welded portion with the second member,
The manufacturing method includes:
Forming a groove penetrating the first member in a portion of the first member including the crack;
Forming a joint by fillet welding a backing metal that covers the groove on one surface of the first member;
Repair welding the groove from the other surface of the first member to form a weld metal;
Peening the joint after forming the weld metal,
A method for manufacturing a welded structure, wherein the backing metal is left. It is a manufacturing method of the welded structure according to claim 1,
A method for manufacturing a welded structure, further comprising a step of peening the weld metal. A method for producing a welded structure according to claim 1 or 2,
The method for manufacturing a welded structure, wherein the weld metal protrudes from the other surface of the first member by 1 mm or more. It is a manufacturing method of the welded structure according to claim 1,
A method for manufacturing a welded structure, further comprising a step of grinding the weld metal. A method for producing a welded structure according to any one of claims 1 to 4,
The method for manufacturing a welded structure, wherein the backing metal has a thickness of 3 mm or more. A method for manufacturing a welded structure according to any one of claims 1 to 5,
Manufacture of a welded structure in which a part of the joining portion overlaps with a welded portion between the first member and the second member in a direction parallel to a weld line between the first member and the second member. Method. A first member;
A second member welded to an end face of the first member;
A weld metal extending from the end surface welded to the second member of the first member and penetrating the first member in the thickness direction;
A backing metal that covers the weld metal on one surface of the first member;
A joining portion that joins the one surface of the first member and an end surface of the backing metal;
The welded structure is a peened joint.

Images