KR20120046269A - Out-of-plane gusset welded joint and fabrication method thereof - Google Patents

Abstract

In the manufacturing method of this out-of-plane gusset welding joint provided with a base plate, a gusset plate projecting from the surface of this base plate, and a fillet welding part, one end part of the plate width direction of the edge part of the longitudinal direction of the said gusset plate is plate width w. Cut out in the direction of to form a cutout, arrange the gusset plate on the surface of the base plate, and perform fillet welding so that the predetermined leg length (d ₂ ) on the gusset plate side is not less than the cutout height (a), The leg length d ₂ ′ on the gusset plate side is 1/3 or more of the plate thickness t ₂ of the gusset plate, and the leg length d ₂ ′ and the leg length d on the base plate side. Forming a fillet weld where ₁ '), penetration length x' and penetration angle θ 'satisfy x' + d ₁ '> d ₂ ' / sin θ ', and wherein at least the Bay The impact treatment which improves a fatigue characteristic is performed to the weld toe part on the plate | board side.

Description

Out-of-plane gusset welded joint and its manufacturing method {OUT-OF-PLANE GUSSET WELDED JOINT AND FABRICATION METHOD THEREOF}

The present invention relates to an out-of-plane gusseted welded joint in which two plate members are welded by fillet welding, and a method of manufacturing the same. In particular, the present invention relates to an out-of-plane gusset welded joint having excellent fatigue properties and a method of manufacturing the same.

This application claims priority in August 24, 2009 based on Japanese Patent Application No. 2009-193201 for which it applied to Japan, and uses the content for it here.

In order to reinforce the plate member of the structure or to install the plate member of the structure on another member (for example, another plate member), the plate member of the structure is an accessory hardware, so as to protrude from the plate surface of the plate member. The member is provided by fillet welding, and the out-of-plane gusset welding joint is formed.

When the cyclic stress is applied to the weld joint, for example, a significant stress concentration occurs at the weld end portion, or a tensile residual stress is formed at the weld end portion, so that a fatigue crack is generated from the weld end portion, whereby fatigue characteristics are improved. It is known that it will fall remarkably.

As a countermeasure, conventionally, in order to suppress stress concentration at the weld end portion, for example, a method of increasing the curvature of the edge portion by applying grinder treatment, TIG dressing treatment, makeup padding welding, etc. to the weld edge portion of the weld joint is adopted. come. Moreover, in order to reduce the tensile residual stress of a weld toe part, the method of performing a hit treatment (pinning process), such as a shot peening, a hammer peening, a laser peening, a water jet peening, or a post-weld heat treatment, is used, for example in a weld toe part. Has been.

Recently, a method of applying a blow treatment using ultrasonic vibration (hereinafter sometimes referred to as UIT treatment (Ultrasonic Impact Treatment)) is introduced to introduce a compressive residual stress to the weld edge or to improve the shape of the weld edge. It is.

For example, in Patent Document 1, in order to improve the fatigue characteristics of a material by the introduction of compressive residual stress, a plurality of sets of working tables by ultrasonic blow treatment are applied on the surface of the material perpendicular to the direction in which the fatigue characteristics are to be improved. The method of forming and forming three or more edges in the direction orthogonal to at least a processing stand among these working tables is disclosed. Further, in Patent Document 2, a groove having a radius of curvature R of at least 2 mm and a width of at least 1 mm is formed in the vicinity of the weld end portion by using an ultrasonic striking treatment device to improve the fatigue strength of the weld portion. A method of forming a sugar strike density of 11 times / mm or more is disclosed. In addition, Patent Document 3 discloses a blow treatment apparatus and a blow treatment method using ultrasonic waves.

7A to 7D are perspective schematic diagrams illustrating the manufacturing procedure of a conventional out-of-plane gusset welded joint, showing a situation near the turning weld 110 of the out-of-plane gusseted weld joint 101.

The gusset plate 103 is fillet welded to the base plate 102 (FIGS. 7A to 7B), and the weld ends 107 and 107 ′ are formed in the fillet weld 109.

As shown in FIGS. 7C to 7D, the impact treatment is applied to the weld short end portion 107 of the torsion welding portion 110 among the fillet welds 109 to form the impact treatment mark 111. 7A to 7D show a state where the hitting treatment is performed on the weld toe portion 107 on the base plate 102 side.

Japanese Patent Application Laid-Open No. 2006-167724 Japanese Patent Application Publication No. 2006-175512 US Patent No. 6,171,415

By applying a hit treatment to the weld end of the out-of-plane gusset weld joint as described above, the shape of the weld end is made into a smooth (curve) shape where stress is hard to concentrate, and the tensile residual stress in the weld end and its vicinity is alleviated. The compressive residual stress is imparted. As a result, generation | occurrence | production of a crack from a weld toe part and its vicinity can be prevented, and a fatigue characteristic can be improved. In such a method, the reduction of the fatigue life due to the occurrence of fatigue cracks from the weld edge is greatly suppressed, and the fatigue characteristics are significantly improved. However, in the out-of-plane gusset welding joint by fillet welding, there is a limit to the improvement of the fatigue characteristics. there was.

MEANS TO SOLVE THE PROBLEM In order to further improve the fatigue characteristic of an out-of-plane gusset welding joint, the present inventors performed the ultrasonic shock treatment to the weld toe part of the turning welding part of an out-of-plane gusset welding joint, and examined the fatigue life. As a result, it has been found that many fatigue cracks are generated from the weld route, which hinders the improvement of the fatigue characteristics. That is, since the occurrence of the crack from the weld edge is suppressed by the blow treatment to the weld edge, fatigue cracks are generated and developed from the weld root portion where fatigue cracks tend to occur after the weld edge, and fatigue of the out-of-plane gusset is caused. It was found that it affects the lifespan.

As for the generation of the fatigue crack from the weld root portion of the fillet welded portion, when the weld portion of the fillet welded portion is a welded portion of full penetration, it is obvious that the weld root portion is eliminated, so that the fatigue characteristic is improved. However, in the case of performing full penetration welding, it is necessary to perform a beveling process over a wide range, it takes a long time for welding work, and it is difficult to restrain the gusset plate at the time of tack welding the gusset plate. Therefore, the burden of welding work is large and cost increases.

SUMMARY OF THE INVENTION In view of the above situation, an object of the present invention is to provide a weld joint and a method of manufacturing the same in an out-of-plane gusset welded joint in which a blow treatment is applied to the weld end to improve fatigue characteristics. do.

The present inventors examined an efficient method for releasing stress concentration to the weld root portion.

6A and 6B are cross-sectional schematic diagrams illustrating stress concentration of the out-of-plane gusseted weld joint 1 to the turning welded portion 10 when cyclic stress is applied. The present inventors show the position of the welding root part 8 as shown in FIG. 6A in the conventional position C shown in FIG. 6B (the longitudinal direction edge part of the base plate 2 side of the gusset plate 3). It was found that the fatigue characteristics can be improved by moving from] to the position B inside the gusset plate 3 from this position C and controlling the leg length of the fillet welding. That is, as shown in FIG. 6A, by controlling the leg length of fillet welding, the steepness of the stress dispersion path is alleviated, stress concentration to the welding root 8 is avoided, and the throat thickness is effectively increased. Therefore, crack generation in the welding root part 8 and the throat thickness part can be suppressed. Therefore, the effect of the impact treatment on the weld toe portion can be sufficiently exhibited, and the fatigue characteristic can be further improved. MEANS TO SOLVE THE PROBLEM The present inventors came to this invention as a result of the above-mentioned examination.

That is, the summary of this invention is as follows.

(1) The manufacturing method of the out-of-plane gusset welding joint which concerns on one form of this invention is a manufacturing method of the out-of-plane gusset welding joint provided with a base plate, a gusset plate, and a fillet welding part which protrude from the surface of this base plate, The said gusset One end in the plate width direction of the end portion in the longitudinal direction of the plate is cut out in the direction of the plate width w, and a cutout portion having a cutout height a, a cutout length x and a cutout angle θ of 80 ° or less And the gusset plate is disposed so that the end face in the direction of the plate width w of the gusset plate having the cutout faces the surface of the base plate, and thus the predetermined leg length d ₂ on the gusset plate side. ), and that the cut-out height (a) is performed such that the fillet welding as described above, the gusset plate side leg length (d ₂ ') of the, at least one-third of the plate thickness (t ₂₎ of the gusset plate, A bridge length (d ₂ ') and the side leg of the base plate (d _1') and the penetration length (x ') and the penetration angle (θ') is _{x '+ d 1'> d} 2 '/ sinθ' The said fillet welding part which satisfy | fills is formed, and the hitting process which improves a fatigue characteristic at least in the weld toe part of the said base plate side of a turning welding part is performed among the said fillet welding parts.

(2) In the manufacturing method of the out-of-plane gusset welding joint as described in said (1), the said notch angle (theta) may be 45 degrees or more and 75 degrees or less.

(3) The out-of-plane gusseted welded joint according to one embodiment of the present invention includes a base plate, a gusset plate projecting from the surface of the base plate, and a fillet welded portion, and in the fillet welded portion, the leg length on the gusseted plate side ( d ₂ ′ is 1/3 or more of the thickness t ₂ of the gusset plate, the leg length d ₂ ′, the leg length d ₁ ′ on the side of the base plate, and the penetration length x ') And penetration angle [theta]' satisfy x '+ d ₁ '> d ₂ '/ sinθ', and at least one of the fillet welds is provided with a strike mark on the welded end portion of the base welded portion of the turning welded portion. It is.

(4) In the out-of-plane gusset welding joint as described in said (3), the said penetration angle (theta) 'may be 30 degrees or more and 75 degrees or less.

However, at the end of the cross section in the longitudinal direction of the gusset plate, the penetration length x 'is the weld root portion (from the point C' which is the starting point of the waterline lowered from the weld ground end portion 7 'on the gusset plate side to the base plate). 8) length. The penetration angle θ 'is an angle formed by line segment 7'8 and line segment 8C'. Further, the cutout height a is the height from the surface of the base plate to the cutout position A of the cutout portion of the gusset plate. The notch length x is the edge part of the longitudinal direction at the base plate side in the gusset plate after forming a notch from the corner C of the longitudinal direction edge part of the base plate side in a gusset plate before forming a notch. Is the length up to the position (B). The notch angle θ is an angle formed by the line segment AB and the line segment BC of the notched portion.

In the weld joint obtained by notching the corner part of the base plate side of the longitudinal end surface of a gusset plate, forming a notch in a gusset plate, and fillet-welding this gusset plate to a base plate, a weld root part cuts off a gusset plate. It is possible to reliably penetrate larger in the longitudinal direction of the gusset plate than the weld route in the case of not forming, thereby increasing the throat thickness. Moreover, in this weld joint, since the leg length is adjusted according to the position of a welding root part, the throat thickness is compared with the case where fillet welding is performed with the leg length on the gusset plate side, and the leg length on the base plate side in the same length. I can make it big.

Thus, since the throat thickness can be increased by approximately 25% or more as compared with the conventional weld joint, as shown in Fig. 6A, the concentration of stress in the welding portion is alleviated, and the fatigue breakage from the weld root portion is prevented. In this way, it is possible to significantly improve the fatigue strength of the turning welding portion of the out-of-plane gusset welding joint.

1: is AA partial sectional drawing of FIG. 4B which shows typically the out-of-plane gusset welding joint after welding in one Embodiment of this invention.
FIG. 2: is BB partial sectional drawing of FIG. 4D which shows typically the out-of-plane gusset welding joint after the striking process in this embodiment.
3 is a partial cross-sectional view showing another embodiment of the out-of-plane gusseted welded joint in the present embodiment.
It is a perspective schematic diagram which shows the manufacturing procedure of the out-of-plane gusset welding joint in this embodiment.
It is a perspective schematic diagram which shows the manufacturing procedure of the out-of-plane gusset welding joint in this embodiment.
It is a perspective schematic diagram which shows the manufacturing procedure of the out-of-plane gusset welding joint in this embodiment.
It is a perspective schematic diagram which shows the manufacturing procedure of the out-of-plane gusset welding joint in this embodiment.
It is a perspective schematic diagram which shows another form of the gusset plate of the out-of-plane gusset welding joint in this embodiment.
FIG. 6A is a cross-sectional schematic diagram illustrating a concentration state of stress in a turning welding part of an out-of-plane gusset welded joint when a cyclic stress is applied in the present embodiment. FIG.
It is a cross-sectional schematic diagram explaining the concentration situation of the stress in the turning welding part of the out-of-plane gusset welding joint when a cyclic stress is applied.
It is a cross-sectional schematic diagram explaining the concentration situation of the stress in the turning welding part of the out-of-plane gusset welding joint when a cyclic stress is applied.
It is a perspective schematic diagram which shows the manufacturing procedure of the conventional out-of-plane gusset welding joint.
It is a perspective schematic diagram which shows the manufacturing procedure of the conventional out-of-plane gusset welding joint.
It is a perspective schematic diagram which shows the manufacturing procedure of the conventional out-of-plane gusset welding joint.
It is a perspective schematic diagram which shows the manufacturing procedure of the conventional out-of-plane gusset welding joint.
8 is a schematic cross-sectional view showing the throat thickness and the position of the throat thickness.

Hereinafter, the present invention will be described in detail.

FIG. 1: is a schematic diagram which shows the longitudinal cross section of the gusset plate 3 of the out-of-plane gusset welding joint 1 in FIG. 4B, ie, AA cross section of FIG. 4B, and hits the welding edge part 7 with a welding process. The state before doing so is shown. FIG. 2: is a schematic diagram which shows the B-B cross section of FIG. 4D, and has shown the state in which the hit process mark was formed by performing the hit process to the weld toe part 7. FIG.

In one Embodiment of this invention, in order to improve the fatigue characteristic of a weld joint, the notch part is formed in the corner part of a gusset plate, ensuring a large throat thickness, and reducing the concentration of cyclic stress to a weld root part. That is, as can be seen from Figs. 6A and 6B, the throat thickness becomes large. In addition, throat thickness is defined in JIS Z 3001 as the distance from the root (welding root part 8) of the cross section of a fillet welding to the surface, and is the distance t in FIG. Therefore, the shortest distance from the welding root part 8 to the welding metal surface is welded depending on the position of the welding edge portions 7 and 7 'where the weld metal surface and the base material surface intersect, and the penetration shape of the weld metal. The distance between the root portion 8 and the weld end portion 7 or the distance between the weld root portion 8 and the weld edge portion 7 'may be set. That is, the point 13 (end point of throat thickness) on the surface of the weld metal 5 having the minimum distance from the weld root 8 to the surface of the weld metal 5 is the weld edge 7 or the weld edge. It may coincide with part 7 '.

In FIG. 1 and FIG. 2, each point and each dimension in the weld metal 5 are defined as follows. The position of the welded edge 7 on the side of the base plate 2 is point 7, and the position of the welded edge 7 'on the gusseted plate 3 side is 7'. 8, the foot of the waterline which fell from the welding edge part 7 'of the gusset plate 3 side to the surface (line segment 78) of the base plate 2 before welding is defined as point C'. Further, the angle formed by the penetration length x '(mm), the line segment 7'8 and the line segment 8C' is determined by the distance between the welding root portion 8 and the point C 'after welding. , The length of the line segment 7C 'is the leg length (d ₁ ') (mm) at the base plate 2 side, and the size of the line segment 7'C 'is the leg length (d ₂ ') (mm) at the gusset plate 3 side. Defined as The leg length is defined as the distance from the point C 'to the end of the fillet welding (welding ends 7, 7'). As described later, the gusset plate 3 in which the cutout portion 4 was formed by changing conditions such as welding conditions and leg lengths is fillet welded to the base plate 2, and the weld joint 1 as shown in FIG. ) Was produced. After the ultrasonic impact treatment was performed on the weld end 7 'of the turning weld 10 of the weld joint 1, the fatigue characteristics of the weld joint 1 as shown in Fig. 2 were examined by a fatigue test. . Further, the base plate (2) side leg length _{(d 1 ') (㎜)} , the gusset plate (3) side leg length (d ₂ a'), (㎜), penetration angle (θ ') (°), the penetration length of the The relationship between each of (x ') (mm) and fatigue characteristics was investigated. In addition, the turning welding part 10 consists of the welding part formed by the turning welding, and the welding part formed in the end surface of the gusset plate in the longitudinal direction.

As a result, in the weld joint 1 obtained by forming the notch 4 in the gusset plate 3 and performing welding, the throat thickness can be made larger than the weld joint in which the notch is not formed in the gusset plate. It was found that the fatigue characteristics were excellent. However, when the leg length d ₁ ′ is small, the end point (point 13 in FIG. 8) of the throat thickness portion (the portion where the welding metal 5 is the thinnest) is the most fatigued from the gusset plate 3 side. It may be biased by the weld toe part 7 on the side of the base plate 2 which may generate | occur | produce a crack. Accordingly, It is from the viewpoint of improving the fatigue property of the base plate (2) welded on the side of Gdansk portion 7, the reduced leg length (d ₁ ') has been found that undesirable.

Thus, in the present embodiment, the position of the penetration length (x ') and the bridge length (d _1') are, to the welding of the equation (1) side of the base plate (2), so as to satisfy after welding Zidane section 7 And minimum penetration rates. As a result, it is possible to avoid the end point 13 of the throat thickness portion from becoming the weld toe portion 7 on the side of the base plate 2, thereby ensuring excellent fatigue characteristics.

In addition, the penetration length (x ') and the bridge length (d _1') is or may even satisfies the following equation (2).

Further, the deeper the penetration (movement of the melting line 6 into the gusset plate 3) into the gusset plate 3, the smaller the penetration angle [theta] 'becomes, which is suitable in terms of securing the throat thickness. Do. However, for example, it takes a long time for improvement work required in advance, a plurality of welding passes are required to secure penetration, or labor is required for restraint of a member before welding, so that the welding work time becomes long. Therefore, it is preferable that penetration angle (theta) 'is 35 degrees-60 degrees. In addition, "in the case of more than the 75 °, the penetration length (x penetration angle (θ)") is therefore small, and it is necessary to increase the bridge length (d ₂ ') in order to secure a sufficiently large throat thickness, It takes effort by welding work such as multilayer padding.

In order to further improve the fatigue characteristics of the out-of-plane gusseted welded joint, the inventors investigated the influence of the leg length in the welded joint provided with the gusseted plate with the cutout. That is, using the gusset plate with the cutout, the weld leg length d ₂ ′ on the gusset plate side is 5 times the plate thickness t ₂ from 1/3 times the plate thickness t ₂ of the gusset plate. The weld joint was produced by performing a fillet welding by changing between / 7 times. Moreover, in order to satisfy Formula (1), penetration angle (theta) 'was changed between 30 degrees-75 degrees, and the leg length (d ₁ ') of the base plate side was made substantially constant. After the ultrasonic impact treatment for improving the fatigue characteristics at the welded end portions of the welded joints of the welded joints thus manufactured, the fatigue characteristics of the welded joints were examined by a fatigue test.

As a result, in the weld joint using the gusset plate in which the notch is formed, if the leg length on the gusset plate side is small, a large stress flows to the throat thickness portion as shown in Fig. 6C, and the gusset plate 3 side A fatigue crack may generate | occur | produce from the welding edge part 7 'vicinity, or a fatigue crack may generate | occur | produce from the welding root part 8, and may penetrate the weld metal 5. Therefore, it turned out that it is not desirable to make the leg length on the gusset plate side small from the point which improves a fatigue characteristic. For this reason, as a result of further examining the leg length on the gusset plate side, in order to reduce the stress flowing through the throat thickness portion of the weld metal, the leg length d ₂ ′ on the gusset plate side is determined by the thickness of the gusset plate (t _2). By setting it as 1/3 or more of), it turned out that a fatigue characteristic improves significantly.

Thus, in this embodiment, the length of the leg gusset plate side (d ₂ ') is at least one-third of the thickness of the gusset plate (t _2). In the out-of-plane gusset welding joint of this embodiment, the stress concentration in the throat thickness portion can be alleviated by determining the leg length on the gusset plate side by the plate thickness of the gusset plate. Therefore, the improvement effect of the fatigue characteristic by the hitting process to the weld toe part 7 is exhibited effectively, and the fatigue characteristic of a weld joint can be improved significantly. In addition, taking into account the dimensions of the gusset plate, the leg length d ₂ ′ is equal to or less than the plate width w of the gusset plate.

In the out-of-plane gusset welding joint of the present embodiment, as described above, the relationship between the leg length d ₂ ′ on the gusset plate side and the plate thickness t ₂ of the gusset plate is defined, and the penetration length x 'and , The relationship between the penetration angle θ ', the leg length d ₁ ′ on the base plate side, and the leg length d ₂ ′ on the gusset plate side is defined by equation (1). By these relationships, the throat thickness of the weld portion is sufficiently secured, and the stress concentration in the throat thickness portion is alleviated. Moreover, the ultrasonic shock treatment for improving a fatigue characteristic is performed to the weld toe part of a torsion welding part, and the fatigue characteristic is improved. In addition, in order to reduce stress concentration, it is effective to increase the leg length d ₁ ′ on the base plate side or to smoothly finish the shape of the weld end portion 7 in advance.

Below, the efficient manufacturing method of the out-of-plane gusset welding joint which concerns on one Embodiment of this invention is demonstrated.

4A to 4D are partial perspective views schematically illustrating the procedure of the manufacturing method of the out-of-plane gusset welded joint of the present embodiment. The out-of-plane gusseted weld joint 1 is a base plate 2 (plate thickness t ₁ (mm)) and a gusset plate 3 (plate thickness t ₂ ) (fillet welded on the surface of the base plate ₂ ). Mm)]. In addition, the direction (direction of the plate thickness t ₁ of the base plate 2) perpendicular to the surface of the base plate 2 and the direction (height direction) of the plate width w of the gusset plate 3 coincide with each other. Doing. Further, the direction orthogonal to the direction of the plate width w of the gusset plate 3 and the direction of the plate thickness t ₂ is the longitudinal direction of the gusset plate 3. The portion including the side (corner) of the plate thickness (t ₂₎ in the same direction at the end face of the longitudinal direction is a corner of the gusset plate (3).

In the out-of-plane gusset welding joint of the present embodiment, the rectangular gusset plate 3 has a cutout portion in which corner portions (each corner portion) on the side of the base plate 2 are cut out in the height (plate width w) direction ( 4) is formed (FIG. 4A). The cutout portion 4 is a (mm) in the height direction of the gusset plate 3 (in the plate width w direction of the gusset plate 3) from the corner portion of the gusset plate 3 opposite the base plate 2. ) And also the dimension of x (mm) in the longitudinal direction of the gusset plate 3 (direction toward the center of the longitudinal direction of the gusset plate 3) from the corner of the gusset plate 3 opposite the base plate 2. Has

The gusset plate is arranged on the base plate 2 such that the end face in the direction of the plate width w of the gusset plate 3 with the cutout 4 and the surface of the base plate 2 face each other. Thereafter, the gusset plate 3 having the cutout 4 is fillet welded to the base plate 2. As a result, the fillet welding part 9 is formed in the circumference | surroundings (near 4 sides) of the surface in which the gusset plate 3 opposes the base plate 2, and the length of the gusset plate 3 among these fillet welding parts 9 is formed. A turning weld 10 is formed around the end of the direction (the end of the right side of the gusset plate 3 shown in FIG. 4B) (FIG. 4B). Of the fillet welds 9 formed in this manner, at least in the vicinity of the weld ends 7, 7 ′ of the torsion weld 10, for example, by the ultrasonic impact treatment apparatus 12, a blow treatment for improving fatigue characteristics. (FIG. 4C). As a result, the impact treatment mark 11 is formed in the weld toe portions 7 and 7 '(FIG. 4D).

As shown in Figs. 4A to 4D, the out-of-plane gusset welded joint generally has a shape t in which the length in the height direction (plate width w) of the gusset plate is equal to or greater than the length in the thickness direction (plate thickness t ₂ ). ₂ <= w) in many cases. That is, the gusset plate is disposed so that the end face in the plate thickness direction faces the plate face of the base plate, and the circumference (four sides) of the end face is fillet welded to the base plate to have a shape as shown in FIGS. 4A to 4D. An out-of-plane gusseted weld joint is formed. Therefore, the out-of-plane gusset welding joint of the shape as shown to FIG. 4A-FIG. 4D is demonstrated as an example.

In the embodiment, the present invention is not limited to the shape of the gusset plate has a shape (t ₂ ≤w) as shown in Figure 4a to Figure 4d. For example, the shape of the gusset plate may be a shape t ₂ > w as shown in FIG. 5. That is, it may be the length of the height direction of the gusset plate - plate width (w)] is smaller than the length of the shape in the sheet thickness direction [plate thickness (t _2)].

Further, the turning welding portion is formed at the corner portion (four corners of the end face in the plate thickness direction) of the gusset plate having the cutout portion. Here, in order to simplify description, it demonstrates taking the turning welding part provided in the edge part of the gusset plate in the longitudinal direction as an example.

FIG. 1 shows a longitudinal section in the longitudinal direction of the gusset plate 3 of the out-of-plane gusseted weld joint 1 in FIG. 4B. That is, FIG. 1: is a schematic diagram which shows the A-A cross section of FIG. 4B, and has shown the state before performing the hit process to the weld toe part 7. As shown in FIG. FIG. 2: is a schematic diagram which shows the B-B cross section of FIG. 4D, Comprising: The impact processing trace 11 after the impact treatment which improves a fatigue characteristic to the weld edge part 7 is formed.

As shown in FIG. 1 and FIG. 4B, the corner portion on the side of the base plate 2 is cut out and cut out of the corner portion of the end portion in the longitudinal direction of the gusset plate 3 (the end portion at which the welding weld 10 is formed). (4) is formed. This notch part 4 is formed in order to enlarge the area joined by the welding metal 5, and to ensure the throat thickness fully.

In FIG. 1, each point and each dimension in the notch 4 before fillet welding are defined. The corner | corner on the side of the base plate 2 of the edge part of the longitudinal direction of the square gusset plate 3 before a notch is defined as the corner C. As shown in FIG. Further, the position of the end face in the longitudinal direction of the gusset plate 3 spaced apart from the surface of the base plate 2 on the gusset plate 3 side in the height direction of the base plate 2 in the cutout height a (mm) is shown. Defined by position (A). That is, the position A in FIG. 1 is a position spaced apart from the corner C in the width w direction of the gusset plate 3 (the height direction of the base plate 2) by the notch height a (mm). to be. Further, the cut length x from the corner C of the gusset plate 3 to the inner side of the gusset plate 3 (the direction from the end of the gusset plate 3 toward the center of the longitudinal direction of the gusset plate 3) ( Mm) A spaced position is defined as a position B. In addition, the foot of the waterline which fell from the position A to the surface (line segment 78) of the base plate 2 before welding is defined as point C ". The distance between this point C" and the position B is In Fig. 1, the range of triangles surrounded by the position A, the position B and the corner C is cut in the sheet thickness direction to form the cut portion 4. In Fig. 1, the notch length x coincides with the apparent notch length x ".

Here, in FIG. 1 and FIG. 2, the corner C and the point C 'coincide. That is, the foot of the waterline which fell from the notch position A to the surface (line segment 78) of the base plate 2 before welding, and the base plate 2 of the base plate 2 before welding from the branch end 7 'of the gusset plate 3 side. The foot of the waterline lowered to the surface (line segment 78) is shown in the same position, superimposed. In this case, the end surface of the gusset plate 3 in the longitudinal direction is orthogonal to the upper surface of the base plate 2.

In addition, there may be a case in which these two are not orthogonal. For example, in the partial sectional view of the weld joint shown typically in FIG. 3, the shape of the gusset plate 3 before a notch differs from the shape shown in FIG. Thus, in the case of a trapezoidal gusset plate as shown in FIG. 3, the position of the corner C and the point C 'differ. In addition, the notch length x in FIG. 3 becomes longer by the distance between the corner C and the point C "compared with the notch length x in FIG. 1. In the following, the out-of-plane gusset weld joint of FIG. The case of 1) will be described as an example, and in the case of fillet welding of the scallop portion, the notch length x is shortened by the distance between the corner C and the point C ".

This cutout height a (length from position A to corner C) needs to be set to be equal to or less than a predetermined leg length d ₂ on the gusset plate 3 side of the weld joint 1. When the notch height a exceeds the predetermined leg length d ₂ , there is a possibility that the notched part not covered with the welding metal 5 remains in the turning weld part on the gusset plate 3 side, and a healthy weld part may not be obtained. . In addition, since the notch 4 should just be formed in the gusset plate 3, the lower limit of notch height a is not specifically defined. However, when the notch height a is too small, the area joined by welding becomes small, and the effect which suppresses generation | occurrence | production of a fatigue crack falls. In the general case where welding of the gusset plate 3 is performed in three passes or less, it is preferable that the notch height a is 80 to 90% of the predetermined leg length d ₂ on the gusset plate 3 side.

That is, the relationship between the notch height a and the predetermined leg length d ₂ needs to satisfy the following formula (3), and preferably the following formula (4).

Further, the relationship between the cutout height a and the leg length d ₂ ′ on the gusset plate 3 side satisfies the following expression (5).

In addition, the predetermined leg lengths d ₁ and d ₂ are target leg lengths at the time of fillet welding.

On the other hand, as shown in FIG. 1, the angle formed by the line segment AB and the line segment BC is defined as the notch angle θ. This cut angle θ is an angle between the cut surface S of the cutout portion 4 of the gusset plate 3 and the surface of the base plate 2 before welding (the line segment forming the cut surface and the base plate before welding). Angle formed by the line segments forming the upper surface). Since the relationship between the cutout angle θ, the cutout length x, and the cutout height a satisfies the following expression (6), the following expression (8) is derived from the following expression (7).

Therefore, it is necessary to set the dimensions (cut length x and cut angle θ) of the cutout portion 4 so as to satisfy the above expression (8). However, considering the case of Fig. 3, the apparent cut length x " and the cut angle θ need to satisfy the following expression (9).

The notch length x (mm) (or the apparent notch length x ") should just satisfy | fill the said relationship, and is not specifically prescribed. However, if the notch length x becomes too long, the notch angle (theta) As a result, the gap between the line segment AB and the portion surrounded by the line segment BC is particularly narrow in the vicinity of the position B, which makes it difficult to send a welding material such as a welding wire or a welding rod during welding. In this case, the weld metal is not sufficiently delivered to the position B, and there is a possibility that welding defects such as insufficient filling of the weld metal and insufficient penetration are likely to occur.

In addition, when the notch angle (theta) becomes large, the notch length x becomes short and the surface area of a notch part becomes small. Therefore, the effect of the notch part 4 which enlarges the area joined by welding and reduces the stress which arises in a root part becomes small.

Therefore, in order to enlarge the area joined by welding, in the range which x satisfy | fills the said Formula (1), a notch angle (theta) and a notch length (x) so that a weld area may be largely secured and a notch area may be secured. Select.

In addition, it is preferable that the leg length d ₁ ′ is as large as possible in order to reduce the stress concentration of the weld end 7. In addition, the weld ends 7 and 7 'are preferably welded as smoothly as possible in order to facilitate the subsequent ultrasonic striking treatment.

The present inventors prepared various gusset plates in which cutouts were formed so that at least one condition among cutout height a, cutout angle θ, and cutout length x was different, the fillet having a predetermined predetermined leg length d ₂ was prepared. The weld joint was produced by welding. After the ultrasonic striking treatment was performed on the weld edge of the welded portion of the weld joint, the fatigue characteristics were examined by a fatigue test. As a result, the notch angle (theta) was 80 degrees or less, and the fatigue characteristic of the weld joint could be improved reliably. Therefore, the notch angle (theta) of a notch part is 80 degrees or less. In addition, the minimum of cutout angle (theta) is not specifically limited. When the notch angle (theta) is 45 degrees or more, since the clearance gap (gap of notch) between a base plate and a gusset plate was enough, the welding wire could be reached reliably to a welding route part. In this case, sufficient penetration could be obtained efficiently and stably in a comparatively short time. Moreover, when notch angle (theta) is 75 degrees or less, the notch length x and throat thickness can be ensured enough. In this case, the fatigue property of a weld joint fully improved. Therefore, it is preferable that cutout angle (theta) is 45 degrees or more and 75 degrees or less. More preferably, this notch angle (theta) is 50 degrees or more and 70 degrees or less.

As described above, by forming a cutout at the end portion in the longitudinal direction of the gusset plate subjected to the turning welding and fillet welding, the weld root portion of the fillet welding can be spaced apart from the weld end portion, as compared with the case where no cutout is formed. Lot thickness can be increased. As a result, it is possible to alleviate the concentration of the force flow due to the cyclic stress in the weld root portion, and improve the fatigue property of the weld joint (see FIG. 6A). As mentioned above, welding is normally performed while ensuring sufficient penetration so that welding defects, such as insufficient penetration, may not arise in a fillet welding part. Also in this embodiment, welding is performed, ensuring sufficient penetration so that welding defects, such as a penetration shortage, may not generate | occur | produce in the part containing position B (refer FIG. 1, FIG. 2) which is a welding route part.

As described above, the leg lengths d ₁ ′, d ₂ ′ and the penetration angle θ are such that the penetration length x 'and the leg length d ₁ ′ on the base plate side satisfy the above expression ( ₁ ). The welding is carried out in consideration of '). As a result, the minimum penetration amount can be ensured in the weld toe part on the base plate side after welding. Therefore, the thinnest part of the throat thickness can be avoided to be the end portion of the base plate side, and excellent fatigue characteristics can be secured.

Further, the leg lengths d ₁ ′, d ₂ ′ satisfy the following equations (10) and (11) for the predetermined leg lengths (d ₁ , d ₂ ), respectively.

By forming a notch as mentioned above, it becomes possible to manufacture the weld joint which satisfy | fills said Formula (1) efficiently.

In order to further improve the fatigue characteristics of the out-of-plane gusset welded joint as described above, the inventors have used the gusset plate having the cutout to influence the influence of the leg lengths d ₁ ′, d ₂ ′ in the fillet welds. Investigate. As a result, when the leg length d ₂ ′ on the gusset plate side is small, the throat thickness decreases with respect to the plate thickness t ₂ of the gusset plate, so that the stress at the throat thickness portion is found to be high. In addition, it was found that the fatigue property of the weld joint is greatly improved by setting the leg length d ₂ ′ on the gusset plate side to 1/3 or more of the plate thickness t ₂ of the gusset plate.

For this reason, in the manufacturing method of the weld joint of this embodiment, the leg length d ₂ ′ on the gusset plate side is equal to or greater than 1/3 of the plate thickness t ₂ of the gusset plate (Equation 12 below). Weld. By controlling the relationship between the leg length d ₂ ′ on the gusset plate side and the plate thickness t ₂ of the gusset plate, a more sufficient throat thickness can be ensured, thereby reducing the stress generated at the weld root portion, Fatigue properties can be significantly improved.

In normal welding, the leg length d ₁ ′ on the base plate side and the leg length d ₂ ′ on the gusset plate side are often substantially equal lengths. However, the leg length d ₁ ′ on the base plate side satisfies Equation 1 described above, and the leg length d ₂ ′ on the gusset plate side satisfies Equation 1 and Equation 12 above. There is.

As described above, in, the gusset to form the desired cut-out in the plate, the plate thickness of the gusset plate leg gusset plate side (d ₂ ') in the production method of this embodiment of the out-of-plane gusset welded joint (t ₂ Fillet welding is performed while obtaining sufficient penetration so that it becomes 1/3 or more of () and satisfy | fills Formula (1).

Moreover, it is preferable to form a notch so that the notch angle (theta) of a gusset plate may be 45 degree or more and 75 degrees or less. Moreover, it is preferable to obtain the fillet weld part whose penetration angle (theta) 'is 30 degrees or more and 75 degrees or less by welding so that sufficient penetration may be obtained.

Thus, by forming a notch in a gusset plate and welding while ensuring sufficient penetration, the cross-sectional area of each member joined by the weld metal increases, and the throat thickness can be largely secured. Therefore, the stress which generate | occur | produces in a welding root part can be reduced, and the fatigue characteristic of a weld joint can be improved significantly.

Next, in the weld joint of the present embodiment, at least the weld end portion of the turning weld portion among the fillet welds formed as described above is subjected to a blow treatment to improve the fatigue characteristics of the weld edge portion itself.

This striking treatment needs to be carried out at least on the weld toe portion on the base plate side of the torsion welded portion that is prone to fatigue cracking when cyclic stress is applied. However, the impact treatment may be applied to all the weld ends of the turning welded portion or the fillet welded portion.

The blow treatment for improving the fatigue characteristics may be a peening treatment such as shot peening or hammer peening. The method of this hitting process is not specifically limited. That is, it is only necessary to hit the weld end portion to the extent that the position of the edge line of the weld edge portion before the striking treatment cannot be discriminated, to form a smooth valley portion in the weld edge portion, and to provide a compressive residual stress by plastic flow.

However, the hitting treatment (UIT treatment) by the ultrasonic impact treatment apparatus is preferable because it is efficient. The conditions of this UIT impact treatment to a weld toe part are not specifically limited. In this case, it is preferable to perform an appropriate UIT impact treatment in accordance with the fatigue characteristics required for the material (member).

Below, the case where a hit process is performed by an ultrasonic impact apparatus (UIT process) is illustrated. In the striking treatment, the radius of curvature r in the cross section perpendicular to the weld line of the weld edge is 1.0 mm or more and 10.0 mm or less, and the depth f in the thickness direction of the steel material from the steel (base plate or gusset plate) surface is determined. It is preferable to form the ultrasonic impact trace 11 which is 0.05 mm or more and 1.0 mm or less. More preferably, this depth f is 0.1 mm or more and 0.4 mm or less.

When the radius of curvature r of the impact treatment mark 11 (ultrasound impact mark) 11 is 1.0 mm or more, stress concentration to the fillet weld can be sufficiently relaxed. Moreover, when this radius of curvature r is 10.0 mm or less, the effect of relieving stress concentration increases with the increase of the radius of curvature r. In this case, the fatigue resistance of the weld joint can be further improved. This radius of curvature r can be appropriately determined in consideration of the processing time. In addition, the striking process mark (ultrasound impact mark) 11 is normally formed centering on the welding edge parts 7 and 7 '. However, it is preferable that the hit treatment mark (ultrasound impact mark) 11 is formed to include at least a part of the weld metal 5 and the weld heat affected zone. Therefore, it is preferable to select the ultrasonic impact position and the curvature radius r of the ultrasonic impact trace in consideration of the position at which the impact treatment trace 11 is formed.

In addition, when the depth f of the hit treatment mark (ultrasound impact mark) 11 to the base plate 2 or the gusset plate 3 is 1.0 mm or less, the weld edge portion (with the increase of the depth f) is increased. 7) The effect of releasing tensile residual stress in the vicinity or giving compressive residual stress increases. Therefore, a significant improvement in the fatigue resistance of the weld joint can be expected. In addition, when the depth f is increased, sufficient time is required, so the depth f is determined in consideration of the efficiency. Therefore, it is preferable that the depth f of the ultrasonic impact trace 11 is 1.0 mm or less. In addition, the depth f of the ultrasonic impact marks 11 is not particularly limited. As a quantity which cannot determine the position of the edge line of the weld toe part before a hitting process, the depth f of the ultrasonic impact trace 11 may be 0.05 mm or more, for example.

In addition, the apparatus disclosed in the above-mentioned patent documents 1-3 can be used for the ultrasonic impact apparatus 12 for performing an ultrasonic impact treatment. The shape of the vibration terminal (pin) of the ultrasonic impact apparatus 12 can be selected in consideration of conditions, such as the shape of the ultrasonic impact trace 11 to form.

For example, it is preferable to make the curvature radius of the axial cross section of the front end of the ultrasonic impact apparatus 12 into 1.0 mm or more and 10 mm or less. The shape of this tip becomes the shape of the ultrasonic impact trace 11 after the striking process. Therefore, when this radius of curvature is too small, a notch-shaped groove is formed in the weld end portion, whereby the stress concentration becomes high. On the other hand, if the radius of curvature is too large, it is difficult to form the ultrasonic impact marks 11 of a predetermined radius of curvature r even if the weld end is hit by the striking treatment depending on the shape of the weld bead. Therefore, in order to reliably form the ultrasonic impact trace of predetermined curvature radius r, it is preferable that the curvature radius of the axial cross section of the front-end | tip of the ultrasonic impact apparatus 12 is 1.0 mm or more and 10 mm or less. Moreover, it is more preferable that this radius of curvature is 1.5 mm or more and 5.0 mm or less.

What is necessary is just to select suitably the conditions of an ultrasonic shock treatment according to the fatigue characteristic required for a use. Therefore, the conditions of the ultrasonic shock treatment are not particularly limited. For example, it is preferable to vibrate a vibration terminal at the frequency of 20 Hz or more and 50 Hz or less, and to give an ultrasonic shock at the uniformity of 0.01 Hz or more and 4 Hz or less. However, since it is not necessary to strike by ultrasonic vibration, you may strike with low frequency or discontinuous period of 20 Hz or less. Thereby, the metal of the surface of a weld toe part plastic-flows, and releases the tensile residual stress formed with cooling of a fillet weld part, and can form a compressive residual stress field. Further, by repeatedly applying the ultrasonic impact treatment in a heat-insulated state in which heat generated by processing is not lost from the surface of the weld toe portion, the same action as that of hot forging can be given to the vicinity of the weld toe portion. As a result, the crystal structure near the weld edge is refined, and the fatigue property of the weld joint is improved.

(Example)

The steel plate (plate thickness 14mm x width 50mm x length 500mm) of the steel grade JIS SM490B described in JIS G3106 was used for the base plate. In addition, the steel plate (plate thickness 14mm x width 50mm x length 100mm) of the same steel grade was used for the gusset plate. This gusset plate was placed on the base plate as shown in FIG. 4A. That is, the longitudinal direction of the gusset plate and the longitudinal direction of the base plate 2 were matched to match the width direction of the gusset plate and the direction perpendicular to the upper surface of the base plate. Moreover, the gusset plate was arrange | positioned in the substantially center part (center part of upper surface) of the longitudinal direction and the width direction of a base plate.

The gusset plate arranged as mentioned above was fillet-welded to the base plate, and the test body of the out-of-plane gusset welded joint was produced. In addition, the same gusset plate as the gusset plate on the upper surface of the base plate was also provided on the lower surface of the base plate (not shown). The position of the gusset plate of this lower surface was the same position as the position of the gusset plate of the upper surface. 20 test bodies of the out-of-plane gusset welded joint were produced, and, among these 20 bodies, about 16 bodies, the notch part was formed in the gusset plate. In addition, among these 16 bodies, about 2 bodies are the same steel grade as a base plate, and the steel plate (plate thickness 20mm x width 50mm x length 100mm) thicker than other 14 gusset plates is used as a gusset plate. It was. In addition, the four test bodies which did not form a notch in a gusset plate are the out-of-plane gusset welding joint test bodies of a prior art example, as shown to FIG. 7B.

Of the 16 test specimens described above, the corner portions at the base plate side of both end portions in the longitudinal direction of the gusset plate were partially cut off to form the cutout portions 4. At this time, the cutting height a and the predetermined leg length d ₂ are determined to satisfy the equation 3, and the cutting angle θ (the angle formed between the surface of the base plate and the cutting surface of the gusset plate) is 25 to By changing to 80 °, the cut length (x) was changed.

In addition, the predetermined leg length d ₂ of the gusset plate side, and the predetermined leg length d ₁ of the base plate side were set based on welding design criteria etc., respectively.

All the test bodies were welded by carbon dioxide semi-automatic welding (GMAW: voltage 35 V, current 350 A, speed 3 mm / sec, gas composition CO ₂ 100%) using YGW-11 (JIS Z3321: wire diameter 1.4 mm) as the welding wire. It was.

In addition, the bridge length (d ₂ ') of the side gusset plate was less than 3/4 to more than 1/4 of the plate thickness (t ₂₎ of the gusset plate. In addition, the leg length d ₁ ′ on the base plate side was approximately the same length as the leg length d ₂ ′ on the gusset plate side, except for one specimen. These leg lengths d ₁ ′, d ₂ ′ were the predetermined leg length d ₁ on the base plate side and the predetermined leg length d ₂ on the gusset plate side, respectively, except for one specimen.

Thus, the UIT process was performed to the weld toe part on the base plate side of the torsion welding part of the test body of the out-of-plane gusset welded joint by the ultrasonic impact treatment apparatus, and the impact process trace was formed. The radius of curvature of the cross section in the axial direction of the tip of the vibration terminal (pin) of the ultrasonic impact treatment apparatus was 1.0 to 10.0 mm. In addition, the conditions of UIT process were the frequency of 27 Hz and the uniformity of 1 Hz. In the vicinity of the weld toe portion on the base plate side of the turning weld portion, a strike treatment mark having a curvature radius r of 1.0 to 10.0 mm and a surface depth f of 1.0 mm or less was formed. In addition, UIT process was not performed about two of the said 20 test bodies for comparison.

The fatigue test was done for the whole test body of the finally produced out-of-plane gusset welding joint. In this fatigue test, the number of repetitions until breakage under the conditions of a stress amplitude of 100 MPa and a stress ratio of 0.1 was measured.

Moreover, after the fatigue test, the substantially center of the thickness of the plate thickness of a gusset plate was cut along the longitudinal direction, and the sample for cross section observation was produced. The vicinity of the turning welds at both ends in the longitudinal direction of the specimen (test body) was corroded with nitrile to induce penetration length (the penetration length of the weld metal) x ', leg lengths d ₁ ′, d ₂ ′, and Lot thickness t was measured. Furthermore, the shape of the hitting treatment part of the weld toe part was observed.

The results are shown in Table 1.

In addition, the leg of the table _{1 (d 1 ', d 2} ') and the throat thickness (t) is the average value of the angular position (4 positions) is turning the weld formed. That is, for the leg lengths d ₁ ′, d ₂ ′ and the throat thickness t, the turning welds on both ends of the gusset plate in the longitudinal direction and the turning welds on both sides of the base plate are considered. Fatigue characteristics (number of repetitions to failure) are the values of each specimen.

In the specimens No. 2 to 5 and 7 to 20 subjected to UIT treatment, the impact treatment marks each having a curvature radius r of 1.0 to 10.0 mm and a depth f of 1.0 mm or less from the steel surface in the thickness direction of the base plate. It formed in this weld toe part, and the shape of the weld toe part was curved.

As shown in Table 1, in the case where no cutout was formed in the gusset plate, the test piece of No. 1, which was a conventional example which did not undergo UIT treatment, had a fatigue characteristic compared to the test piece of No. 2, which is a conventional example, which was subjected to UIT treatment. Was away. By this comparison, the improvement of the fatigue characteristic by UIT process was confirmed. In addition, in the test piece of No. 6, a sufficient cutout part was formed in a gusset plate, and each dimension (for example, leg lengths d ₁ ', d ₂ ') of the weld joint satisfied Equation 1, UIT processing has not been performed. Therefore, the number of repetitions until break was about 300,000 times. This number of repetitions is the same level as the test specimen of No. 1 which is not subjected to UIT. Thus, even when the cutout was formed and the leg lengths d ₁ ′ and d ₂ ′ were secured, the improvement effect of the fatigue characteristics by the enlargement of the throat thickness was not exhibited.

In the test bodies of Nos. 8 and 11, no cutout was formed in the gusset plate, and each dimension of the weld joint did not satisfy the equation (1). Also, the leg length d ₂ ′ on the gusset plate side was not sufficient. Therefore, even if the UIT process was performed, the fatigue characteristics of the weld joint could not be improved.

In the test piece of No.9, 10 and 12, but to form a cut-out in the gusset plates, it did not satisfy the expression (12) foot length (d ₂ ') of the side gusset plate. Therefore, the fatigue property of the weld joint could not be improved.

In the test samples No.11 and 12, because the short leg length (d ₂ ') than the thickness (t ₂₎ of the gusset plate, it was not possible to obtain the throat thickness of the plate thickness of the gusset plate (t _2). Therefore, the stress in the throat thickness part became high, the weld metal broke, and the lifetime of the test bodies of Nos. 11 and 12 was not very long.

No. 3 in which the cut-out portion having a sufficient dimension was formed in the gusset plate with respect to the above-described test body, and the fillet weld was made to satisfy the condition of the dimension of the fillet welded portion (for example, Equation 1), and the UIT treatment was performed. And in the test body of 4, as shown in Table 1, it turns out that the fatigue characteristic of a weld joint improves especially.

In the test body of No. 13, the notch angle (theta) is smaller than the test object of No. 3, and the initial notch angle (theta) is smaller than 45 degrees. Therefore, in order to ensure penetration into a welding route part, welding time was lengthened. As a result, the final penetration amount can be sufficiently secured, the penetration length x 'satisfies the expression (1), and the effect of improving the fatigue characteristics was seen. In addition, when the notch angle (theta) is small, high welding skill and time are required in order to ensure penetration to a welding route part. Therefore, it is industrially preferable to set the notch angle (theta) to an appropriate range.

The test body of No. 5 has cutouts and fillet welds of sufficient dimensions. Therefore, compared with the test body of No. 2 which did not form a cutout part in a gusset plate, the fatigue characteristic of the weld joint improved.

In the test body of No. 14, unlike the test body of No. 13, the notch angle (theta) exceeds 75 degrees. In this test piece, the cutout part was finally sufficiently infiltrated by welding. In this case, penetration angle (theta) 'was 75 degrees, and the dimension of a fillet weld part met the said Formula (1). As a result, the fatigue life extension effect of the weld joint was seen. Moreover, since the penetration angle (theta) 'of the test body of No. 14 was small compared with the test body of No. 5, the fatigue characteristic of the test body of No. 14 was higher than the test body of No. 5.

In the test body of No. 15, penetration angle (theta) 'was smaller than 45 degrees, and extension of fatigue life was seen. As with the test body of No. 13, the smaller the penetration angle θ ', the better. However, as described above, it is preferable that it is 30 ° or more in consideration of the penetration amount by realistic welding.

The test bodies of Nos. 16 and 17 are examples in which the leg length d ₁ ′ on the base plate side is relatively small. In the test body of No. 16, since the dimension of the fillet weld did not satisfy the equation (1), the stress concentration at the weld end was increased, and the effect of extending the fatigue life was not obtained. On the other hand, in the test body of No. 17, the dimension of a fillet weld part met Formula (1), and the effect which improves the fatigue characteristic of a weld joint was recognized.

In addition, the test body of No. 18 is an example in which penetration length x 'is comparatively small. In this test body, the fillet welded portion did not satisfy the equation (1), so that the stress concentration at the weld end was increased, and the effect of extending the fatigue life was not obtained.

The test body of No. 19 is an example in which the cutout height a is larger than the predetermined leg length d ₂ and the leg length d ₂ ′. In this test body, a cutout portion not covered with the weld metal remained in the turning welded portion on the gusset plate side, and cracks occurred from the welded edge 7 'on the gusset plate side, and sufficient fatigue characteristics were not obtained. In addition, since the penetration angle (theta) '(symbol * in Table 1) cannot be defined in the test body of No. 19, position A is used instead of the welding edge part 7', and the penetration angle (theta) 'is used. Evaluated.

In the test body of No. 20, the cutting angle (theta) is smaller than the test body of Nos. 3 and 13. In this test specimen, sufficient penetration to the tip of the cutout could not be ensured. However, the penetration length x 'satisfies Equation 1, and the effect of improving the fatigue characteristics was seen. Moreover, in the test bodies of No. 3 and No. 13, the burden of welding work was smaller than the test body of No. 20, and the penetration to the welding root part could be ensured easily. Therefore, it is industrially preferable to set the notch angle (theta) to an appropriate range.

From these results, it was confirmed that the fatigue property of a weld joint can be improved significantly by manufacturing the weld joint which satisfy | fills the said conditions.

According to the present invention, in the weld joint of the out-of-plane gusset, the penetration of the weld root portion can be efficiently deepened and the throat thickness can be increased, so that the concentration of stress in the weld root portion can be alleviated. Therefore, the effect of improving the fatigue property of the weld end portion by shot treatment such as shot peening or UIT treatment can be fully utilized, and the fatigue property of the entire out-of-plane gusset welded joint can be further improved.

1: out-of-plane gusseted welded joint (welded joint)
2: base plate (steel plate)
3: gusset plate (steel plate)
4: Notch of gusset plate (notch)
5: weld metal
6: melting line (fusion line)
7: welded edge part (welded edge part of base plate side)
7 ': welded edge part (welded edge part of gusset plate side)
8: welding root part
9: fillet weld
10: turning welding part
11: impact treatment mark (ultrasound impact mark)
12: ultrasonic shock treatment device (strike processing device)
13: position of the weld metal surface at the shortest distance from the weld root
A: position of the end in the height direction of the notch of the gusset plate
B: position of the longitudinal end of the notch of the gusset plate
C: Longitudinal end (corner) of gusset plate before forming cutout
C ': intersection point of the surface of the base plate and the repair which fell to the base plate from the welded edge part on the gusset plate side
C ": the intersection of the repaired surface (A) of the gusset plate to the base plate and the surface of the base plate
S: notch of gusset plate
a: height of cutout part (mm)
x: Length (mm) of cutout part [length from the base plate side edge part C of a gusset plate before forming a cutout part to the base plate side edge part B of a gusset plate after forming a notch]
x ': Penetration length (mm) (length from the intersection of the repair line which fell to the base plate from the weld end part on the gusset plate side, and the surface of a base plate to a welding root part)
θ: notch angle (°) [angle between the surface of the base plate and the notch (S)]
(theta) ': penetration angle (degree) (the line which connects the weld short part of a gusset plate side, and a welding root part, and the line which connects the intersection of the waterline which fell to the base plate from the weld short end part of a gusset plate side, and the surface of a base plate is formed. Angle)
d ₁ : Predetermined leg length (mm) on the base plate side
d ₂ : Predicted leg length on the gusset plate side (mm)
d ₁ ′: Leg length on the side of the base plate (mm)
d ₂ ′: Length of leg on gusset plate side (mm)
f: depth of impact treatment mark (mm)
r: radius of curvature of the striking mark (mm)
t: throat thickness

Claims (4)

It is a manufacturing method of the out-of-plane gusset welding joint provided with a base plate, a gusset plate, and a fillet welding part which protrude from the surface of this base plate,
One end in the plate width direction of the end portion in the longitudinal direction of the gusset plate is cut in the direction of the plate width w, and has a cutout height a, a cutout length x, and a cutout angle θ of 80 ° or less. Form a connection,
The gusset plate is disposed so that the end face in the direction of the plate width w of the gusset plate having the cutout faces the surface of the base plate, so that the predetermined leg length d ₂ on the gusset plate side is Fillet welding is performed so as to be equal to or more than the notch height a, and the leg length d ₂ ′ on the gusset plate side is 1/3 or more of the plate thickness t ₂ of the gusset plate, and the leg length d ₂ '), the fillet welded portion in which the leg length d ₁ ', the penetration length x 'and the penetration angle θ' on the base plate side satisfy x '+ d ₁ '> d ₂ '/ sin θ'. Forming,
A method of producing an out-of-plane gusseted welded joint, characterized in that a striking treatment is performed on at least a weld toe of the base plate side of the fillet welded portion. The said notch angle (theta) is 45 degrees or more and 75 degrees or less, The manufacturing method of the out-of-plane gusset welding joint of Claim 1 characterized by the above-mentioned. It is an out-plane gusset welding joint provided with a base plate, a gusset plate which protrudes from the surface of this base plate, and a fillet weld part,
In the fillet welding part, the leg length d ₂ ′ on the gusset plate side is 1/3 or more of the plate thickness t ₂ of the gusset plate, and the leg length d ₂ ′ and the base plate side The leg length d ₁ ′, penetration length x 'and penetration angle θ' satisfy x '+ d ₁ '> d ₂ '/ sin θ', and at least the base of the turning weld portion of the fillet welded portion. An out-of-plane gusseted welded joint, characterized in that a strike treatment mark is formed at the welded end of the plate side. The out-of-plane gusseted weld joint according to claim 3, wherein the penetration angle θ 'is 30 ° or more and 75 ° or less.

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