JP5627868B2 - Welding end tab and welding method - Google Patents

Description

  The present invention relates to a non-ferrous welding end tab capable of accurately processing a start point or an end point of a weld line when performing arc welding, and a welding method using the welding end tab.

  Since the welding arc is unstable at the start and end portions of the welded joint, poor penetration and blowholes are likely to occur on the start point side of the weld line where welding is started, and crater cracks are also likely to occur on the end point side. Steel end tabs are used to extend these weld defects to the outside of the joint by extending the weld line. However, with steel end tabs, it is necessary to tack weld the steel end tabs between the base metal and the base metal prior to the main welding, and the tack weld may become a short bead and the free end may be hardened. There was also.

  Furthermore, steel end tabs require a large amount of welding and a long welding time, and since there is no hot water at the end of the weld line, the finish of the work end face is poor, and it is an obstacle to finish the interior. However, it is fused with the base material by welding. If the steel end tab is left behind, there will be adverse effects such as stress concentration and places subject to fatigue load. If the steel end tab is used, the steel end tab is cut and then finished with a grinder. It was necessary to process.

  Therefore, a known technique called an alternative end tab or a solid tab (hereinafter referred to as “alternative tab”) has been implemented to improve the workability of steel end tabs (see Patent Document 1). Since these alternative tabs are made of, for example, ceramic and do not cause fusion with the base material, they can be easily removed from the base material after welding, and there are no places where stress concentration or fatigue load is received.

JP 9-182991 A

  When the conventional alternative tab is used, an unstable arc occurs at the start and end points on the main weld line in the welded joint, so that poor penetration and blowholes tend to remain at the start and end points. In order to eliminate such problems, for example, it has been proposed to perform welding by the back step method. In the backstep method, welding is started from a position several millimeters inside the end of the welding line starting point side, welding is performed toward the outer end, and then folded at the outer end, this time welding. Weld in the opposite direction along the line. Further, when the end point is reached, the welding is completed by returning about several mm from the end point. However, even if the back step method is used, a crater is always formed at a portion slightly returned from the end point, and an unhealthy portion remains in the joint. Therefore, even if the alternative tab is used when joining the base materials by arc welding, it is difficult to eliminate the joint failure because the welding failure remains in the joint. Therefore, advanced welding technology is required, and it was impossible to expect from all the technicians engaged in welding.

  The present invention aims to solve the above-mentioned problems, suppresses joint failures when joining base materials to each other by arc welding, and enables sound joining without depending on the skill of the welding technician. It is an object to provide a welding end tab and a welding method.

In the present invention, when a backing material is applied to an edge portion where the groove surface of the first base material is formed, the edge portion is joined to the second base material by arc welding. In a non-ferrous welding end tab that is used in contact with the first base material on at least one of the start point side and the end point side, it is continuous with the groove surface of the first base material and along the weld line An extension wall portion formed with an extended groove extension surface, and a hot water stop wall portion protruding from the extension wall portion so as to intersect the extension line of the weld line at the end of the groove extension surface. And at least a part of the groove extension surface is on the same plane as the groove surface, the hot water stop wall portion has a hot water stop surface in contact with the groove extension surface, and the groove of the groove extension surface. At least one of the surface other than the surface existing on the same surface as the surface and the hot water stop surface is a straight line along the normal line of the mounting surface in contact with the backing material And to tilt, groove extension surface is characterized by having a first inclined surface present on the groove surface and the same surface, a second inclined surface connected to the first inclined surface.

When performing arc welding, the welding end tab according to the present invention is disposed in contact with the first base material on at least one side of the start point side and the end point side of the welding line. When joining the first base material to the second base material, welding is performed along the weld line from the start point side toward the end point side. When the welding end tab is arranged on the start point side, the welding start point is shifted to a position outside the end portion of the first base material, that is, on the groove extension surface of the extension wall portion. Can do. As a result, even if a penetration failure or blowhole occurs at the starting point, the defect is removed from the end of the first base material, and the welded joint between the first base material and the second base material is Joined in a healthy state. Similarly, when the welding end tab is arranged on the end point side of the weld line, the welding end point is positioned outside the end portion of the first base material, that is, on the groove extension surface of the extension wall portion. Can shift up to. As a result, even if a penetration failure or blowhole occurs at the end point, the defect is removed from the end of the first base material, and the welded joint between the first base material and the second base material is Joined in a healthy state. Further, since the weld end tab is provided with the hot water stop wall portion, the shape of the toe end portion of the weld line can be adjusted without requiring a high degree of kneading. Furthermore, since the welding end tab is made of non-ferrous metal, it can be easily removed after joining the first base material and the second base material, stress concentration hardly occurs, and finishing processing such as cutting is unnecessary. Furthermore, since at least a part of the groove extension surface exists on the same plane as the groove surface, the portion of the bead that protrudes outward from the groove surface of the first base material is the groove of the first base material. The surface and the groove extension surface exist on the same surface, which is effective for sound joining. Further, the hot water stop wall portion has a hot water stop surface in contact with the groove extending surface, and at least one of the surface other than the surface existing on the same surface as the groove surface and the hot water stop surface of the groove extended surface is the back surface. Since it is inclined with respect to a straight line along the normal of the mounting surface that comes into contact with this material, it becomes easy to aim at the welding start point, effectively suppress the occurrence of welding defects, and workability is improved. improves. As described above, according to the present invention, it is possible to suppress a joint failure when joining base materials by arc welding and to enable sound joining without depending on the skill of the welding technician.

Further, it is preferable that the hot water stop surface is an inclined surface that is open so that the upper end is separated from the first base material as compared with the lower end on the backing material side. Since the hot water stop surface is an inclined surface and the upper end is open, it becomes easier to aim at the welding start point, the occurrence of welding defects is more effectively suppressed, and workability is further improved.

  Further, it is preferable that the groove extending surface is continuous with the groove surface. The portion of the bead that protrudes outward from the groove surface of the first base material is flush with the groove surface of the first base material and the groove extension surface, so there is no step and it is effective for sound joining. .

Furthermore, it is preferable that the groove extending surface has a first inclined surface that exists on the same plane as the groove surface, and a second inclined surface that is continuous with the first inclined surface. Since the second inclined surface is an inclined surface, it becomes easier to aim at the starting point of welding, the occurrence of welding defects is more effectively suppressed, and workability is further improved. Further, the first inclined surface may have a gradient that is continuous with the groove surface through chamfering.

  Furthermore, a front portion having a first extension wall portion and a first hot water stop wall portion, and a back portion having a second extension wall portion and a second hot water stop wall portion, the front portion and the back portion, Are preferably provided integrally in the same shape and arranged symmetrically with respect to the center of the virtual boundary surface when the front portion and the back portion are separated. According to this configuration, by using the front part and the back part properly, for example, the front part can be used on the start point side and the back part can be used on the end point side, thereby improving convenience.

  Further, according to the present invention, in the welding method using the above-described welding end tab, in the state where the backing material is applied to the edge portion on which the groove surface of the first base material is formed, the edge portion is attached to the second edge portion. After placing the welding end tab at the starting point and end point of the welding line, aiming at the groove extension surface of the welding end tab arranged at the starting point side of the welding line, and starting welding. Welding is performed toward the end point along the weld line, and welding is ended on the groove extension surface of the end tab for welding arranged on the end point side of the weld line. According to the present invention, even if a penetration failure or blowhole occurs at the start and end points of arc welding, the failure occurs on the groove extension surface of the welding end tab, and the first mother The welded joint between the first base material and the second base material is joined in a healthy state. As a result, joint failure when joining the base materials by arc welding is suppressed, and sound joining is possible without depending on the skill of the welding technician.

  According to the present invention, joint failure when joining base materials by arc welding is suppressed, and sound joining is possible without depending on the skill of the welding technician.

It is a perspective view of the end tab for welding concerning the embodiment of the present invention. It is a perspective view which shows the state which installed the end tab for welding which concerns on this embodiment. It is a perspective view which shows the state which cut | disconnected the end tab for welding which concerns on this embodiment at a virtual boundary surface, and divided | segmented into the front part and the back part. The front and back of the welding end tab which concern on this embodiment are shown, (a) is A1 arrow directional view of FIG. 1, (b) is A2 arrow directional view of FIG. The side surface of the end tab for welding which concerns on this embodiment is shown, (a) is B1 arrow directional view of FIG. 1, (b) is B2 arrow directional view of FIG. The plane and bottom face of the end tab for welding which concern on this embodiment are shown, (a) is C1 arrow directional view of FIG. 1, (b) is C2 arrow directional view of FIG. The state which installed the end tab for welding in the predetermined position is shown, (a) is a perspective view which expands and shows the 1st end tab for welding, (b) is a perspective view which expands and shows the 2nd end tab for welding. It is. It is a figure which shows the time of the start start of arc welding. It is a top view which shows the state which has arrange | positioned the 1st and 2nd end tab for welding to the both ends of a 1st preform | base_material, and is performing arc welding. The state which has arrange | positioned the conventional steel end tab to the both ends of a 1st preform | base_material, and shows arc welding, (a) is a top view, (b) is the cross section along the bb line of (a). FIG. The state which has arrange | positioned the conventional alternative tab to the both ends of a 1st preform | base_material, and shows arc welding is shown, (a) is a top view, (b) is sectional drawing along the bb line of (a). It is. It is a figure for demonstrating the position of the welding defect and welding defect which are easy to occur when performing arc welding, (a) is a figure which shows the welding defect in the first layer part at the time of an arc start, (b) is a surface layer It is a figure which shows the crater in a part. The end tab for welding which concerns on other embodiment of this invention is shown, (a) is a perspective view, (b) is a top view, (c) is a side view, (d) is a front view.

  Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a welding end tab according to the present embodiment, and FIG. 2 is a perspective view showing a state in which the welding end tab is placed in contact with the edge portion of the first base material. FIG. 3 is a perspective view showing a state in which the welding end tab is cut at a virtual boundary surface. 4 shows the front or back of the welding end tab, (a) is a view taken along arrow A1 in FIG. 1, and (b) is a view taken along arrow A2 in FIG. 5 shows a side surface of the welding end tab, (a) is a view taken along arrow B1 in FIG. 1, and (b) is a view taken along arrow B2 in FIG. Moreover, FIG. 6 shows the plane and bottom face of the welding end tab, (a) is a C1 arrow view of FIG. 1, (b) is a C2 arrow view of FIG.

  As shown in FIG. 2, for example, when the first base material 3 such as a beam member made of steel is joined to the second base material 5 made of columnar H-shaped steel or the like, an arc such as butt welding is used. Welding is performed. The first base material 3 has an edge portion 7 on which a groove surface 7 a is formed, and the first base material 3 is arranged so that the edge portion 7 abuts against the second base material 5. The A plate-like backing material 9 made of steel is applied to the edge 7 of the first base material 3 from the back side, and arc welding is performed along the longitudinal direction of the groove surface 7a. The first and second base materials 3 and 5 and the backing material 9 are fused and joined by arc welding to form a welded joint 11. A region along the longitudinal direction of the groove surface 7a is a weld line L where a weld bead is formed.

  At the start point La and end point Lb of the weld line L, welding defects and blowholes are likely to remain. The welding end tabs 1A and 1B are used in order to allow the welding defect and blowhole to escape to the outside rather than inside the welded joint 11. In this embodiment, two welding end tabs 1A and 1B are prepared, one (first) welding end tab 1A is arranged on the start point La side of the welding line L, and the other (second) welding end tab 1B is arranged. Arrangement is made on the end point Lb side of the weld line L, and arc welding is started aiming at the welding end tab 1A on the start point La side. Since the welding end tab 1A and the welding end tab 1B have the same shape and configuration, the following description will focus on the welding end tab 1A, and a detailed description of the welding end tab 1B will be omitted.

  The welding end tab 1A is made of a non-ferrous refractory material such as bronze, ceramics, or flux, but other materials can be used as long as they are heat resistant materials that do not melt during arc welding. . In addition, the ceramic system generally means a material having a sintering temperature of 1000 ° C. or higher, and the flux system means a material sintered at a temperature lower than about 1000 ° C.

  The welding end tab 1A has a shape in which a pair of diagonal portions of a virtual rectangular parallelepiped Re (see FIG. 1) are cut out in the same shape, and two inclined surfaces are formed in each diagonal portion. . For convenience of explanation, a half piece including one diagonal portion is referred to as a front portion 17, and a half piece including the other diagonal portion is referred to as a back portion 30. The front portion 17 and the back portion 30 (see FIG. 3) have the same shape when cut at a virtual boundary surface (virtual boundary surface) S. Further, the virtual boundary surface S is rectangular, and the front portion 17 and the back portion 30 are arranged so as to be point-symmetric with respect to the center of the boundary surface S. That is, as shown in FIGS. 3 to 5, the front surface and the back surface are point-symmetric with respect to the center C of the boundary surface S, the left surface and the right surface are point-symmetric, and the plane and the bottom surface are point-symmetric. Thus, since the front part 17 and the back part 30 are the same shape and can exhibit the same function, it can be used twice or more by one end tab 1A for welding, and the convenience improves.

  The welding end tab 1A is formed with first and second mounting surfaces 13A and 13B mounted on the backing material 9, and is abutted against the first base material 3 during arc welding. First and second contact surfaces 15A and 15B are formed. The first and second placement surfaces 13A and 13B are point-symmetric with respect to the center C of the boundary surface S, and the first and second contact surfaces 15A and 15B are with respect to the center C of the boundary surface S. It is point symmetric.

  The two inclined surfaces formed on the front portion 17 are connected so as to cross each other, and one inclined surface becomes the groove extending surface 19 and the other inclined surface becomes the hot water stop surface 23. The groove extending surface 19 is connected to the first contact surface 15A, and when the first contact surface 15A is abutted against the edge 7 of the first base material 3, the first base material 3 is provided. In other words, it has a gradient that exists on the same plane as the groove surface 7a, in particular, a gradient that is continuous with the same plane. A portion where the groove extending surface 19 is formed becomes an extension wall portion 21. Since the groove surface 7a and the groove extension surface 19 of the first base material 3 exist on the same surface, it is effective for sound joining. In particular, the groove surface 7a and the groove extension surface 19 are surfaces. Since they are connected to each other, the bead portion that protrudes outward from the groove surface 7a of the first base material 3 has no step and is effective for sound joining.

  The width of the groove extending surface 19 in the direction along the weld line L (hereinafter referred to as “extended width”) is, for example, about twice the thickness of the first base material 3 or 10 mm or more, preferably 2 Double or 15 mm or more, particularly preferably 2 times or 20 mm or more, particularly preferably 2 times or 25 mm or more. The advantage of setting the extension width to such dimensions will be described. When welding by the backstep method is performed, it is necessary to perform crater processing by turning back at the end point Lb. When the crater process is performed, the molten pool is not necessarily limited to a circle and an ellipse, and a molten pool is always formed. In the surface layer portion of the welding end tab 1A, an unstable arc state or crater contraction occurs. When welding is finished and the arc is stopped, the welded part immediately cools down from the outer periphery and heat shrinkage occurs. This heat shrinkage becomes maximum when the center finally cools and hardens, resulting in a large depression. This phenomenon is crater contraction. Since the crater Cr (see FIG. 12B) is easily cracked, the crater contraction must be accurately processed (crater processing) outside the first base material 3. In the present embodiment, a sufficient space for allowing the crater contraction to be performed outside the first base material 3 can be secured by adopting the above-described extension width.

  The hot water stop surface 23 is connected to the end of the groove extension surface 19, that is, the end opposite to the first contact surface 15 </ b> A so as to contact the groove extension surface 19 through a linear line segment. Yes. The portion where the hot water stop surface 23 is formed is the hot water stop wall portion 25, and the hot water stop wall portion 25 is provided so as to protrude from the extension wall portion 21 so as to intersect the extension line EL of the welding line L. The width of the first wall 13A (lower end side) placed on the backing material 9 is wider than the width of the second placement surface 13B side (upper side). It has become. As a result, the hot water stop surface 23 is an inclined surface that is open so that the upper end side is farther from the first base material 3 than the lower end side.

  Since the hot water stop surface 23 is an inclined surface that is open on the upper end side, the aiming operation of the first-layer welding torch 41 (see FIG. 8) is easier than when standing upright from the backing material 9. In this way, irregular end faces can be prevented, and the escape route for shielding gas can be expanded. Furthermore, irregularities in the end face after completion of welding also overlap with the upper layer welding so as to cover the lower layer welding, and as a result, it becomes easier to produce a good end surface finish. In addition, although it can enjoy various advantages by making it the inclined surface which the hot water stop surface 23 is open on the upper end side, the present invention is not limited to the case where the hot water stop surface 23 is an inclined surface, The aspect which stands | starts up perpendicularly | vertically from the material 9 is also included.

  The back portion 30 has the same shape as the front portion 17, and includes an extension wall portion 33 in which a groove extension surface 31 is formed and a hot water stop wall portion 37 in which a hot water stop surface 35 is formed. The portion 37 is provided so as to protrude from the extension wall portion 33 so as to intersect the extension line EL of the welding line L when installed at a predetermined position. The extension wall portion 21 of the front portion 17 corresponds to a first extension wall portion, and the hot water stop wall portion 25 corresponds to a first hot water stop wall portion. The extension wall portion 33 of the back portion 30 corresponds to a second extension wall portion, and the hot water stop wall portion 37 corresponds to a second hot water stop wall portion.

  As shown in FIGS. 7 and 9, the first welding end tab 1A and the second welding end tab 1B are arranged so as to sandwich the groove surface 7a of the first base material 3 from the left and right. The first welding end tab 1 </ b> A and the second welding end tab 1 </ b> B are installed at predetermined positions using presser fittings (not shown) using leaf springs or the like. A first welding end tab (see FIG. 6A) 1A is arranged on the start point La side of the welding line L using the front portion 17, and a second welding end tab (see FIG. 6B) 1B. Is arranged on the end Lb side of the weld line L using the back portion 30.

  The first welding end tab 1A on the start point La side is placed on the backing material 9 so that the front portion 17 is aligned with the groove surface 7a, and the first contact surface 15A abuts against the first base material 3. It is done. In this state, the groove extension surface 19 of the front portion 17 is flush with the groove surface 7a. When the welding end tab 1 </ b> A is installed at a predetermined position, a bag path-like region is formed by the groove extending surface 19, the hot water stop surface 23, the backing material 9 and the wall surface of the second base material 5.

  The second welding end tab 1B on the end point Lb side is arranged with the welding end tab 1A on the start point La side turned upside down, and is placed on the backing material 9 so that the back portion 30 is aligned with the groove surface 7a. The second contact surface 15B is abutted against the first base material 3. In this state, the groove extending surface 31 of the back portion 30 is flush with the groove surface 7a. When the welding end tab 1 </ b> B is installed at a predetermined position, a bag path-like region is formed by the groove extending surface 31, the hot water stop surface 35, the backing material 9 and the wall surface of the second base material 5.

  When starting arc welding, arc welding is started aiming at the position of the corner where the groove extending surface 19 of the first welding end tab 1A on the start point La side and the hot water stop surface 25 intersect (see FIG. 8). ). Thereafter, the welding torch 41 is moved toward the end point Lb along the longitudinal direction (weld line L) of the groove extending surface 19 and the groove surface 7a. At the end point Lb, the welding torch 41 is disengaged from the first base material 3 and reaches the inside of the bag path area of the second welding end tab 1B. By using the welding end tabs 1A and 1B, welding defects and blowholes that are likely to occur on the start point La side and the end point Lb side of the weld line L can be released to the outside of the weld joint 11, and the welding end tabs 1A and 1B Since 1B can be easily removed from the welded joint 11, it does not fuse with the base material 3 at the end of the weld line L, so that the occurrence of stress concentration is suppressed, and the subsequent finishing process is also unnecessary.

  Next, the advantages of using the welding end tabs 1A and 1B will be specifically described in comparison with a conventional end tab. First, a conventional steel end tab (hereinafter referred to as “steel end tab”) 100 will be described. FIG. 10 is an explanatory diagram when arc welding is performed using the steel end tab 100, and (a) is a plan view showing a state in which the steel end tabs 100 are arranged on both sides of the first base material 3. (B) is sectional drawing along the bb line of (a). In FIG. 10A, the path of the welding torch is indicated by an arrow, and the arc welding is performed using the back step method.

The steel end tab 100 is based on the basic concept of the end processing of butt welding, and when the steel end tab 100 is attached, the base material 3 and the backing material 9 must be temporarily fixed by tack welding. . The steel end tab 100 is a block having an inclined surface 100a which is flush with the groove surface 7a, and the temporary fixing is performed by tack welding in principle other than the groove surface 7a. portion P ₁ only tack welds between the leading face 7a and the inclined surface 100a is allowed. Here, the site P ₁ between the groove surface 7a of the base member 3 and the inclined surface 100a will be a component of the welding during welding completion, be avoided rapid heating and quenching in a short bead even a tacking It must be a part. Further, the steel end tab 100 is fused at the time of completion of welding, and it is necessary to avoid damage due to stress concentration in order to generate stress concentration at the steel end tab 100. It is necessary to apply. Further, since the steel end tab 100 does not have a portion that becomes a hot water stop wall, it is necessary to prepare only the weld metal by using the welding rod technique, but such a process is very difficult. It is difficult and requires a high degree of skill.

  Compared to the steel end tab 100, the welding end tabs 1A and 1B according to the present embodiment can be installed at a predetermined position by restraint with a presser fitting and do not require temporary fixing, so that the rapid heating and quenching phenomenon which is an adverse effect does not occur. Furthermore, since the welding end tabs 1A and 1B are non-ferrous refractories such as ceramics, they can be easily peeled off by removing the presser fitting after the main welding is completed. Only the bead part. For this reason, stress concentration does not occur as in the case where the steel end tab 100 is used, and there is no structural problem even in a portion subjected to repeated loads. Furthermore, the finishing process is unnecessary, and the work efficiency associated with the welding work is greatly improved. Furthermore, since the welding end tabs 1A and 1B have the hot water stop wall portions 25 and 37 in which the hot water stop surfaces 23 and 35 are formed, the shape of the toe end portion of the weld line L is adjusted without requiring a high degree of kneading. Can do.

  Next, a conventional alternative tab will be described. FIG. 11 is an explanatory diagram when arc welding is performed using the alternative tab 200, and (a) is a plan view showing a state in which the alternative tab 200 is arranged on both sides of the first base material 3. b) is a sectional view taken along line bb in FIG. In addition, in Fig.11 (a), the track | orbit of a welding torch is shown by the arrow, and the state which performs arc welding using the back step method is shown.

  It can be evaluated that the alternative tab 200 is made of ceramic or the like, and does not require temporary fixing by tack welding, and does not cause the problem of rapid heating and quenching unlike the steel end tab 100. However, since the welding start point at the time of arc start is in the welded joint 203, there is a very high possibility of causing a defect in the welded joint 203 due to an unstable state at the time of arc start (FIG. 12A). reference). In addition, when trying to process the end point of the weld line by the back step method, the crater Cr remains on the surface layer portion of the main weld line (see FIG. 12B), ensuring a good and healthy weld joint 203. It is very difficult to do. FIG. 12 is a diagram for explaining a place where a welding defect occurs due to arc welding. (A) shows a welding defect that occurs in the first layer at the start of welding, and (b) occurs in the surface layer portion. A crater is shown.

  On the other hand, according to the welding end tabs 1A, 1B according to the present embodiment, the welding end tabs 1A are arranged on the start point La side, for example, because the extension wall portions 21, 33 are formed with the groove extending surfaces 19, 31. In this case, the welding start point (welding line start point) La of the first layer Ff can be shifted to the bag path region of the welding end tab 1A, and there is a penetration failure or the like that is likely to occur due to an unstable voltage current at the arc start. Can be driven out. Further, in the welding end tab 1A, the width of the groove extending surfaces 19 and 31 in the weld line L direction is, for example, twice the thickness of the first base material 3 or 25 mm or more. Therefore, for example, when the welding end tab 1B is arranged on the end point Lb side, the crater Cr formed on the surface layer portion at the time of completion of welding is placed outside the welded joint 11 so as to fit in the bag path area of the welding end tab 1B. It can be formed in a straightforward manner, and even a welding beginner can ensure a safe and secure welding.

  As shown in FIG. 12A, defects such as poor penetration and blowholes at the start of the first layer Ff are on the side to be welded rather than the groove surface 7a side of the first base material 3. It is likely to occur at the contact point between the base material, that is, the second base material 5 and the backing material 9. This phenomenon is also caused by the fact that the second base material 5 is perpendicular to the backing material 9 and the root gap width of the first layer Ff is as narrow as about 7 mm, making it difficult for the welding technician to see. . However, in the welding end tab 1A, since the hot water stop surface 23 is an inclined surface that spreads on the upper end side, it is easy for a welding engineer to aim at the welding start location. It becomes difficult to occur.

  Furthermore, the welding line L can be extended to the outside of the weld joint 11 of the first base material 3 by welding using the welding end tabs 1A and 1B according to the present embodiment, so that nondestructive inspection (mainly ultrasonic flaw detection inspection) is performed. Will also be easier. In the ultrasonic flaw detection, if the inspection site is extremely close to the probe due to the nature of the inspection equipment, it becomes a dead zone and an accurate inspection cannot be performed. In the case of the above-mentioned alternative tab 200, since the stop wall is formed at a distance of about 2 to 3 mm from the first base material 3, accurate inspection is impossible. However, since the welding end tabs 1 </ b> A and 1 </ b> B have the groove extending surfaces 19 and 31, the weld line L is outside the weld joint 11 of the first base material 3, specifically, the first base material 3. It can be extended to a position about 25 mm away from the toe portion, and the end of the base material of the welded joint 11 can be accurately evaluated.

  Further, regarding the superiority of the welding end tabs 1A and 1B according to the present embodiment, for example, the groove extension surface and the hot water stop surface are curved without the groove extension surface extending in a planar shape along the weld line. This will be described in comparison with a continuous form (hereinafter referred to as “comparative form”). In the case of the comparative embodiment, as in the present embodiment, relaxation of stress concentration is recognized and the torch operation may be facilitated. However, in the comparative form, since the groove extension surface does not extend along the weld line, the region for allowing the end of the weld line to escape to the outside of the base material cannot be sufficiently widened. The defect at the time of arc start of the first layer and the crater processing of the surface layer portion cannot be performed. On the other hand, in the welding end tabs 1A and 1B, the groove extending surface 19 extends in a planar shape along the weld line L, and further on the hot water stop surface 23 so as to be bent through a straight line segment. They are in contact with each other. As a result, it is easy to widen the area for allowing the end of the weld line L to escape to the outside of the base material 3, and suppresses joint defects when joining the base materials 3 and 5 by arc welding, Sound joining can be achieved without depending on the skill of the welding technician.

(Welding method)
Next, the welding method according to the present embodiment will be described with reference to FIG. The first base material 3 has an edge portion 7 on which a groove surface 7a having a predetermined gradient is formed. A backing material 9 is applied to the edge portion 7 from the back side and temporarily fixed by welding. The above-mentioned welding end tabs 1A and 1B are in contact with both ends of the edge portion 7 in the longitudinal direction, and are fixed by presser fittings. The edge portion 7 of the first base material 3 is disposed so that the backing material 9 abuts against the second base material 5 and is temporarily fixed as appropriate to complete the preparation for the main welding.

  In the present embodiment, the first base material 3 and the second base material 5 are joined by multi-layer welding by arc welding. Further, in the present embodiment, arc welding using the back step method is illustrated, but a welding method that directly targets a portion where the hot water stop surface 23 or the hot water stop surface 35 contacts the backing material 9 may be used.

  First, aiming at the bag path region where the groove extending surface 19 of the first welding end tab 1A disposed on the start point La side of the weld line L is aimed, arc welding is started to form the first layer Ff. This position is a position shifted outward from the end of the edge 7 of the first base material 3. Thereafter, the welding torch 41 is moved, and the toe end of the weld line L is neatly aligned with the hot water stop surface 23, and then turned back and moved toward the end point Lb, so that the groove extension surface 19 and the first base material 3 are moved. Welding is performed along the groove surface 7a. On the end point Lb side of the weld line L, welding is continued to intentionally escape from the end of the first base material 3 to the groove extension surface 31 of the second welding end tab 1B. After aligning the toe ends of L cleanly, they are folded back within the bag path region of the welding end tab 1B, and crater processing is performed on the surface layer portion on the groove extension surface 33 of the welding end tab 1B to complete welding.

  According to the welding method using the welding end tabs 1A and 1B and the welding end tabs 1A and 1B, even if a penetration failure or a blow hole occurs at the start point La and the end point Lb of the weld line L, the problem is The welded joint 11 between the first base material 3 and the second base material 5 is joined in a healthy state. As a result, joint failure when joining the base metals 3 and 5 by arc welding is suppressed, and sound joining is possible without depending on the skill of the welding technician.

  A welding end tab 1C according to another embodiment of the present invention will be described with reference to FIG. The welding end tab 1C is made of a non-ferrous refractory material made of bronze, ceramics, flux, or the like, similar to the above-described welding end tab 1A, and is mounted on the backing material 9. Mounting surfaces 51A and 51B are formed, and first and second contact surfaces 52A and 52B that are abutted against the first base material 3 during arc welding are formed. In addition, in the welding end tab 1C, the mounting surfaces 51A and 51B have a thin width of about 17 mm, but may be a thick type of 40 mm or more, for example.

  The welding end tab 1C has a front portion 50 and a back portion 60 that have the same shape when cut at the virtual boundary surface S. The front portion 50 and the back portion 60 are located at the center of the virtual boundary surface S. They are arranged so as to be point-symmetric with respect to each other. In addition, since the front part 50 and the back part 60 are the same form and can exhibit the same function, it can be used twice or more by one end tab 1C for welding, and the convenience improves. Hereinafter, the front portion 50 will be mainly described, and the description of the back portion 60 will be omitted.

  The front portion 50 exists on the same plane as the groove surface 7a of the first base material 3 and is connected to the first inclined surface 51a and the first inclined surface 51a extending along the weld line L. An extension wall portion 51 formed with two inclined surfaces 51b and a hot water stop wall portion protruding from the extension wall portion 51 so as to intersect the extension line of the weld line L at the end of the second inclined surface 51b 52.

  In the aspect using the front portion 50, the first inclined surface 51a is flush with the groove surface 7a of the first base material 3 when the welding end tab 1C is abutted against the first base material 3. And has a gradient that continues through chamfers. The inclination angle α of the first inclined surface 51a according to this embodiment is, for example, about 35 degrees (gradient) with respect to a straight line along the normal line of the mounting surfaces 51A and 51B that are in contact with the backing material 9. Is about 55 degrees). The second inclined surface 51b has a smaller inclination angle (gradient) than the inclination angle α of the first inclined surface 51a. A groove extending surface 53 is configured by the first inclined surface 51a and the second inclined surface 51b. The width in the direction along the weld line L (extended width) of the groove extending surface 53 is, for example, about twice the thickness of the first base material 3 or 10 mm or more, preferably 2 times or 15 mm or more, Particularly preferably, it is 2 times or more than 20 mm, particularly preferably 2 times or more than 25 mm.

  The hot water stop wall portion 52 is formed with a hot water stop surface 52 a continuous with the groove extending surface 53. The hot water stop surface 52a is orthogonal to the extension line EL of the weld line L (see FIG. 9). Further, the angle β between the intersecting line of the hot water stop surface 52a and the second inclined surface 51b and the straight line along the normal line of the placement surfaces 51A and 51B is, for example, about 15 degrees.

  The welding end tab 1C is formed by integrally forming the front portion 50 and the back portion 60 described above. Further, the edge portion of the welding end tab 1C is chamfered such that an isosceles triangle having a cross section of about 3 mm is cut off. This chamfer is formed so that it can be easily removed from the mold at the time of manufacture, i.e., to prevent chipping. However, the chamfering of the portion in contact with the welded portion can further avoid stress concentration in the welded portion. There is also an effect that it can be easily removed after welding.

  According to the welding method using the welding end tab 1C and the welding end tab 1C described above, the base material 3 is formed by arc welding in the same manner as the welding method using the welding end tabs 1A and 1B and the welding end tabs 1A and 1B. , 5 can be prevented from being defective when joined together, and can be joined smoothly without depending on the skill of the welding technician.

  Furthermore, according to the welding end tab 1C, the first inclined surface 51a of the groove extending surface 53 is present on the same plane as the groove surface 7a, which is effective for sound joining.

  The present invention is not limited only to the above embodiment. For example, the arrangement of the base materials is not limited to the butt joint, and may be a groove joint.

  1A, 1B, 1C ... end tab for welding, 3 ... first base material, 5 ... second base material, 7 ... edge, 7a ... groove surface, 9 ... backing material, 17, 50 ... front part, 19, 31, 53 ... groove extension surface, 21, 33, 51 ... extension wall portion, 25, 37, 52 ... hot water stop wall portion, 23, 35, 52a ... hot water stop surface, 30, 60 ... back portion, L ... weld line, La ... start point, Lb ... end point, EL ... extension line of weld line, S ... virtual boundary surface, C ... center of virtual boundary surface.

Claims (4)

When the edge is joined to the second base material by arc welding with the backing material applied to the edge where the groove surface of the first base material is formed, the start and end points of the weld line In a non-ferrous welding end tab that is used in contact with the first base material on at least one side of the side,
An extension wall portion formed with a groove extension surface extending along the weld line and continuing to the groove surface of the first base material;
A hot water stop wall portion protruding from the extension wall portion so as to intersect the extension line of the weld line at the end of the groove extension surface;
At least a part of the groove extension surface is present on the same plane as the groove surface;
The hot water stop wall portion has a hot water stop surface in contact with the groove extension surface,
Of the groove extension surfaces, at least one of the surface other than the surface existing on the same surface as the groove surface and the hot water stop surface are along the normal line of the mounting surface that is in contact with the backing material. Inclined with respect to a straight line ,
The groove extension surface includes a first inclined surface existing on the same plane as the groove surface, and a second inclined surface connected to the first inclined surface. . Said first inclined surface, welding end-tab according to claim 1, characterized in that it has a gradient as continuous through the chamfer on the open crest. A front portion having the first extension wall portion and the first hot water stop wall portion; and a back portion having the second extension wall portion and the second hot water stop wall portion;
The front portion and the back portion are integrally provided in the same shape, and are arranged point-symmetrically with respect to the center of the virtual boundary surface when the front portion and the back portion are separated. The end tab for welding according to claim 1 or 2, characterized in that: In the welding method using the end tab for welding as described in any one of Claims 1-3 ,
In a state where the backing material is applied to the edge portion where the groove surface of the first base material is formed, the edge portion is arranged toward the second base material, and the welding end tab is connected to the start point of the welding line and Placed at the end point, after starting welding with aiming at the groove extension surface of the welding end tab arranged on the start point side of the weld line, then welding toward the end point along the weld line, A welding method comprising: terminating welding on the groove extension surface of the welding end tab disposed on the end point side of the welding line.

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