JP2007167928A - Patch for electroslag welding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steel patch used for electroslag welding of a T-joint, a patch that hardly causes weld defects such as a weld residue in a groove corner even with smaller welding heat input and that is suitable for welding in assembling a box column for construction. <P>SOLUTION: The patch has a cross section which is a rectangle having in part a notched recess due to rolling. The cross section of the recess is composed of a curve having a radius of curvature ≥1 mm at any position in the proximity to an end, at least on the side of a diaphragm and further on the side of a skin plate. Otherwise, it is composed of a curve having a radius of curvature ≥1 mm at any position in the proximity to the end on the diaphragm side, and a straight line connecting with this curve and intersecting at the skin plate at an angle of ≥90°. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a steel metal used for electroslag welding of a T-shaped joint, and in particular, even if the welding heat input is reduced, weld defects such as unmelted portions are hardly generated at the corners of the groove, and it is used for construction. The present invention relates to an apparatus suitable for assembly welding of a box column.

  An electroslag welding method is widely used as a vertical automatic welding method. In particular, consumable nozzle type electroslag welding or non-consumable nozzle type electroslag welding as a simple electroslag welding method for welding of diaphragm blind portions of steel box columns used in buildings such as buildings (for example, Patent Document 1) Is generally adopted.

  In welding the diaphragm blind portion of the steel box column using these welding methods, a strip-shaped rolled steel material called a flat bar having a rectangular cross section is used as a gold cut after being cut to an appropriate length.

  FIG. 4 schematically shows the arrangement of the diaphragm 100, the gold 300, and the skin plate 200 in electroslag welding. The diaphragm 100 is sandwiched between the gold 300 and the skin plate 200 and a groove 400 having a rectangular cross section. A T-shaped joint having

FIG. 9 shows a T-shaped joint after welding. The slag is heated by energizing the molten slag through a groove 400 having a rectangular cross section surrounded by the diaphragm 100, the two metal pieces 300, and the skin plate 200. The welding wire is supplied and melted to fill the groove with the weld metal 500, and the diaphragm 100 and the skin plate 200 are welded with the leg length L (the penetration width on the skin plate side).
JP-A-57-156684

  By the way, in recent years, high-strength materials such as YP385 or higher have been used for box columns as the buildings become super high-rise, but generally the toughness of welded joints tends to decrease with higher strength materials. Therefore, the development of steel materials for large heat input welding and the upper limit of welding heat input have become necessary.

  However, in the case of electroslag welding, welding is generally performed with an extremely large heat input of 500 to 1000 kJ / cm, and when the welding heat input is reduced, the welded portion is less melted. It tends to occur.

  Further, it is necessary to secure a certain length of the weld metal leg length in order to secure the bonding strength between the skin plate and the diaphragm. However, if the welding heat input is low, the penetration is reduced, and it is difficult to secure the leg length.

  In other words, in electroslag welding, a gold having a rectangular cross section is used, so the heat is generated by the slag so that the gold is melted deeply, the corners of the groove are rounded, and the weld metal is spread to the corners, so that an unmelted part does not occur. In addition, the leg length is secured, but since the metal has a high thermal conductivity, a large amount of heat is required to melt the metal.

  FIG. 10 shows the T-shaped joint after completion of welding when welding is performed with a small heat input. Since the welding heat input is small and the penetration of the metal 300 is small, the leg length L is short and sufficient joint strength cannot be ensured. Moreover, the unmelted part 6 may generate | occur | produce in a corner.

  Therefore, an object of the present invention is to provide an electroslag welding gold which can be obtained at a low cost without generating an unmelted portion even when welding heat input is reduced, ensuring a leg length.

  The object of the present invention can be achieved by the following means.

1. A steel metal used for electroslag welding of a skin plate and a diaphragm, and a recess is provided so as to obtain a weld metal part having a desired cross-sectional shape in the welding. Money.
2. 2. The electroslag welding according to 1, wherein a cross-sectional shape of the recess is a curve having a radius of curvature of 1 mm or more at any point from a position in contact with the diaphragm to a position in contact with the skin plate. This money.
3. 3. The electroslag welding tool according to 1 or 2, wherein the curve constituting the concave portion is in contact with the tip and the skin plate at an angle of 90 ° or more.
4). The aforesaid recess for electroslag welding according to any one of claims 1 to 3, wherein the recess is formed by rolling.

  In the present invention, the portion where the conventional planar shape is melted with the rectangular metal is recessed from the beginning, and the portion is filled with the weld metal obtained by melting the wire. The shape is easy to spread, and the concave portion is formed by rolling in the gold manufacturing process. Therefore, according to this invention, the following effects are acquired and it is very useful industrially.

1 Leg length can be ensured even under small heat input conditions without the occurrence of insufficient melting.
2 Since the recess is formed by rolling, the gold can be obtained at a much lower cost than when the recess is formed by machining or the like.
3 Electroslag welding is possible even under welding conditions with low heat input, so that a reduction in the toughness of the heat affected zone can be prevented, and the safety of the structure is improved.

Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a plan view for explaining the configuration of a groove portion for electroslag welding using the gold according to one embodiment of the present invention, and FIG. 2 shows a welded portion.

  In these figures, 1 is a diaphragm, 2 is a skin plate, 3 is a gold, 4 is a groove, 5 is a weld metal (including a heat-affected zone at the outer edge), and 31 is a recess provided in the metal 3. , L indicates the leg length.

  In electroslag welding, the groove 4 is filled with a weld metal obtained by melting a wire (not shown), and the skin plate 2 and the diaphragm 1 are welded.

  The gold 3 according to one embodiment of the present invention is a rectangle having a notch in the recess 31 on the groove 4 side. In the cross-sectional shape of the metal 3, the recess 31 is a circle that starts from the position where one side of the rectangle is in contact with the surface on the groove side 4 of the diaphragm 1 and swells outside the groove 4 toward the side where the skin plate 2 contacts. An arcuate curve is formed by rolling.

  The formation of the recesses is performed in the production process of a rectangular gold (flat bar), which uses one or more rolling rolls having convex portions corresponding to the concave portions, and transfers the shape of the convex portions to the gold. By doing so, a recess is formed.

  The concave portion 31 is configured by a curve having a radius of curvature of 1 mm or more at any position from the position where the skin plate 2 is in contact to the position where it is in contact with the diaphragm 1.

  That is, the concave portion 31 is a portion corresponding to a penetration shape when the metal 3 is rectangular in a sound welded portion obtained by electroslag welding a T-shaped joint constituted by the diaphragm 1 and the skin plate 2. .

  As a result, as shown in FIG. 2, since the concave portion 31 corresponding to the weld metal penetration shape is formed in the metal 3 in advance, the leg length L can be obtained by slightly melting the metal 3 with a small welding heat input. Can be lengthened.

  FIG. 3 shows an enlarged view of the groove portion using the metal 3 according to one embodiment of the present invention, and the shape of the recess 31 is a smooth curve so that the slag and the weld metal in the molten state are sufficiently distributed. It is desirable that the radius of curvature r is 1 mm or more at any position.

  If the radius of curvature r is as small as less than 1 mm, the molten slag and the molten metal cannot penetrate along the concave portion 31 due to the surface tension, and an unmelted portion is likely to occur.

  Further, at the point P where the metal 3 and the skin plate 2 are in contact with each other, the molten metal does not easily reach the corners, so that an unmelted portion is likely to occur. If the angle α formed by the curve formed by the surface of the skin plate 2 on the groove 4 side and the recess 31 at the point P is 90 ° or more, the molten metal is sufficiently filled, and the occurrence of an unmelted portion is prevented. preferable.

  In the present invention, the recess 31 provided in the metal 3 has the same shape in the longitudinal direction of the metal 3, that is, the welding progress direction, and has a bilaterally symmetrical shape with the diaphragm interposed therebetween.

    Electroslag welding was performed using a T-shaped joint in which the diaphragm 1 and the metal plate 3 sandwiching the left and right of the diaphragm 1 and the skin plate 2 shown in FIG. 7 were combined. In the figure, W is the thickness of the diaphragm, D is the depth of the groove, and T is the thickness of the skin plate.

  As the metal 3, the one having a rectangular cross-sectional shape shown in FIG. 8 and the shape according to the present invention shown in FIGS. 5 and 6 were used.

  The cross-sectional shape shown in FIG. 5 has a concave shape as a whole due to rolling, a curve composed of a part of a quarter circle of R = 7 mm on the side close to the end in contact with the diaphragm, and a skin plate, It is a shape having a straight line portion that is orthogonal. The straight portion is 90 degrees or more, and it is preferable that welding defects are less likely to occur when intersecting with the skin plate.

  The cross-sectional shape shown in FIG. 6 is a concave shape as a whole by rolling, a curve consisting of a part of a quarter circle of R = 7 mm on the side near the end in contact with the diaphragm, and R = on the side near the end in contact with the skin plate. 3 has a curved line consisting of a part of a circle, and the vicinity of both ends has a shape connected by a straight line, and the gold plate and the skin plate intersect at about 132 °.

  Using these golds, a T-shaped joint was formed, and electroslag welding was performed under the conditions shown in Table 1. The welding length was 500 mm.

  Condition 1 in Table 1 is a comparative example using a conventional rectangular gold-plated metal. Conditions 2 and 3 in Table 1 are examples using the gold according to the present invention. The welding conditions are the same except that conditions 1, 2 and 3 are different. As welding conditions, conditions with less welding heat input than usual were selected.

  Table 2 shows the results. As a result of the welding, the leg length L of the welded part and the presence or absence of the unmelted part were judged from the shape of the weld metal cross section, and leg length (L)> diaphragm thickness (W) and no unmelted part were accepted.

    As shown in the table, when a conventional rectangular shaped gold was used, an unmelted portion was generated at the corner of the groove, and the leg length was shorter than the diaphragm thickness, resulting in an imperfect weld. On the other hand, when the gold according to the present invention was used, there was no unmelted portion and the leg length was sufficient, and a sound welded portion was obtained.

The top view which shows an example of the T-shaped coupling using the gold which concerns on one Example of this invention. The top view after welding of the T-shaped coupling shown in FIG. FIG. 2 is an enlarged view of the T-shaped joint shown in FIG. Conventional example. The money which concerns on one Example of this invention (plan view). The money (plan view) according to another embodiment of the present invention. The T-shaped coupling (top view) used for the Example. Conventional example. The top view after welding of the T-shaped coupling shown in FIG. The figure which shows the welding part (penetration shape, welding defect) in the T-shaped coupling shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Diaphragm 2 Skin plate 3 Gold 4 Groove 5 Weld metal (The outer edge includes a weld heat affected zone)
31 Concave portion L Leg length 100 Diaphragm 200 Skin plate 300 Gold 400 400 Groove

Claims (4)

  A steel metal used for electroslag welding of a skin plate and a diaphragm, and a recess is provided so as to obtain a weld metal part having a desired cross-sectional shape in the welding. Money.   2. The electroslag according to claim 1, wherein the cross-sectional shape of the concave portion is configured by a curve having a radius of curvature of 1 mm or more at any point from a position in contact with the diaphragm to a position in contact with the skin plate. Money for welding.   3. The electroslag welding tool according to claim 1, wherein the curve constituting the concave portion is in contact with the tip and the skin plate at an angle of 90 ° or more. 4. The electroslag welding tool according to any one of claims 1 to 3, wherein the recess is formed by rolling.

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