KR830001085Y1 - Two-line grooved welding support - Google Patents

Abstract

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Description

Two-line grooved welding support

1 and 2 are cross-sectional views showing a conventional welding backup.

3 is a cross-sectional view of the welding support of the present invention.

4 is a cross-sectional view of a weld formed by one-side welding using a single pass using the welding support of FIG.

The present invention relates to a welding support for use in welding, and more particularly to a non-metal welding support for use in single pass welding of thick plates at high temperatures using a large current.

In the case of manufacturing a large tank or ship using metal plates, the edges of the metal plates are welded together. Then, the weld joint is completely penetrated from the welding surface of the base material to the root, that is, from the upper surface to the molten welding material. It is preferable to make it form. In order to form a complete 100% weld seam (i.e. to fully penetrate from the molten weld surface to the root), the weld seam is conventionally multi-pass welding on each surface of the plates to be welded. Has been formed. This can form a complete weld seam, but it is expensive and time consuming because it requires welding on both sides.

In view of this, several welding methods have been proposed to weld only on one side. As such a welding method, the single-sided welding method using a rectangular, square, or bar-shaped welding support is mentioned, for example. Such a welding support is positioned at the center of one side of the welding plate to act to hold the molten weld material formed during welding. When the molten weld material is cooled, it is formed as a weld seam or bead, so that the welding is not necessary again on the opposite side of the plate on which the weld is performed.

Bar-shaped metal supports made of copper or similar material to the plate to be welded shall be provided with an inorganic partition so that they are not joined to the welded joint during welding. Therefore, it is desirable to use non-metallic welding supports, as described in "Weld Backings Come of Age" published in Welding Magazine published in June 1975 rather than expensive metal supports. Do.

Examples of such nonmetallic welding supports include heat resistant tapes as described in US Pat. No. 3,001,057 and US Pat. No. 3,138,863, or heat resistant ceramic tiles or glass materials as described in US Pat. No. 2,820,427.

The present invention relates to such a non-metallic (eg ceramic) welding support, where a conventional ceramic welding support has a working surface that is completely planar or has a single longitudinal groove formed. As shown in FIG. 1, the two base metal plates 10, which are relatively thick (for example, 12 mm or more), are slightly spaced apart from each other to perform welding from above. The molten welding material 11 formed in the V-shaped space defined by the slit portions 16 cut away by placing a conventional ceramic welding support 12 having a completely flat working surface 14 under the plate 10. (I.e., base material, filler metal, material). The welding material is first melted by the heat generated during the welding, and in turn causes the central portion of the ceramic support 12 to be melted. (The molten portions of the plate 10 and the welding tile 12 are indicated by dotted lines). As the ceramic material melts, a denser weld material moves the molten ceramic material, thereby moving it to the working surface of the ceramic tile, resulting in the formation of an undercut 20 in the base metal plate. When the molten metal and ceramic material is cooled and the ceramic support is removed, the undercut 20 remains undesirably in the welded joint.

Welding supports made of ceramic tiles with a single longitudinal groove are also used to prevent the formation of such undercuts that reduce the strength of the weld seam. As shown in FIG. 2, a welding support 22 made of ceramic tiles having a single groove 26 (indicated by a dotted line) formed on the working surface 24 is placed under the plate 10 to be welded to form a molten weld material ( 11) to hold. As described above, the molten welding material melts the welding support, so that the molten welding material and the molten ceramic material are flowed into the 26 so that no undercut or the like is formed at all.

However, such a conventional welding support has a deep and wide groove so as to sufficiently prevent the formation of the undercut, and undesirably large lower reinforcement 28 is formed. As such, when the lower reinforcement becomes too large, machining is required, which requires additional labor and cost.

The present invention provides a ceramic welded support formed with a groove that can reduce the size of the lower reinforcement portion while reducing the formation of the undercut. In addition, the present invention provides a welding support that allows the maximum thickness of the welding support to be positioned adjacent to the hottest welding section to minimize burn-through of the support, that is, melting of the upper support by the molten welding material.

The present invention provides a heat resistant welding support (preferably made of a hard ceramic material) having a W-shaped cross section. In particular, the present invention provides a heat resistance welding support having grooves parallel to each other formed on a generally flat and wide working surface, with a central projection between the grooves, and a generally flat plane portion on the outside of the groove. In a preferred embodiment of the present invention the welding support consists of a ceramic tile having two parallel planes, one of which is the working surface. In yet another embodiment, the welding support can be connected by a single-sided welding method in a continuous, flexible row that can respond regardless of the shape of the surface to be welded.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

3 shows a ceramic welding support 30 of the present invention, the welding support 30 having a generally flat working surface 32, which is generally parallel to each other. Grooves 34 (defined by groove side surfaces 34a, 34b and groove bottom 34c) are formed, with central projections 36 between them, and generally flat outer planes on the outside of the grooves, respectively. The part 38 is formed. In the case of the present embodiment, a second plane 39 is also formed which is generally parallel with the working surface 32. As will be described later, the entirety of the grooves below the upper surface 37 of the central projection 36 is equal to or larger than the entirety of the central projections on the groove bottom 34c.

In the case of the present embodiment, the entire groove is formed on the dotted line 40, the groove side surfaces 34a, 34b and the groove bottom 34c extending from the top surface 37 of the central protrusion 36 to the groove side surface 34a. It can be expressed by multiplying the total length of the two grooves by the polygonal area defined by. The depth of the groove is the vertical distance from the groove bottom 34c to the outer flat portion 38. The volume of the central protrusion 36 is a central protrusion in a polygonal area defined by the dotted line 4 extending through the groove bottom 34c, the left and right groove side 34b surfaces, and the top surface 37 of the central protrusion 36. It can be expressed by multiplying the length of (36). The height of the central projection 36 is the vertical distance from the dotted line 42 to the upper surface 37 of the round projection 36.

4 is a welded joint formed by single pass welding using the welding support 30 shown in FIG. 3 (primary welding is performed from one side of the plate to form a preliminary welded joint, and again from the same side) Welding to thicken the weld seam). Each of the two base metal plates 50 having relatively thick edges 52 and each having a relatively thick thickness is positioned slightly apart from each other, so that the central projections 36 of the welding supports are positioned between the plates when the welding supports are positioned under the plates. To match the gap.

The molten weld material 54 may be formed through conventional welding, such as submerged arc welding, which is held by the welding support 30 and the plate 50.

As the molten weld material flows down between the plates and contacts the welding support, the central projection 36 of the support melts and flows into the groove 34. As described above, since the entirety of the two grooves is preferably equal to or larger than the volume of the central projection, all the central projections to be molten can flow into the grooves without undesirably contacting the plate 50 so that the undercut Will not form. In addition, the volume of the molten welding material flowing to the lower surface of the plate is reduced due to the volume occupied by the central protrusion, so that the lower reinforcement portion is not excessive. The welding support made of ceramic melts itself while retaining the welding material 54, thereby forming a uniform and rounded weld seam having a thin rounded lower weld 54a and a uniform upper weld 54b upon cooling.

Between the welding support and the lower welding portion 54a, a resolidified glassy ceramic layer 56 is formed. (Figures 1 and 2 do not show the ceramic layer resolidified for simplicity of illustration). The use of the welding support of the present invention results in the formation of a complete welded seam with little or no subsequent work.

The welding support of the present invention may be supported adjacent to the plate to be welded by using a magnet or a clamp, for example, or may be self-supporting. Means for supporting the welding support is provided with a flexible heat resistant support plate 60 provided with an adhesive layer 62 on one side, and the support layer can be adhered to the support plate 60 by the adhesive layer. The support plate 60 can be bonded to the plate to be welded. When not in use during shipment or storage, a detachable protective liner may be attached to the adhesive layer portion to be bonded to the plate to be welded to protect the portion from dust.

Suitable flexible support plates and adhesives for use in the present invention include those described in US Pat. No. 3,372,852.

The welding support of the present invention can be manufactured using any heat-resistant material. For example, the welding support of the present invention is manufactured by providing a binder to a heat-resistant material such as woven glass fiber or particulate material (for example, sand). You can do it. In the practice of the present invention, the materials of choice include hard magnesia-alumina silica ceramics (particularly ceramic tiles) such as forsterite cordierite steatite. Any known method such as machining, casting, dry pressing or extrusion may produce the welding support of the present invention from the selected materials as described above. As a manufacturing method which can be used preferably, a dry crimping or extrusion method is mentioned.

A plurality of welding supports of the present invention can be used by attaching them in a row to a flexible heat resistance support plate. In this case, end portions of each support are formed to be linked to each other so that the support lines attached to the support plate can have flexibility. However, no matter what type of welding plate is attached to the support plate, the support column can be flexible to ensure its function accurately. US Patent Application No. 30,735, filed May 12, 1978, entitled "Method for Pivoting Hard Heat Resistant Tiles," and the same name, "Welding Supports Using Knuckle-Joint Tile Rows." U.S. Patent Application No. 905,153, filed with, discloses a method for forming a rigid welding support with flexible heat as described above.

When the welding support 30 of the present invention shown in FIG. 3 also has a square cordierite ceramic tile having a width of 33 mm and a thickness of 7.9 mm, the two parallel grooves 34 formed thereon are formed. The depth is 2.4mm, the width at the top is 5.6mm, the width at the bottom is 4.0mm, the width at the top of the central projection is 6.4mm, the width at the bottom is 9.5mm, and from the groove bottom to the top The height is 1.6mm. When the extension of 19 mm thickness was welded by the submerged arc welding method using the support of such a dimension, there was only an undercut mark, and a weld part having an underside reinforcement of 1.6 mm to 3.2 mm thickness was ideally formed. In the case of welding using a conventional support having a rectangular uniform groove having a width of 16 mm and a depth of 2.0 mm, a lower reinforcement portion of 3.2 mm to 4.8 mm was formed in contrast to the present invention. In addition, when welding was performed using a conventional support having a rectangular uniform groove having a width of 16 mm and a depth of 0.8 mm, excessive undercut was formed.

Claims (1)

In a heat resistant welding support having a generally flat and wide working surface, grooves 34 parallel to each other are formed in the working surface 32 with a central projection 36 between the grooves 34, and A two-row grooved welding support, characterized in that the outer side to form a flat portion (38).