JPS6015070A - Penetration welding method and backing strip for penetration welding - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a Uranami welding method and a backing material for Uranami welding used to carry out the Uranami welding method.

Uranami welding is a welding method in which a backing material is placed on the back side of the groove and arc welding is performed from the front side to form a bead on the back side of the groove. In wave welding, it is common to use a melt-type backing material made of fluffx or the like, or a metal backing material such as a water-cooled copper plate.

By the way, when the above melting type backing material is used, the surface of the backing material is damaged by melting after one welding, so it is necessary to use a new backing material for each welding operation, which is uneconomical. It has the disadvantage of being. Furthermore, when this type of backing material is used, molten slag, generated gas, etc. may be present on the back surface and suppress the temperature of the molten metal, and if the root gap of the groove is too narrow ( For example, if it is smaller than 2 dragons), there is also a problem in welding that it becomes difficult to form a stable back wave.

On the other hand, when a metal backing material such as a water-cooled copper plate is used, although it can be used repeatedly, it has the drawback that the overall weight is extremely large and its handling is inconvenient.

This invention was made in view of the above, and its purpose is to provide a method for welding uranami that is capable of forming a stable uranami bead even when the root gap is narrow, and that has good workability. Our goal is to provide the following.

Another object of the present invention is to provide a backing material for Uranami welding that can be used repeatedly, is lightweight, and is suitable for carrying out the above-mentioned Uranami welding method.

The uranami welding method of the present invention, which achieves the above object, is a uranami welding method in which a backing material is placed on the back side of a groove and arc welding is performed from the front side of the groove. The casing has a bottom and a plurality of ceramic backing blocks housed in the backing block, and grooves extending in the longitudinal direction are formed on the top, bottom, right and left sides of the backing block, and the casing has a bottom and both sides extending upward, and engagement protrusions that fit into grooves provided on both sides of the backing block to hold the backing block are provided on both sides, and the groove is further provided with engaging protrusions for holding the backing block. It is characterized in that a glass fiber sheet material is interposed between the backing material and the backing material.

Further, the backing material for uranami welding of the present invention used to carry out the above-mentioned uranami welding method comprises a casing and a plurality of ceramic backing blocks housed in the casing, has concave grooves extending in the longitudinal direction on each of its top and bottom, left and right sides, and the casing has a bottom and both sides extending upward from the bottom, and these both sides are provided on both sides of the backing block. It is characterized by having an engaging protrusion that fits into the groove and holds each backing block.

Next, specific embodiments of the present invention will be described in detail with reference to the drawings.

In Fig. 1, 1.2 indicates the base material to be welded, 3 indicates the groove formed between both ends of the base materials 1.2, and a backing material 4 is provided on the back side of the groove 3. is located. In this case, the backing material 4 consists of a plurality of backing blocks 5 and a casing 6 that accommodates the backing blocks 5. In addition, between this backing material 4 and the base material 1.2, there are
It is assumed that two glass fiber sheet materials, that is, fiber tapes 7 are interposed, and are pressed into contact with the backing material 4 via the fiber tapes 7 of the base material 1.2.

As shown in FIG. 2, the backing block 5 has a substantially square cross section, and grooves 8a, 8a, 8b, 8b are formed on each of its upper, lower, left and right side surfaces with an arcuate cross section and extending in the longitudinal direction. has been done. In this case, the upper and lower pair of grooves 8a, 8a have the same dimensions, and the left and right pair of grooves 8b, 8b have the same dimensions and are slightly larger than the grooves 8a, 8a. The dimensions of the groove 8a or 8b located at the bottom of the groove 3 can be changed depending on the size of the root gear. Further, each corner of the backing block 5 is chamfered 9 to prevent the backing block 5 from coming off from the corner. Furthermore, a through hole 10 is formed in the center of the backing block 5 and extends through the backing block 5 in the longitudinal direction. (not shown) and, if necessary, cool the backing material 4 during welding to prevent it from overheating, or cool the entire backing material 4 after welding is completed. It plays a role in making things more convenient. In addition,
Water or gas is passed through the cooling pipe, but in some cases, the gas may be passed directly into the through holes 10 without using the cooling pipe. Further, by providing the above-mentioned through-holes 10, even if a crack that starts and grows from the surface of the backing block 5 occurs during handling of the backing material 4, this crack can be removed by the through-hole 10. It becomes possible to stop at a certain point, which acts as a so-called stop hole.

The backing block 5 is made of ceramic such as silicon nitride or silicon carbide, which has high hardness, high melting point, and large heat capacity. The type of ceramic is not particularly limited, but since the backing block 5 is subjected to localized rapid heating during welding, it may be used to prevent damage due to thermal stress at that time. It is preferable to use silicon nitride, which has a low coefficient of thermal expansion and high strength at high temperatures. In addition,
In order to alleviate the thermal stress generated during welding as mentioned above,
As shown in FIG. 3, grooves 11 and 11, which are slightly deeper than the grooves 8a and 8b, may be provided on both sides of the grooves 8a and 8b.

In addition, the above-mentioned backing block 5 specifically has dimensions of about 5011 mm in length and width, and lengths of 50 mm and 100 mm.
There are three types of backing tools 5, 1501 and 1501, and a plurality of these backing blocks 5 of different lengths are combined to adjust the overall length according to the required dimensions of the target work. In this case, the grooves 8a and 8b are formed on all the side surfaces of the backing block 5.
This is so that it can be used as a so-called backing part that comes into contact with the back surface of the groove 3. These grooves 8a, 8b
Specifically, as shown in Fig. 4, the grooves 8a, 8a on the top and bottom sides are set to have a depth of 211 mm and a width of W 8 mi+, and are used when the root gap is 4 fins or less. The grooves 8b and 8b have a depth of d2 and a width of 12 mm.
It is recommended to be used when the root gap is 4 cm or more. In addition to this, the depth d is 3fi and the width W is 1.
It is possible to make the overall size as large as 5m,
Further, all the grooves 8a and 8b may have the same shape and size.

The backing block 5 described above is housed and held in a casing 6, as shown in FIGS. It has a substantially U-shaped cross section with portions 14 and 15, and has a desired length. A pair of engagement protrusions 16.17 are formed at the upper ends of both sides 14.15 of the casing 6, and are arranged to face each other.

The engaging protrusions 16 and 17 have an arcuate cross section similar to the recess Ij8b of the backing block 5 described above, and the interval between them is determined when the backing block 5 is placed inside the casing 6. , are selected so that the respective engaging protrusions 16.17 can press into contact with the surfaces of the recesses 168b and 8b due to the elasticity of the side portions 14.15.

Using the backing material 4 and fiber tape 7 as described above,
Gas-shielded arc welding is performed from the groove surface side in the arrangement shown in FIG. 1 above. In this case, 100% CO2 may be used as the shielding gas, or 80% CO2 may be used as the shielding gas.
Ar+2o%coQ may also be used. The welding results are shown in FIG.
) shows the welding results when both are used together. As is clear from the figure, when the fiber tape 7 and the backing material 4 are used together, it is possible to obtain a good back wave beat. Moreover, FIG. 8 shows welding results when both are used in combination and the root gap of the groove is variously changed. In the same figure, (a) is the second root gap, (b)
(C) shows the case of 4u+, and (C) shows the case of 6 cranes, but it is clear from the figure that a good Uranami beat can be obtained in any root gap. In the above test, the grooves 8a and 8b had a depth of d3m and a width of W.
15 +u is used.

Although one embodiment of the present invention has been described above, the Uranami welding method and Uranami welding material of the present invention are not limited to the above embodiment, and can be implemented with various modifications. be. For example, as the welding method, it is possible to employ other arc welding methods such as a gas-shielded arc welding method, a shielded arc welding method, and the like. Further, the cross-sectional shape of the grooves 8a and 8b of the backing block 5 is not limited to the arc shape described above, but can be changed in various ways. In this case, it goes without saying that the cross-sectional shape of the engaging projections 16, 17 of the casing 6 should be selected so that they can fit into the grooves 8a, 8b.

The uranami welding method and backing material for uranami welding of this invention are constructed as described above, and therefore, according to the method of this invention, a non-melting type ceramic backing block is used. It is possible to form a stable uranami beat even when the root gap of the groove is narrow, and since most of the backing material is ceramic, the entire material is lightweight and has good workability. becomes. In addition, since the backing material for uranami welding of the present invention uses durable ceramic, it can be used repeatedly and is lightweight. It is possible to implement the wave welding method efficiently.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an embodiment of the Uranami welding method of the present invention;
2 to 6 are diagrams showing an embodiment of the backing material for uranami welding of the present invention, and FIG. 2 is a cross-sectional view of the backing block;
Fig. 3 is a cross-sectional view of the main part showing a modification example, Fig. 4 is a cross-sectional view of the main part showing the shape of the groove, Fig. 5 is a perspective view of the casing, and Fig. 6 is a cross-sectional view of the main part showing the shape of the groove. Fig. 7 is a partially cutaway perspective view of the block accommodated, and Fig. 7 is a diagram showing the metal structure of the welded part by the method of the present invention, (a) is when only the backing material is used, and (b) is when only the backing material is used. Fig. 8 is a diagram showing the metal structure of the welded part when the root gap is variously changed in the method of the present invention.
(a) Root gear 2m, (b) 4 prizes ■, (C)
shows the cases of 6 irises. 3... Bevel, 4... Backing material, 5... Backing block, 6... Casing, 7... Sheet material, 8a, 8b
...concave groove, 13...bottom, 14.15...side,
16.17...Engagement protrusion. Figure 1 Figure 2 Figure 3 Figure continued from page 1 0 Inventor Makoto Yamashita 3-1-1 Higashiyosaki-cho, Chuo-ku, Kobe City Kawasaki Heavy Industries, Ltd. Kobe Factory 0 Inventor Iwai Tetsuo Inside Kawasaki Heavy Industries, Ltd. Kobe Factory, 3-1-1 Higashiyosaki-cho, Chuo-ku, Kobe City0 Inventor Shinmei Hirai Inside Kawasaki Heavy Industries, Ltd. Kobe Factory, 3-1-1 Higashiyosaki-cho, Chuo-ku, Kobe City

Claims (1)

[Claims] 1. In the Uranami welding method in which a backing material is placed on the back side of the groove and arc welding is performed from the front side, the backing material is placed in a casing and a plurality of pieces housed in the casing. The casing has a bottom part and both sides extending upward from the bottom part. At the same time, engaging protrusions are provided on both sides of the backing block to fit into grooves provided on both sides of the backing block to hold the backing block, and the groove and the backing material An uranami welding method characterized by interposing a glass fiber sheet material between. 2. Consisting of a casing and a plurality of ceramic backing blocks housed within the casing, the backing blocks each having grooves extending in the longitudinal direction on each of its upper, lower, left and right sides; It has a bottom portion and both side portions extending upward from the bottom portion, and the both side portions have engaging protrusions for fitting into grooves provided on both sides of the backing block and holding each backing block. A backing material for Uranami welding characterized by the following.