JPS58188576A - Electrogas welding method - Google Patents

Abstract

PURPOSE:To improve the weldability of vertical electrogas welding, by providing a bead forming groove which expands downward to a sliding strap used for the surface of a material to be welded and controlling the ascending speed of the sliding strap according to the detected value of wleding current. CONSTITUTION:A bead forming groove 13 of a sliding strap 4' is expanded downward in the width and depth of the groove 13. Molten metal 3 and molten slag 16 are formed among a stationary strap 5, the strap 4' and a base material 1 by melting of a flux cored wire 18 and a glass tape 6. The slag 16 forms front and rear slags 17, 17' on progression of the welding. When the molten slag 16 on the molten metal 3 increases to the amt. larger than a correct amt., extension l decreases and welding current rises higher than reference current; therefore, the current is regulated by increasing the ascending speed of the strap 4'. If the amt. thereof is smaller than the correct amt., the ascending speed is decreased. The slag 16 is thus controlled to the correct amt. and the normal vertical electrogas welding is accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrogas welding method with improved weldability.

In electrogas welding, as shown in Fig. 1, the base materials 1 and 2 to be welded are arranged facing each other with a predetermined gap 21, and a long fixed dowel 5 (generally A short sliding abutment 4 is applied to the front side, and a welding flux-cored wire 18f is fed from the torch 10 into the space surrounded by the base metal and the abutment, and a welding flux-cored wire 18f is placed between the base metal and the torch. A voltage is applied to generate an arc 2o from the tip of the wire 18, and a shielding gas is supplied from the gas supply port 11 of the sliding seat 4, and the arc heat damages the groove surface and the wire 18.
The molten metal 15 and molten slag 16 generated by the melting are collected in the groove 21, and the sliding abutment 4 and bath welding torch 1o are moved in accordance with the surface of the molten metal Me rising as the melt progresses.
to perform vertical advancement welding. When the groove base materials 1 and 2 are flat, the welding torch 10 is vibrated in the direction of the arrow B in the direction of the plate thickness using the vibration setting 9 to form weld metal stripes 6 on the groove 21 to obtain a good welding result. get.

How to apply an excessive amount of Minato molten slag 16 on the surface of this electrogas welded Fi molten gold K1415 from the start to the end of welding.
It is important to maintain the That is, in electrogas @ welding, a flux-cored wire is used, and the slag forming agent in the flux filled in the wire melts during welding and becomes slag.
6 is interposed between the sliding abutment 4 on the front side and the weld metal 3, solidifies into a slag 17, and forms a good bead and the sliding abutment 4
On the surface side, the slag forming agent in the flux and the glass tape 6 sandwiched between the weld metal 5 and the base metal 1.2 melt, and the slag forming agent in the flux melts, and the The slag 17' intervenes and contributes to the formation of beads on the backing body.

Further, the arc generated between the molten metal 15 and the wire 18 spreads the molten slag 16 by the arc force, thereby maintaining the arc generation. In order to obtain a good welding result, it is essential that the thickness of the molten slag 16 be maintained at an appropriate level. In other words, the molten slag 1 that forms on the surface of the bath metal during electrogas welding greatly affects the state of arc generation, and if the amount of molten slag is abnormally large, it may result in slag welding, or the spread of the arc may deteriorate, resulting in poor bead shape. This will result in poor penetration, and in extreme cases, it will be impossible to continue welding.

This flux-cored wire is quality-controlled so that the filling rate of slag 1tVi flux is constant, and the groove shape of the sliding butt and body fixing pad is constant regardless of the thickness of the base material. Therefore, the slag ′j# consumed as slag on the front and back sides of the bead is the same. On the other hand, even if the groove width and gap (G) for each plate thickness are the same, if the plate thickness changes, the cross-sectional area (
-) changes, and as the cross-sectional area increases, more slag-forming agent is supplied in the flux, and the slag-forming agent supplied in excess of the required amount is deposited as molten slag on the bath molten metal. The amount of molten slag in this bath should be reduced as much as possible/fr
In order to maintain the stability, it is possible to prepare flux-cored wires with different flux filling rates for each change in the bevel, but it is impossible to prepare each hinoki wire. Therefore, even if a suitable ori-layer is made, it is almost impossible to select and replace any desired wire each time the plate thickness groove changes at the welding stage.

Therefore, by using Yuzu wire, even if the groove shape changes, or even if the groove cross section changes temporarily due to a bad groove shape, a constant molten slag level can be maintained and the result is always good. It was hoped that a new electrogas welding method would be developed.

The present invention is a book that was created in view of the above-mentioned actual situation, and its gist is that a metal with a groove shape for forming a bead expanding downward is used as a sliding metal for electrogas welding. Then, the welding current is detected, the detected current value is compared with a preset reference current value, and when the detected current value is greater than the set reference current value, the trolley running speed is set to be lower than the rising speed of the molten metal. This is an electrogas welding method in which the bath molten slag cap is adjusted at high speed, and when the detected current value is smaller than the set reference current value, the trolley running speed is controlled to be slower than the rising speed of the molten metal. Tsumugi The present invention focuses on the fact that in electrogas welding, when the welding current is higher than the set reference current value, the cart rises at high speed. We focused on the fact that the lid changes depending on the shape of the bead-forming groove of the sliding stopper, and the shape of the bead-forming groove of the sliding stopper is made to expand downward. When the welding current becomes larger than the set standard 1' flow value, the molten metal is temporarily lifted faster (increasing the speed) to temporarily increase the amount of molten slag flowing out. The amount of molten slag on the N surface is returned to a predetermined amount. As a result, the molten slag of the Qr standard can be maintained at all times, and a very good bath welding result can be obtained.

Next, the present invention will be explained in detail together with a conventional method using the drawings. First, FIG. 1(a) is a cross section showing the ridges of electrogas welding, and FIG. 1(b) is a plan view of the apical part thereof. FIG. 2 is a detailed view of the first side of the tube section showing the electrogas welding of the present invention, and FIG. 6 is a perspective view of a sliding seat used in the present invention. Electro gas bath welding is performed on the base material 1 as shown in Figures 1 and 2.
, 2, apply a same foot pad 5 on the back side with a glass tape 6 in between, and apply a sliding pad 4' on the front side to form a groove to be welded. Reference numeral 4 denotes a traveling carriage 8 which moves up along with the welding torch 10 as welding progresses.

In welding, an arc is generated between the flux-cored wire 18 and the molten metal to bathe the groove surfaces of the base metals 1 and 2 and the flux-cored wire 18, and a bead is formed in the groove 21 with the weld metal 5. Proceed with welding. 7 is a chip. Meanwhile, the welded part is connected to the gas supply port 11 provided at the top of the sliding butt 4.4'.
From CO! Gas is supplied to shield the welding area, and the sliding contacts 4 and 4' are supplied and drained as shown by the arrows using a cooling water vibro 12 to cool the sliding contacts and perform bath welding.

Welding dust during electrogas bath welding is caused by groove 2 of base material 1.2.
As the welding progresses, the molten slag 1.6 generated by the slag forming agent contained in the flux in the wire and the glass tape 6 is exposed to the surface of the molten metal 150 in the welding process. The molten slag is consumed as slag 17 interposed in between, while maintaining a thickness that does not interfere with welding. If the thickness is maintained at a level that does not interfere with welding, stable welding current and heavy welding pressure will result, resulting in a defect-free weld. However, if the amount of molten slag 16 exceeds the amount consumed as the amount of slag 17 on the bead surface and becomes thick enough to interfere with welding, the melting on the groove surface will decrease and the width of the surface bead will become narrower. This will result in a bead with insufficient penetration.In extreme cases, slag welding will occur and welding will eventually become impossible.

Further, the present invention will be explained using FIG. 2.3.

As shown in FIG. 3, the bead forming groove 16 of the sliding butt 4' used in the present invention shown in FIG. A major feature is that it is large. In addition, as mentioned above, the molten slag 1
6 is generated by melting the flux-cored wire 18 and the glass tape 6, and the molten slag 16 is consumed as front and back slags 17, 17' as welding progresses, resulting in #fusion l! 4.When the amount of molten slag 16 in the improved bath exceeds the appropriate value, when the rising speed of the molten metal is faster than the rising speed of the trolley, the extension (wire protruding length) t
As soon as the welding current becomes higher than the set reference current, and at the same time the welding current becomes higher upstream than the set reference current, the trolley travel speed Ifi increases to 80.
I was cut off by a high-speed pigeon. Therefore, the sliding allowance 4 also rises quickly, and while the molten slag 16 is consumed, 11j! 1
3 widens, the amount of molten slag 16 flowing out increases, and the amount of molten slag 16 deposited on the surface of molten gold 15 decreases, and the extension t also becomes longer, returning the welding current to the original current. When the abnormality of the molten slag 16 is restored to normal as described above, the slag 17 formed on the bead surface is periodically formed into protruding slags 18. On the other hand, when the molten slag 16 flows out, the extension becomes longer and the fg contact current becomes lower, and at the same time, the traveling bogie becomes slower and the rise of the sliding cushion 4' becomes slower, resulting in less slag consumption. As a result, the molten slag 16 returns to its proper strength, and normal welding can be continued by repeating this process.

The electrogas welding method of the present invention and its effects are illustrated in Fig. 4.5. Fig. 4 shows the relationship between the welding current and the wire protrusion (extension), and the feeding speed of the wire 18 is kept constant. This is the case when As is clear from this graph, the welded portion Mt(A) changes as the protrusion length t (extension) of the wire changes.

That is, if the rising speed of the molten metal is faster than the rising speed of the trolley, the wire protrusion length t (extension) will also be shortened, and the tr flow will be reduced. Figure 5 shows changes in the running speed of the bogie as the welding current changes, and when it is detected that the welding current has become higher than the set reference current value, the control device switches the running speed of the bogie to linear speed, increasing the speed. On the other hand, as the current value decreases, the traveling speed of the bogie also decreases. In this manner, by flowing the molten slag during high-speed rise, the adhesion of the molten slag 16 on the common metal surface is always maintained properly, and good bath contact can be maintained from the beginning to the end.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the outline of electrogas bath welding (1
) is a part of l! FIG. 3B is a plan view of FIG. Fig. 2 is a partially cross-sectional side M view showing the electrogas bath welding method of the present invention, and Fig. 3 is a side M view showing the electrogas bath welding method of the present invention.
4 and 5] are graphs for explaining the movement 11. In Zukaku, 4.4' is Suri-1 butt and 16 is molten slag. Applicant Nippon Steel Welding Industry Co., Ltd. Representative Patent Attorney Minoru Aoyagi Fig. 1 (a) (b) Fig. 2 Fig. 4 - Fiber protrusion length mm Fig. 5 □I Flash II#lI

Claims (1)

[Claims] In the vertical electrogas welding method that uses a sliding dowel on the surface of the material to be welded, a sliding dowel with a groove shape for forming a bead that expands downward is used, and the welding current is detected, The detected current value is compared with the set reference current value, and if the detected current value is greater than the set reference current value, the trolley running speed is set higher than the rising speed of the molten metal, and the detected current value is set to the set reference current value. An electro gas welding method characterized by controlling the traveling speed of the cart to be lower than the rising speed of the molten metal to adjust the molten slag lid when the molten metal rises.