JP3004462B2 - Backing material for single-sided arc welding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backing for single-sided arc welding comprising a refractory and / or a glass fiber molding used for gas-shielded arc welding of steel using a solid wire or a flux-cored wire. It is about materials.

[0002]

2. Description of the Related Art As a backing material for single-sided welding in gas shielded arc welding, (a) an inorganic glass fiber molded product (Japanese Patent Publication No. Sho 50-3) has been conventionally used.
No. 5488, etc.), and (b) a refractory molded body (JP-B-63-7)
877, etc.) or (c) a laminate in which a glass fiber molded article is added to the upper part of a refractory molded article (JP-B-63-7876).
No.) and other fire-resistant backing materials are commonly used, and water-cooled copper metal has been used for a long time.

[0003] In the latter single-sided arc welding method using a copper metal, unless the welding conditions, the groove processing accuracy of the workpiece to be welded, and the method of attaching the back metal are sufficiently controlled, Cu in the weld metal is required.
Incorporation causes welding defects such as material change and cracks,
In addition, there is a problem that handling of the cooling water piping and the like is complicated. For this reason, it is not actually applied particularly to one-side welding by a welding robot.

When the former refractory backing material is applied to one-sided arc welding by a welding robot, it has the following problems.

That is, when a welding robot automatically performs one-side welding of a butt joint made of steel, the groove route gap fluctuates from a design value due to the processing accuracy and assembly error of the member. It is necessary to detect the gap and adjust welding conditions such as the weaving width and welding speed taught in advance according to the detected value.

As a method of detecting the groove root gap, a storage / reproduction type arc welding robot provided with a sensing means for detecting a work position is used, for example, a method described in Japanese Patent Application Laid-Open No. 2-205266. There is.
FIG. 1 is a flowchart thereof, and FIGS. 2 to 5 are explanatory diagrams of the teaching operation.

In this case, it is necessary to electrically conduct between the welding wire to which the sensing voltage is applied and the groove surface and the backing material. However, the above-mentioned sensing cannot be performed because the backing material made of a conventional refractory molded body such as ceramic and flux or a glass fiber molded body is an insulating material.

However, as a simple method of providing conductivity between the backing material and the groove surface, a backing material is attached to the upper surface of the backing material with an iron plate interposed therebetween, and after detecting the groove root gap, A method of removing the iron plate and reattaching the backing material is conceivable, but the trouble of attachment and detachment is complicated and impractical.

The present invention has been made in view of such circumstances, and provides a method which can easily realize single-sided arc welding by a storage / reproduction type arc welding robot having a sensing means. It is the purpose.

[0010]

Means for Solving the Problems The present inventor has made various studies on the backing material in order to solve the above-mentioned problems, and as a result, has completed the present invention.

That is, the present invention provides a groove root gap.
-Side arc welding by a memory-reproducing welding robot that detects an arc
In the backing material used for contacting, a thin layer made of a conductive substance is formed on the groove-side surface of a refractory molded body such as ceramic or flux and / or a glass fiber molded body across the groove, and the base material is formed. And the thin layer is made of A
one or two or more layers of a low melting point metal or an alloy of the low melting point metal composed of l or Zn and having a total thickness of 0.1 to 200 μm, and a layer composed of Fe, Cu, Ni, Ti or Cr One or more layers of a high melting point metal or an alloy of the high melting point metal having a total thickness of 0.1 to 50 μm
m and a thickness of 0.1 to 1 μm made of C (carbon)
And a backing material for single-sided arc welding, characterized in that the backing material comprises at least one layer selected from the group consisting of:

Hereinafter, the present invention will be described in more detail.

[0013]

The reason that it is impossible to detect the groove root gap by the memory / reproduction type welding robot with the single-sided welding backing material composed of the conventional refractory molding or glass fiber molding is as follows.
This is because only insulating materials are used.

[0014] On the other hand, the present invention provides a welding wire in which at least a groove root gap of a backing material for single-sided welding in gas shielded arc welding is to be detected by the welding robot. The main point is to electrically conduct between the backing material and the groove.

Examples of such a conductive substance include: (1) one or more of low-melting metals such as Al and Zn or alloys of the low-melting metals (metals or alloys which are easy to volatilize or burn); ) One or more of high-melting metals such as Fe, Cu, Ni, Ti, Cr and alloys of the high-melting metals (metals or alloys which hardly volatilize or burn), (3) C (carbon) (for example, graphite) )). These are non-hygroscopic.

The thickness of the thin layer of these materials is 0.1 to 200 μm in total in the case of a layer of a low melting point metal or an alloy of the low melting point metal, and a thickness of a high melting point metal or an alloy of the high melting point metal. The total thickness of the layer is 0.1 to 50 μm, and the thickness of C is 0.1 to 1 μm.

The preferable range of the thickness of the thin layer made of the conductive material is that when the thickness is less than the lower limit value, the electrical conductivity is insufficient, and when the thickness exceeds the upper limit value, the material penetrates into the weld metal and the material is invaded. This is because there is a risk of causing thermal deterioration, requiring reworking in dimensions and shape, and deteriorating slag releasability and back bead appearance.

As a method of adding the conductive substance to the refractory molded body or the glass fiber molded body, for example, a method of attaching or mechanically fixing a foil-like material, a method of spraying, and a method of applying a powder. After mixing with a binder such as water or alcohol, a method of drying and applying (or baking) or the like may be used.

Of course, a backing material in which a thin layer of a conductive substance is added to the surface of a refractory molded body or a glass fiber molded body is particularly suitable for one-sided arc welding by a welding robot, but is also applicable to other welding methods. It goes without saying that it can be applied.

[0020]

Next, the characteristics of the embodiments falling within the scope of the present invention will be described.

[0021]Example 1  Derivation of the shape and dimensions shown in FIG. 6 (overall view) and FIG.
Electroconductive aluminum foil (thickness 10μm) for refractory molding
A backing material was prepared and attached to the back of the base material
After that, first open using a memory and regeneration type arc welding robot.
After detecting the root gap,
One-sided welding by contact was performed.

The base material is JIS G 3106 SM49
OA was used and the groove shown in FIG. 8 was used. Root gap G: 3 to 10 mm, length:
At 600 mm, steel tabs were attached to both ends of the groove.

The welding wire includes a carbon dioxide gas shielded arc welding solid wire (JIS Z3312 YGW1).
2) (diameter 1.2 mm) was used. 10 mm (thickness) x 30 mm (width) x 600
The dimensions are mm (length) and the components are SiO ₂ 56%, Al ₂
A material containing 30% of O _{3 and} 10% of MgO was used.

The detection of the root gap by the storage / reproduction type arc welding robot was carried out at three points a, b and c in FIG. 6 by the method shown in FIG. 1 (sensing voltage 100 V).

The welding conditions were as follows: welding current: 220 A, arc voltage: 28 V, current type: DC, wire (+), shielding gas: CO ₂ gas, 25 l / min, welding posture: downward, torch rod: Weaving.

As a result of performing the test under the above conditions, in the first layer welding, a bead having a good appearance and shape without any welding defects on both the front side and the back side was obtained.

[0027]Example 2  Copper powder instead of aluminum foil as conductive material
Of about 1.0 μm applied over the entire length of the refractory surface
This material was produced. After attaching this to the back of the base material,
・ First of all, using a regenerative arc welding robot,
After detecting the gap, the gas shielded arc welding
One-sided welding was performed.

The base material and the groove shape were the same as in Example 1. However, the groove shape is the shape shown in FIG. 9, and the root gap G is 6 to 8 mm. The same refractory as the welding wire and the backing material as in Example 1 was used.

The detection of the root gap by the memory / reproduction type arc welding robot was performed at two points a and b in FIG. 6 by the method shown in FIG. 1 (sensing voltage 200 V).

The welding conditions were as follows: welding current: 200 A, arc voltage: 24 V, type of current: DC, wire (+), shielding gas: CO ₂ gas, 20 l / min, welding posture: downward, torch rod: Weaving.

As a result of performing the test under the above conditions, in the first layer welding, a weld having good bead appearance and shape without welding defects and slag removability was obtained.

[0032]

As described in detail above, according to the present invention,
It is possible to detect the groove root gap of the welding robot, and the effect of contributing to the enhancement of the efficiency of welding by the welding robot, labor saving, and promotion of high quality of the welded portion is great.

[Brief description of the drawings]

FIG. 1 is a diagram showing a flowchart of route gap detection by a welding robot.

FIG. 2 is a diagram illustrating a teaching operation of root gap detection by a welding robot.

FIG. 3 is a diagram illustrating a teaching operation of root gap detection by a welding robot.

FIG. 4 is a diagram illustrating a teaching operation of root gap detection by a welding robot.

FIG. 5 is a diagram illustrating a teaching operation of root gap detection by a welding robot.

FIG. 6 is a plan view showing the entire refractory molded body to which a conductive aluminum foil is attached.

FIG. 7 is a sectional view taken along the line AA of FIG. 6;

FIG. 8 is a sectional view showing a groove shape and dimensions used in Example 1.

FIG. 9 is a cross-sectional view showing a groove shape and dimensions used in Example 2.

[Explanation of symbols]

1 the welding robot torch 1a welding wire 2a first groove surface 2b of the second groove surface 3 groove root bottom PS sensing start position PT teaching position Q1 groove root position Q2 groove root location theta ₁ first groove surface Groove angle θ ₂ Groove angle of second groove surface W Groove root gap 4 Conductive substance (aluminum foil) 5 Refractory molded body 6 Aluminum adhesive tape

Continuation of the front page (56) References JP-A-64-15278 (JP, A) JP-A-2-205266 (JP, A) JP-A-62-260674 (JP, A) JP-A-57-139497 (JP) , A) Jiko 56-45759 (JP, Y2) JP-B 44-13811 (JP, B1) Joko 44-22348 (JP, Y1) (58) Fields surveyed (Int. Cl. ⁷ , DB Name) B23K 9/039 B23K 9/095 B23K 37/06

Claims (1)

(57) [Claims] 1. Storage and reproduction for detecting a groove root gap
Backing used for single-sided arc welding by die-type welding robots
In the material, a thin layer made of a conductive material is provided on the surface of the groove side of the refractory molded body such as ceramic or flux and / or the glass fiber molded body so as to extend across the groove and reach both base materials. The thin layer is made of one or two of a low-melting metal made of Al or Zn or an alloy of the low-melting metal.
At least one kind of layer having a total thickness of 0.1 to 200 μm and one or more layers of a high melting point metal made of Fe, Cu, Ni, Ti or Cr or an alloy of the high melting point metal And at least one layer selected from the group consisting of a layer having a total thickness of 0.1 to 50 μm and a layer of C (carbon) having a thickness of 0.1 to 1 μm. Characteristic backing material for single-sided arc welding.