JPS58128290A - Multicored coated electrode - Google Patents

Abstract

PURPOSE:To provide a multicored coated electrode which produces less spatters during welding by assembling plural pieces of metallic core wires for welding of small diameters having coating materials to one body. CONSTITUTION:Plural pieces of metallic core wires for welding of small diameters having coating materials 2 for making electric arc welding easy around mandrels 1 are assembled and bundled to provide a multicored electrode 3. Alternately, plural pieces of such metallic core wires 4 for welding are embedded in a coating material 5 without contact with each other to form a multicored electrode 6. Since the generation of the arc is stabilized and less spatters are produced by the use of such multicored coated electrode, welding workability and welding quality are maintained satisfactorily.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a coated arc welding rod.

Social demands for disaster prevention have become more acute in recent years as cities become more crowded and buildings become larger and taller.In particular, fires cause enormous human and material loss, so more reliable disaster prevention technology is required. has been done. In particular, in the construction field, welding methods for various connections, adhesives, and fixings are widely used when constructing, expanding, or renovating buildings, but spatter scattered during work can fall onto combustible materials and cause fires. From the viewpoint of disaster prevention, measures to reduce the amount of spatter generated or to prevent the generated spatter from scattering are desired. Among these, the former measure is the most fundamental, and various attempts have been made. There are various possible causes for the occurrence of spatter, and they can be broadly classified into those related to welding methods, those related to welding rods, and those related to welding machines.

By the way, as a welding method, the so-called covered arc welding method using a covered welding rod is often used in industry because of its workability, versatility, and simplicity. It is well known to use a welding current as low as possible, or to improve the power supply and use a current with a high DC component. However, a decrease in welding current causes a decrease in welding speed and significantly reduces welding workability.

On the other hand, improving the power supply of existing welding machines requires considerable expense, and there are many difficulties from a cost perspective.

Additionally, attempts have been made to change the coating material of the welding rod since it has a large effect on spatter generation behavior, but this may reduce various weldability properties other than spatter generation.
From a practical standpoint, there is a lot of room for Ushida Yoko 1.

An object of the present invention is to provide a coated arc welding rod that can significantly reduce the amount of spatter generated during welding, in place of the prior art described above.

In other words, existing coated arc welding rods have a so-called single-core structure in which the surface of one metal core wire is coated with a coating material.
In the present invention, the materials and components of the coating material and core wire are the same as those of existing welding rods, but the structure is such that the metal core wire is made into a single core and a multicore body, and the coating material is present around the multiple cores. There are characteristics. When converting an existing single-core welding rod into a multi-core welding rod, if the total cross-sectional area of the metal core parts is made the same, the cross-sectional area of the multi-core wire will be smaller than the cross-sectional area of the single-core wire; The droplets of molten metal (hereinafter abbreviated as droplets) can also be made smaller, and at the same time, the arc force due to the individual arcs formed at this time is also smaller, and the scattering of the droplets tends to be smaller. In addition, with single-core wires, the coating material vaporizes or becomes a mist around a thick arc or thick droplet column, creating a chemically and electrically stable atmosphere, but with multi-core wires, the coating material vaporizes or becomes a mist. The coating material can exist dispersedly within a thick arc flow or a thick droplet column, so to speak.
The welding arc and droplet transfer are significantly stabilized, thereby significantly reducing the amount of spatter.

As described above, by increasing the number of cores, it is possible to reduce the total amount of spatter generated and also to reduce the size of individual spatter, which significantly reduces the chance of fire outbreak even when spatter scatters on combustible materials. can be done.

The present invention will now be described in detail with reference to the accompanying drawings.

[Example 1] As shown in Fig. 2, a multi-core welding rod 6 was manufactured by bundling seven coated welding rods each having a diameter of 1.2z, and this and the conventional welding rod shown in Fig. 1 were manufactured. An experiment was conducted to compare the amount of spatter generated with a single-core welding rod 3'. 1' is a metal core, and 2 and 2' are coating materials, respectively. The welding rod used here is a rod type for mild steel welding, and corresponds to JISD4303, and the core metal composition is c.
O, 08%, Mn 0.35%, Si 0.09%
, pO, 014%, SO, 012%, and the balance is Fe. The coating material is lime and titania based and contains about 30% or more of titanium oxide.

Here, the multi-core welding rod shown in FIG. 2 was manufactured so that the total cross-sectional area of each mandrel 1.1.1 was the same as the area of the single-core mandrel 1' shown in FIG. The welding machine is a double flow type and the welding current is 130
A. Welding position is downward. 5 welding rods each 650L long
During continuous bead welding of ordinary steel plates, all spatter scattered around was collected and weighed. Since the actual length of the welding rod consumed varies somewhat depending on the fitting, we compared the spatter amount per unit of consumable rod length, which is the total amount of spatter divided by the total length of the consumable rod. .

As a result, as shown in Table 1, the welding rod 6 of the embodiment shown in FIG. The particle size of sputter tends to become smaller. In the case of multi-core welding rods, welding was possible at almost the same speed as with single-core rods, and the quality of the deposited metal was comparable to that of single-core rods.

Table 1 [Example 2] Using the core metal 4 and coating material 5 having the same components or materials as in Example 1, as shown in FIG. A multicore welding rod 6 in which seven pieces of gold 4 were embedded was manufactured, and the amount of spatter generated was investigated using the same welding conditions and evaluation method as in Example 1.

Also in this case, the total cross-sectional area of the mandrel was made to be the same as the mandrel area of the single mandrel 6' shown in FIG. 1 used for comparison. As a result, the welding rod 6 shown in Fig. 6 has a spatter generation rate equivalent to the length of the consumable rod! l) 0.054
y/cm, about 35% of that of the single core type of Example 1.
The amount generated was small. The size of the spatter was the same as in the case of the welding rod shown in FIG.

[Example 3] Using a mandrel and a covering material having the same components or materials as in Example 1, a diameter of 0.73 r was used in the covering material without contacting each other.
A multicore welding rod having a structure in which 19 trmB mandrels were embedded was manufactured, and the amount of spatter generated was investigated using the same welding conditions and evaluation method as in Example 1. As a result, the amount of spatter generated by the welding rod of this example was 0.04317 am per unit rod length, which was about 48% less than that of the single core type of example 1, and less than that of example 2. I found out. As the number of core wires increases, the amount of spatter generated tends to decrease.

As is clear from the above embodiments, according to the multi-core coated arc welding rod of the present invention, by increasing the number of core metals, (1) arc generation is not only stabilized and the amount of spatter generated is reduced; The size of the spatter is also reduced, and even if it is scattered, the risk of fire outbreak is reduced.

(2) It has the effect of maintaining welding workability and welding quality similar to conventional welding rods.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a conventional example, FIG. 2 is an explanatory diagram of one embodiment of the multi-core coated arc welding rod of the present invention, and FIG. 3 is an explanatory diagram of another embodiment of the present invention. 1.4 Two-core metal, 2,5: Coating material, 3.6: Welding rod. Figure 1: 219 No. 3I￥l Continued from page 1 ■Applicant Kajima Corporation 2-7 Motoakasaka-chome, Minato-ku, Tokyo

Claims (1)

[Scope of Claims] 1. A multi-core coated arc welding rod comprising a plurality of small-diameter welding metal core wires having a coating material on the surface that facilitates electric arc welding. 2. A multi-core coated arc welding rod, characterized in that a plurality of small-diameter welding metal core wires are embedded and twisted in a coated material that facilitates electric arc welding without coming into contact with each other.