JPH0218958B2 - - Google Patents

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 been increasing in recent years as cities have become overcrowded and buildings have become larger and taller.In particular, fires cause enormous human and material loss, so more reliable disaster prevention technology is required. ing. In particular, in the construction field, welding methods are widely used for various connections, adhesives, and fixations when constructing, expanding, or renovating buildings. This often happens, and from the perspective of disaster prevention, measures are desired to reduce the amount of spatter generated or to prevent the generated spatter from scattering.
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, but they can be broadly classified into those related to the welding method, those related to the welding rod, and those related to the welding machine. 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, the decrease in welding current is
This 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. In addition, there are attempts 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 other than spatter generation, so there is still room for consideration from a practical standpoint. many. 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 without any deterioration in weldability, in place of the prior art described above. That is, 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, but in the present invention, the materials and components of the coating material and the core wire are the same as those of existing welding rods. However, the metal core wire is composed of one central thin metal core wire and a plurality of thin metal core wires surrounding it, and The entire cross-sectional area of the metal core wire is made to be substantially the same as that of the metal core wire, and the coating material is provided around each of the plurality of thin metal core wires to integrate the whole. It is composed of In the present invention, by making the existing single-core welding rod multi-core, the cross-sectional area of each metal core wire is reduced without deteriorating the welding performance. The droplets of molten metal (hereinafter referred to as droplets) can also be made smaller, and at the same time, the arc force due to the individual arcs that are formed is also small.
The scattering of droplets also tends to become 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. Since the coating material can be dispersed in a so-called comprehensive thick arc flow or thick droplet column, the welding arc and droplet transfer are significantly stabilized, and the amount of spatter generated is thereby significantly reduced. As described above, by increasing the number of cores, it is possible to reduce the total amount of spatter generated and to reduce the size of individual spatter, which significantly reduces the chance of fire starting even when spatter scatters on combustible materials. can be done. Next, embodiments of the present invention will be described with reference to the accompanying drawings. Example 1 As shown in Fig. 2, each core is made of one coated welding rod with a diameter of 1.2φ and six surrounding it.
A multi-core welding rod 3 having a configuration of bundled together with books was manufactured, and an experiment was conducted to compare the amount of spatter generated between this and a conventional single-core welding rod 3' shown in FIG.
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.
Equivalent to JIS D4303, the core metal content is C0.08%,
The balance is Mn0.35%, Si0.09%, P0.014%, S0.012%
It is Fe. The coating material is lime or titania based and contains about 30% or more of titanium oxide. Here, each core metal 1, 1,
The total cross-sectional area of 1 was made to be the same as the area of the single-core metal core 1' shown in FIG. The welding machine is an AC type, the welding current is 130A, and the welding position is downward.
Five welding rods, each 350 liters in length, were bead-welded in succession on an ordinary steel plate, and all the spatter scattered around was collected and weighed. Since the actual length of the welding rod that was consumed varies somewhat depending on the trial number, the rod types were compared based on the amount of spatter per unit length of the consumable rod, 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 3 of the embodiment shown in FIG.
The amount of spatter generated is reduced by approximately 26%, and as shown by the sieve analysis, the particle size of spatter tends to become smaller. In addition, in the case of the multi-core welding rod, welding was possible at almost the same speed as in the case of the single-core rod, and the quality of the deposited metal was comparable to that of the single-core rod.

[Table] Example 2 A mandrel 4 and a covering substance 5 having the same components or materials as in Example 1 were used, and as shown in FIG. A multi-core welding rod 6 with a configuration in which a plurality of rods 4 are embedded with one central rod and six surrounding rods was manufactured, and the amount of spatter generated was investigated using the same welding conditions and evaluation method as in Example 1. did. In this case as well, the total cross-sectional area of the mandrel was made to be the same as the mandrel area of the single mandrel 3' shown in FIG. 1 used for comparison. As a result, welding rod 6 in Fig.
The amount of spatter generated is 0.054 per unit consumable rod length.
g/cm, which is approximately 35 g/cm higher than that of the single-core type in Example 1.
% generation amount was low. The size of the spatter was almost the same as that 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 plurality of mandrels each having a diameter of 0.73 mmφ were placed in the covering material as a whole as shown in Fig. 3 without contacting each other. A multicore welding rod with a structure in which 19 rods 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 welding rod of this example had a spatter generation rate of 0.043 per unit of consumable rod length.
g/cm, which is approximately 48 g/cm higher than that of the single-core type in Example 1.
% less than that of Example 2. As the number of core wires increases, the amount of spatter generated tends to decrease. As is clear from the above examples, according to the multi-core coated arc welding rod of the present invention, by increasing the number of core metals, (1) arc generation is stabilized, and the amount of spatter generated is not only reduced; The size of spatter is also reduced, and even if it scatters, the risk of fire outbreak is reduced. (2) It has the effect of maintaining welding workability and welding quality similar to that of 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: core metal, 2, 5: coating material, 3, 6: welding rod.

Claims (1)

[Claims] 1. A coated arc welding rod that has a coating material that facilitates electric arc welding on the surface of a metal core wire for welding, which has one thin metal core wire centered on the metal core wire and a plurality of core wires surrounding it. The structure is made of thin metal core wires, and the overall cross-sectional area of the plurality of thin metal core wires is made to be substantially the same as that of the metal core wire, and the plurality of thin diameter metal core wires are A multi-core coated arc welding rod characterized in that the above-mentioned coating substance is present around each of the metal core wires, and the whole is integrated.