JPS591155B2 - coated arc welding rod - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coated arc welding rod in which the performance of the welding rod is further improved by improving the dry cracking prevention and falling-off resistance of the coating material.

Coated arc welding rods are made by adding a binder to the welding flux raw material and kneading it, then applying the kneaded coating agent to the outer periphery of the steel core wire, and then applying the applied coating agent to the welding rod. Dry at an appropriate temperature depending on the purpose.

It is manufactured through a process of removing moisture from the coating material. However, at manufacturing sites, especially at drying sites, efforts are expended to prevent the occurrence of drying cracks in coating materials. The cause of this dry cracking is that as the moisture in the coating evaporates, a thin layer of gelled adhesive film is formed on the surface of the coating. One of the reasons is that it occurs if the conditions are not appropriate, but I believe that there are many other factors that are intricately related. Therefore, at the manufacturing site, the drying temperature of the coating material is carefully controlled to prevent dry cracking, but the optimum drying temperature conditions also vary widely depending on the type of flux component and adhesive used, so it is difficult to completely control the drying temperature. However, it is not possible to prevent this dry cracking, and the final step is to check for defective products with dry cracking through sorting.

This dry cracking can cause extremely serious defects in welding, such as poor welding workability, pits, and blowholes, so it is necessary to carry out strict selection from this perspective. On the other hand, even if dry cracking does not occur, the welding rod can be transported during transportation. The coating may fall off. The direct cause is said to be due to the drying conditions, the bonding force between the fluxes, the bonding force between the core wire and the coating material, etc. Conventionally, attempts have been made to solve these dry cracking and prevention of falling off by researching flux components and adhesion agents, and finding the optimal drying conditions for coating materials, but these methods place a heavy burden on the site. Since there were some issues that could not be resolved satisfactorily with these measures, it was desired to eliminate the above-mentioned drawbacks by investigating the root cause of drying cracks and the like. The present invention was achieved by focusing on the technical aspect that the dry cracking and falling off are related to the particle size of the flux raw material, and the purpose of the present invention is to reduce the labor of the workers at the manufacturing site, and to , prevention of dry cracking of coating materials,
The purpose of the present invention is to provide a coated arc welding rod that improves drop-off resistance.
13-22% μ particles, 10% 30-60μ particles
The present invention is a coated arc welding rod in which a coating material obtained by adding a fixing agent to a welding flux raw material containing 13 to 22% of particles with a diameter of 105 to 149 μm is coated on the outer periphery of a core wire. In addition, the particles of 105 to 149μ described above and below are JISZ
What passes through the 100 mesh of the 8801 standard sieve, what remains above the 145 mesh, and what remains below 60 μm is measured by a light transmission particle size measurement method.

Next, the basis for determining the grain size range of the welding rod of the present invention will be described in detail.

The content of particles of 105 to 149μ in an amount of 13 to 22% is because if the content of particles of 105 to 149μ is less than 13%, it is not effective in improving dry cracking of the coating material. Reverse K. 22%
This is because if the content exceeds 100%, it will not be possible to improve the resistance of the coating material to fall off during transport of the welding rod.

The content of particles of 10 to 20 microns in an amount of 13 to 22% is because if the content of particles of 10 to 20 microns is less than 13%, it is not effective in improving the shedding resistance of the coating material. On the other hand, if it exceeds 22%, dry cracking of the coating material will occur frequently, and no improvement in preventing cracking will be achieved.

In this way, 13 to 22% of KlO5 to 149μ particles were added.
Containing 13 to 22 (Ft) of particles of 10 to 20μ prevents dry cracking. This is extremely important for improving your surname's resistance to shedding. or. The particle size of 30 to 60μ was reduced to 10 (fl). Particles of 30 to 60 μm are not in the particle size range that is effective in preventing dry cracking and improving the shedding resistance of the coating material. The above drawbacks have not been improved. Also, considering the amount of other particles necessarily included. Said 105~149μ
particles of 13-22%. 13-2 particles of 10-20μ
This is because in order to contain .2(:F6), it is preferable to keep the particles of .30 to 60 microns under 10 fl.

These optimum particle size ranges are extremely coarse. Coarse. A preferred method is to combine raw materials with different particle sizes, such as fine and ultra-fine.

The present invention will be explained in detail based on the following embodiments, but the embodiments in claim 2 and the following are merely examples. This is not intended to limit the invention. It goes without saying that any aspect of the subject matter of the present invention does not depart from the technical scope of the present invention.

Examples Lime having the particle size structure shown in Table 1. Fluorite, rutile,
Fe-Mn. Fe-Si. Prepare Maya. Using the ingredients shown in Table 2. Seven types (A to G) of substitute hydrogen-based flux raw materials were made.

The particle size distribution of the flux raw materials A to G is shown in Table 3. Figure 1 depicts this. Water glass is added to these flux raw materials. After kneading, it is applied to a mild steel core wire. A test bar was prepared by baking under normal drying conditions. Size of mild steel core wire: 40φ x 400mm Coating diameter of test rod: 6.25φ Dry cracking of welding rod. Drying crack occurrence rod (K9) Drying crack occurrence rate = x 100 Comparison based on total dry weight (Kg). The amount of dropout was 5k9, packed with test rods in a paper box. Dropped from a height of 1m onto a concrete floor. The weight (g) of the peeled coating was compared.

FIG. 2 is a diagram showing the dry crack occurrence rate ((L)) in the test results.

This diagram clearly shows the passage. Inventive products C, G, and F had a cracking incidence of O. In addition, particles of 10 to 20 μm were added to 13.1 (
:fl) No drying cracks occurred in B containing B. The fact that drying cracking did not occur even though A was outside the range of the present invention indicates that even if the particle size of 10 to 20 μm is less than the range of the present invention, drying cracking is not significantly affected. (However, the drop resistance deteriorates.) However, within the range of the present invention, the
D and E containing particles of 20μ (E also contains fewer particles of 105 to 149μ) are each 5 (610% before and after F6)
The incidence of cracking before and after. FIG. 3 is a diagram showing the results of a coating shedding test.

This is also clear from the diagram. Products C, G, and F of the present invention had a small amount of falling off. Also, D containing 13.5% of particles with a size of 105 to 149μ was small. The fact that the amount of particles falling off was small even though E was outside the range of the present invention indicates that even if particles of 105 to 149 μm are smaller than the range of the present invention, the amount of particles falling off is not affected. (Call drying cracks occur frequently.)However, within the scope of the present invention, A, B containing particles of 105 to 149μ (
A has a small content of particles of 10 to 20 μm) is 2, respectively.
610g above 0g? There is a lot of shedding on top! ). A drop-resistant surname is not good. As is clear from the results above, since A and B contain particles of 105 to 149 μm on the surface of the present invention, they are inferior in shedding resistance. D and E contain particles of 10 to 20 μm on the surface of the present invention, so drying cracks are likely to occur. It can be seen that the welding rod of the present invention must be used to satisfy both the requirements of preventing dry cracking.

Furthermore, when manufacturing the welding rod of the present invention, there is no need for strict temperature control as in the past. It can prevent dry cracking and improve resistance to falling off. In addition to reducing labor at the manufacturing site, it also reduces pittance. Defects such as blowholes are less likely to occur. A welding rod with good workability can be obtained.

[Brief explanation of drawings]

Figure 1 is a diagram showing the particle size distribution of low hydrogen-based coated arc welding rod coating materials (A to G). Figure 2 is a diagram showing the drying crack measurement results for coating materials A to G. FIG. 3 is a diagram showing the results of a shedding test for coating materials A to G.

Claims (1)

[Claims] 1. 13-22% particles of 10-20μ, 30-60μ
particles of 10% or less, particles of 105 to 149μ to 13 to
A coated arc welding rod characterized in that a coating material obtained by adding a fixing agent to a welding flux raw material containing 22% is applied to the outer periphery of a core wire. 2. The coated arc welding rod according to claim 1, wherein the coating material is low hydrogen-based.