JPS61206595A - Coated electrode - Google Patents

Abstract

PURPOSE:To improve the bindability and flexibility of a coating material and to improve rod burn resistance and the efficiency of a welding operation by incorporating a specific ratio of sepiolite having a specific grain size and weight ratio into the coating material for a non-low hydrogen type arc welding electrode and adjusting the ratio of the org. material contained therein. CONSTITUTION:The sepiolite having <=105mu grain size and >=85wt% ratio is incorporated at 0.5-5.0wt% into the coating material for the non-low hydrogen type coated electrode. The org. binder material prepd. by incorporating an alkaline soln. and protein, etc. into water glass is further incorporated at 0.3-3.5% therein. The fibrous crystal structure of the sepiolite increases the viscosity of the binder and improves remarkably the flexibility thereof. The heat radiation is made active by the dehydration of the water of crystallization of the sepiolite and the rod burn resistance is improved. The disadvantage in the welding workability of the non-low hydrogen type arc welding rod contg. hydrogen at a higher ratio is thus overcome and the efficiency of the welding operation is improved.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention improves the adhesion of the coating material to improve productivity, and improves the flexibility of the coating material and rod resistance when used at high currents. This relates to a non-low hydrogen coated arc welding rod (hereinafter referred to as a non-low hydrogen bar) that has significantly improved hardening properties. Compared to this, since there is more water Xit in the weld metal, the cracking resistance and impact toughness of welded objects, which are highly constrained, are inferior, but since welding workability is good, the range of use is extremely wide. For example, Illuminite welding rods for all positions are used in shipbuilding, bridges, machinery, architecture, pressure vessels, etc., and Lime Titanium welding rods are used for light steel frames, automobile parts, segments, drums, etc., and both are used for thin sheets of mild steel. , suitable for welding medium plates.

By the way, in order to improve the productivity of non-low hydrogen rods and the workability of bath work, it is reported in Japanese Patent Publication No. 59-2599 that the coating agent can be fixed by adding 0.1 to 3 layers of pectolite to the coating agent. It has been shown that it is possible to improve the coating properties and prevent the coating from falling off during transportation, improve the coating properties during manufacturing, reduce scratches and dents, and improve production yield.

However, since the reserves of hectorite are extremely limited, there are limits to its application.

Mayu, regarding the improvement of flexibility of coating materials, for example,
As described in Japanese Patent Application No. 4-24974, a mixed additive consisting of an alkaline solution, a tandrite, an aluminum salt, and a polysaccharide in an amount of 1 to 10% is added to water glass as a fixing agent. Kanashi has been improved. However, when non-low hydrogen rods using this adhesive are used at high currents, the organic matter in the coating material in the latter half of the welding rod decomposes and burns due to Joule heat, which tends to cause so-called stick burn phenomenon. There is a disadvantage that the arc becomes unstable when welding if a part that has been welded is used. Therefore, JP-A-57-206
No. 595 discloses 81 in water glass as a fixing agent.
Stick burn is prevented by using high molar ratio water glass with a molar ratio of 0□/Na2O of 2.8 to 3.8.

However, as described in JP-A-57-100896, increasing the molar ratio of water glass causes drying cracks during production, and when the molar ratio is high, Na
Since the amount of alkali oxides such as 20 and 20 is reduced, the arc condition deteriorates and the amount of spatter increases.

In this way, the current non-low-hydrogen rods have good productivity, the flexibility of the coating material, and the stick burn resistance when using high currents.
It was very difficult to improve welding performance and to satisfy other welding workability such as arc condition, spatter, slag condition, and bead appearance.

It has been strongly desired by various industries that use welding rods to obtain a welding rod that satisfies all of these requirements.

[Problem that the invention seeks to solve]

In view of the above-mentioned circumstances, the present invention carefully examines the composition of the coating material, ensures the conventional performance, and makes the adhesion of the coating material extremely good, thereby improving productivity. We have developed a non-low-hydrogen rod that has excellent coating flexibility, which is required when welding in narrow areas, and also has sufficient coating resistance even when using high Ti'r. This is what we provide.

[Means for solving problems]

The present invention has been developed as a result of various studies on coating materials for non-low hydrogen rods in order to meet the above-mentioned demands.The present invention has improved productivity and significantly improved the flexibility of the coating material during bath welding work and the resistance to rod burning. The gist of this is that 1.
0.5 to 5.0% of sepiolite containing 85% by weight or more of particles of 0.05μ or less (hereinafter expressed as a ratio), and 0.5 to 5.0% of organic matter.
Regarding improvement of productivity and flexibility of coating material for non-low hydrogen rods, which contain 8.5% and have a ratio of sepiolite to organic matter of t-0.3 to 3.5. has conducted various researches, finding that it is extremely effective to improve the adhesion of materials on the coating material and to improve the bonding force between the core wire of the welding rod and the coating material. As a result, it was found that the combined use of sepiolite and organic matter and limiting the ratio of the amount of sepiolite to the amount of organic matter are extremely important and highly effective. Sepiolite fl natural hydrated magnesium silicate, chemical structure ti(Of(2)4(O
f()4Mg 881120306~8 It is expressed as k120, has a fibrous crystal structure, and has good dispersibility in water glass. The complex intertwining of these molecules causes them to separate and increase the viscosity of the coating material. Furthermore, during the drying process during the production of welding rods, the biolite itself has the property of solidifying scales and other coating materials as well.

Therefore, since these have good thickening properties and solidifying properties, the coating material has excellent adhesion properties.

In addition, as mentioned above, sepiolite contains water of crystallization, so when welding using high current, the water of crystallization is dehydrated from the coating material on the latter half of the welding rod by the Joule heat of bath welding. The active heat dissipation from the coating material also improves the stick scorch resistance of the coating material.

As described above, sepiolite can greatly contribute to improving productivity, flexibility of coating materials, and resistance to stick burn when using high currents. When fc is applied, the arc force becomes weaker and becomes unstable), and more spatter is scattered. Therefore, it is necessary to limit the grain size and addition amount of sepiolite.Furthermore, in order to maintain a good arc condition and maintain sound welding workability, it is impossible to use organic substances in combination, and the ratio of the amount of sepiolite to the amount of organic substances is We confirmed that this is an important requirement. The present invention has been made based on the above findings. Note that the organic substances referred to here include starch, cellulose,
It refers to wood flour, dextrin, sodium alginate, etc., and can be used alone or in various combinations.

[Effect]

The effects of the present invention will be explained in detail below.

In the non-low hydrogen rod of the present invention, first, 105
Containing sepiolite with a particle size of 85 or more is to improve stability and usability of welding workability, improve adhesion and uniformity of the coating material, improve production yield, and improve coating material flexibility. Decorated to improve flexibility. Its particle size is 105
If the content of particles larger than μ is 15% or more, the arc becomes unstable and there is a lot of spatter, and in terms of productivity, the dispersibility of fibrous sepiolite deteriorates and the adhesion of the coating material deteriorates, which makes it difficult to manufacture welding rods. During the drying process, scratches, dents, and scratches are likely to occur on the surface of the coating.

The flexibility of the coating material is poor during t7j% contact.The coating material peels off, and if welded in this state, a coating tube will not be formed, resulting in insufficient shielding and unstable arc directionality, resulting in blowholes in the welded metal. This results in welding defects such as insufficient penetration, poor weld penetration, and deterioration of bead appearance.

Next, the addition of sepiolite was limited to 0.5 to 5.0% in order to fully utilize the effect of sepiolite without deteriorating other properties. The solidification properties of the coating material are as poor as before, resulting in lower production yields and deterioration of the flexibility of the coating material.Furthermore, when welding at high currents, the coating material in unused areas has poor stick scorch resistance. If you use it as is, the arc force will be weak and unstable, resulting in increased spatter scattering, and the deoxidizing agent in the coating will deteriorate, making it impossible to fully deoxidize the weld metal, which will cause blowholes and bits to occur. becomes. - If it exceeds 5,096i, the arc force will be weak and there will be a lot of spatter, and furthermore, the coating will become too dense and the surface of the coating will dry first in the drying process, and the moisture inside will be absorbed in the undried state. When this residual moisture evaporates due to the drying heat and the water vapor pressure inside the coating exceeds a limit value, the surface of the dried coating is broken and dry cracks occur.

The reason why organic matter is contained in the coating material in an amount of 0.5 to 8.5 is to ensure arc stability with appropriate arc force, obtain defect-free weld metal, and contribute to improving productivity. If it is less than 5%, the arc becomes unstable due to the weak arc force, and a lot of spatter is scattered, leading to insufficient weld penetration and slag entrainment, resulting in poor welding workability. When manufacturing fc welding rods, scratches, dents, and scratches are likely to occur on the surface of the coating material, resulting in a decrease in production yield. On the other hand, 8.5
If it exceeds 1i, even if other components are adjusted, the stick scorch resistance of the unused part of the coating will deteriorate when high electric current is used, and furthermore, if it is left in the atmosphere after manufacturing or re-drying. The rate of moisture absorption of the coating material increases, and if it comes into contact with TffI, diffusible hydrogen particles will increase in the weld metal, resulting in deterioration of cracking resistance, blowhole resistance, etc.

The ratio of sepiolite to the amount of organic matter is 0.3 to 3.5
The reason for this is to fully satisfy the requirements of flexibility, flexibility of the coating material, and stick burn resistance of the coating material at high currents, and to prevent deterioration of other properties as well. If the ratio is less than 0.3, the adhesion of the coating material decreases, making it impossible to achieve the above-mentioned object of the present invention, and in particular, the coating material has poor stick scorch resistance during bath welding, resulting in poor welding properties. This will result in deterioration of properties and welding defects.

Furthermore, if the ratio exceeds 3.5t, the number of cis/9 vines that make the arc unstable will increase, and the cybeads that are difficult to spread into the arc will take on a convex shape, further weakening the arc force and causing slag. The viscosity of the molten slag increases, making it easier for the molten slag to become entangled in the coating tube, resulting in insufficient molten penetration and slag entrainment.

〔Example〕

Below, based on Examples, the effects of the present invention will be specifically described by comparing the present invention 14J with a comparative example and a conventional train.

Table 1 shows the various particle sizes of sepiolite subjected to the test, and Table 2 shows the welding rods of the present invention, comparative welding rods, and conventional welding rods with each coating type of illuminite type, lime titania type, and iron powder iron oxide type. It shows the results of various performance tests of welding rods.

The test connecting rod was manufactured by adding a fixing agent to each of the coating materials shown in Table 2 and performing wet mixing to obtain a diameter of 4.0 m.
A soft steel core wire of
50■ After binding and coating with a normal extrusion coating machine, the maximum temperature is 15 for Illuminite and Lime Titania types.
Various welding rods were prepared by drying at 0°C and a maximum temperature of 190°C using iron powder and iron oxide.

Each test method and its acceptance criteria are as follows.

In the ninth coating shedding test to quantify the adhesion of the coating, a product weighing approximately 1.5 kg was prepared with a plate thickness of 6mm.
X300 ■X 40 in 1 minute in a 720m steel box
The coating was rotated at a rotating speed for 5 minutes and the rate at which the coating material fell off was measured, and those whose rate of shedding was 2 seconds or less were judged to be good. Regarding the production yield test, approximately 150 welding rods are manufactured, and those that do not have scratches, dents, scratches, or dry cracks during the painting and drying process are considered good, and the ratio of good welding rods to the total welding rods manufactured is calculated as the production yield. The value of Toshiro is 9
Those with a score of 9 or more were considered good. Regarding the flexibility test of the coating material, the welding rod is fixed to a part of the fixing jig 4 shown in Fig. 1 with a holder gripping width of 1t, and is bent into an arc shape toward the other end. Expressed in bar bending angle,
As shown in Fig. 1, the coating material of the welding rod 2 which is pressed and bent against the circular arc surface of the tubular jig 3 of 160+w+' is starting to chip, and when the welding rod is stopped, the extension line of the tip of the welding rod and the jig. It is indicated by the angle (θ) formed with the nine welding rods set first, and the seven angles are the average value of the 10 test welding rods, and those bent at 180° were considered good. Next, the coating material's stick scorch resistance was tested on a mild steel plate (thickness: 12 mm, width: 100 m, length: 800 wm).
) Perform downward bath welding using AC welding loss using ft,
The current is 200A for Illuminite type and Lime Titania type.
For the iron powder iron oxide type, the test is conducted at 180A, and the judgment method is that the coating agent in the unused part deteriorates and a coating tube is not formed, and the arc condition suddenly changes and becomes unstable and the arc force decreases. The arc was extinguished at the position where it began to arc, and the length of the remaining bath welding rod at that time was expressed as the average value of 10 test welding rods. Furthermore, as another bath welding workability test, Illuminite and Lime Titanium welding rods were tested in a downward, horizontal fillet position at 180A.
Standing position at 150A! All iron powder iron oxide welding rods were investigated at 160A in a downward and horizontal fillet position.

Regarding the determination method, arc state, st'? Items that were satisfactory in terms of the amount of ivy, slag condition, bead appearance, etc. in each bath contact position were evaluated as good.

Table 1: Grain size structure of sepiolite (grain size in Table 2: 1, A2.46~A11.A21~A26
is illuminite type, &3,44.412~A16
．． M27 to M31 indicate lime titania type M5. flat 1
7-420. A32 to M35 indicate iron powder iron oxide type. A
1 to 5 are rows of conventional welding rods, and although welding workability such as arcing, spatter, and slag conditions is good, the adhesion of the coating material is poor because sepiolite is not added, resulting in poor production yield and coating material. The flexibility and stick scorch resistance of the steel have deteriorated. A6 to 420 are related to the welding rods of the present invention.The particle size and addition amount of reseviolite are appropriate, and the ratio of the amount of sepiolite to the amount of organic matter and the amount of organic matter is also appropriate, so the adhesion of the coating material is good, showing 2% or less. As a result, the production yield has improved to over 99%, and the flexibility of the coating material has decreased to θ = 18 without any shedding of the coating material.
0', which is good. In addition, the stick burn resistance of the coating material also provides good bath ridge workability, including hardness, so it can satisfy all performance requirements. It was found that there is a significant effect on improving sexual performance.

Next, Ya21 to Ya35 are examples of comparative welding rods, and Mu21 and A31 have sepiolite particles of 105μ or less.
The adhesion of the coating material is improved because more than 5.0% of sepiolite is used in many cases, and the flexibility and stickiness resistance of the coating material is good, but if the amount of sepiolite added exceeds 5.01i As a result, the particle structure of the coating material becomes too dense, resulting in drying cracks and a decrease in production yield. In both cases, the amount of sepiolite was too high relative to the amount of organic matter, so the arc stability was poor, there was a lot of spatter and mother ivy, and the bead appearance was bad. In case of rot 22, the particle size structure and addition of sepiolite and the amount of organic matter are appropriate, but the amount of sepiolite relative to the organic material is too small, so the stick-grilling resistance is poor. 23 and 430 have a lot of organic storage, so they have poor stick scorch resistance.For 430, although there is a lot of sepiolite added, there are few particles of 105μ or less, so the adhesion of the coating is poor.Production yield and coating The flexibility of the agent deteriorates, and the arc condition also worsens. In A24 and A33, the amount of sepiolite and organic matter added and the ratio of the amount of sepiolite to the lid of organic matter are appropriate, so the stick burn resistance is good and the welding work, such as the arc condition and bead appearance, is also satisfactory. Since the number of particles with a particle size of 105μ or less is 85μ, sufficient hardness cannot be obtained, and the production yield and readability of the coating material are also deteriorated. In A25 and Mu32, although the particle size structure of sepiolite is appropriate, the purpose of the present invention cannot be achieved because the blended rice is small. M26. M28. In Column 34, the particle size structure of sepiolite is less than 105 μm, so the adhesion of the coating material deteriorates, making it impossible to meet the production yield and flexibility of the coating material. Due to the large amount of addition, the 61 arc was unstable and there was a lot of spatter, and because the arc did not spread, the bead became convex, and when multilayer welding was performed, slag entrainment and poor fusion occurred. However, in these three comparative examples, the water of crystallization in sepiolite is effectively utilized, so the resistance to stick burn at-
I can see that it is doing well. In A27 and Mu29, the particle size structure of sepiolite is within the range of the present invention, and the amount added is also small, so the adhesion of the coating material is poor, and during manufacturing, the coating material often suffers from scratches and scratches during the painting and drying process. This indicates that the production yield is poor and the flexibility of the coating material is also poor.

As described above, if the amount of sepiolite is less than 0.5%, burnout is likely to occur, but since the amount of organic matter is appropriate, the arc condition is good and the welding workability is fully satisfactory. l6
Regarding No. 35, the particle size structure and addition amount of sepiolite are appropriate, so the adhesion of the coating material is improved, and since the amount of organic matter is appropriate, the stick scorching resistance is also good, so the main objective of the present invention is achieved. If the ratio of sepiolite to organic material is too large, the arc will not be stable, resulting in increased spatter scattering and poor welding workability, such as deterioration of bead appearance.

〔Effect of the invention〕

As explained above, the welding rod of the present invention overcomes the drawbacks of conventional non-low hydrogen rods, improves the adhesion of the coating material, significantly improves productivity and flexibility of the coating material, and can be used at high currents. By providing welding rods that can greatly improve stick burn resistance, welding work is easier and can greatly contribute to improving the efficiency of bath welding work.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side view of a welding rod bending jig for explaining the flexibility test of a covered arc welding rod. 1... Gripping allowance for welding rod, 2... Welding rod, 3...
Tubular jig, 4...Fixing jig. Agent Teruo Taniyama '1'' Fig. 1 7: 3 @Je 4 Shino 4 Koku 2 Jaipe 2:38 杞樺, 3: III-shaped j♂ tool, ni 1. 2 WA Establishment 3 ♂ Applicant Procedural Amendment Form Showa Woman Hand R Month/Rho Date Name (Name) Examiner 1 Day Water V Price (X Chung Ho-Ak 4, Agent Address 2-6 Marunouchi, Chiyoda-ku, Tokyo) No. 2 Marunouchi to Shigesu Building 330 - ~ 7. Amendment subject to amendment We will amend the following ring in the specification of this application. Note 1, in the 1st line of page 3, the phrase "addition of 10 chlorides" has been replaced with "10 "Weight whisper addition" is corrected.

Claims (1)

[Claims] The coating material contains 0.5 to 5.0% by weight of sepiolite containing 85% by weight or more of particles of 105μ or less, and 0.5 to 8% by weight of organic matter.
．． A non-low hydrogen-based coated arc welding rod characterized by containing 5% by weight of sepiolite and having a ratio of sepiolite to organic matter of 0.3 to 3.5.