JPS6057955B2 - coated arc welding rod - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coated arc welding rod, and more particularly to a novel coated arc welding rod that is constructed with relatively low material cost and can exhibit excellent performance.

One of the essential components added to the coating material for coated arc welding rods is TiO.

It has many functions as a slag forming agent, slag viscosity regulator, arc stabilizer, etc., and ensures welding workability, beautiful heat, and prevention of joint defects such as undercuts. It plays an extremely important role.
Rutile and illuminite are currently known sources of titania.

Among these, the TiO2 content in rutile is extremely high,
Illuminite is several steps inferior to rutile in TiO2 content, and although it can be used as an auxiliary raw material for rutile, it is insufficient as a substitute for rutile. Therefore, rutile is currently used as a coating material for coated arc welding rods such as TiO.
It is considered indispensable as a second raw material. However, despite recent remarkable advances in welding technology, the demand for coated arc welding rods remains the highest among all welding materials, and the consumption of rutile is still on the rise. However, rutile is now in a state of depletion, and its acquisition is becoming more difficult every year. TiO can be substituted for rutile according to the following. There is a strong desire to develop material sources. The present inventors have focused on the above-mentioned circumstances and have been developing TiO as a substitute for rutile.

We have been conducting various research to develop new materials. As a result, Ti
0. If a high titania mineral containing 75 to 93.5% by weight, such as leucoxin, is adjusted to an appropriate particle size and incorporated into the coating material in an appropriate amount, it will be as good as a rutile-containing coated arc welding rod. Knowing that the performance could be ensured, the present invention was finally completed. That is, the coated arc welding rod according to the present invention uses a high titania mineral having a particle size structure containing 75 to 93.5% by weight of TiO2 as a TIO source and 80 to 95% by weight of particles with a particle size of 250 to 105μ. from 10 to M% by weight in the total coating material.
The first feature is that the content of illuminite and TiO2 as a TiO2 source is 75 to 93.
5% by weight and a particle size of 250 to 105μ.
Contains a high titania mineral with a particle size structure containing ~9% filtration,
The second feature is that the total coating material contains 10 to 44% by weight of illuminite and 5 to 44% by weight of high titania mineral.

The resulting coated arc welding rod exhibits better arc stability than commercially available welding rods, has a spray-like droplet transfer state, and has excellent compatibility with the base metal.

Furthermore, the high titania minerals referred to in this specification are minerals such as lyucoccin, which have not been used as raw materials for coating materials for welding rods, and can be obtained much more cheaply than rutile, making it possible to make the welding rods cheaper. Now we can provide it. By the way, the high titania mineral used in the present invention refers to one having a TlO2 content of 75 to 93.5% by weight. However, minerals with a TiO2 content of less than 75% by weight cannot be expected to function as a rutile substitute like illuminite because the amount of TiO2 is too small, while minerals with a TiO2 content of more than 93.5% by weight can no longer be Since they belong to the rutile family and are expensive, none of them meet the purpose of the present invention. In addition, when using this high titania mineral, the content of particles with a particle size of 250 to 105μ is 80 to 95% by weight.
The particle size must be adjusted so that The reason for this will be explained in detail in the examples below, but when the grain size structure becomes coarse, the arc becomes more intense and the compatibility with the base metal deteriorates, resulting in poor welding workability and joint performance, while on the other hand, when the grain size becomes too fine, This is because the arc force becomes weaker and the spread of the crater becomes smaller, resulting in a decrease in welding workability. Table 1 shows an example of the chemical components of rutile, illuminite, and leucoccin, which is a representative example of the high titania mineral referred to in the present invention.

Next is the blending ratio of the high titania mineral that satisfies both the TlO2 content and particle size structure, which must be set in the range of 10 to 54% by weight based on the total coating material.

However, if the blending ratio of high titania minerals is too low, the stability of the arc, the droplet transfer state, the spread of the crater will deteriorate, and the compatibility with the base material will become poor, making it impossible to achieve the original purpose. If the amount exceeds 54% by weight, the fluidity of the slag becomes excessive, making the slag bath extremely unstable, and the peelability of the slag deteriorates significantly. This place. In addition to high titania minerals, carbonate minerals are also included in the coating.
It is desirable to contain 9% to 3% of saliva and potassium feldspar. The reason for this is that, whether there is too much or too little carbonate mineral, arc strength, arc stability, droplet transfer conditions, crater spread, and compatibility with the base metal generally tend to deteriorate. Moreover, if the potassium feldspar is out of the above-mentioned preferred range, all of the above-mentioned performances will be extremely degraded. Next, when illuminite is included as a TiO2 source in addition to the above-mentioned high titania mineral, the blending ratio of the high titania mineral can be set to 5 to 44% by weight.

That is, if illuminite is contained in the coating material, it will serve as an auxiliary material for TiO2 and the total content of TiO2 will increase, so the blending ratio of high titania minerals should be kept to a slightly lower level. In this case, the coating must contain 10 to 35% by weight of illuminite in addition to the high titania mineral. The reason for this is that if the amount of illuminite is less than 1%, the arc force becomes weak and stability decreases, and the fluidity of the slag becomes excessive due to the droplet transfer state, the spread of craters, and poor compatibility with the base material. This is because there is a tendency to
In addition, it is desirable to contain carbonate minerals (limestone, dolomite, etc.) by 5 to 2%, and the content of carbonate minerals is 5% to 2%.
If the amount is less than 2% by weight or more than 2% by weight, all performances such as arc strength, arc stability, droplet transfer state, and crater spread tend to deteriorate. The present invention is generally constructed as described above, but the key point is that the first step is to blend a predetermined amount of high titania mineral having a TlO2 content within a predetermined range and whose particle size is adjusted to a predetermined particle size composition into a coating material. The second feature is that the high titania mineral and illuminite are each blended in predetermined amounts in the coating material, and in particular, by using lyucoccine, etc., which can be obtained relatively cheaply as a substitute mineral for rutile. As a result, an inexpensive and high-performance coated arc welding rod can be obtained.

Therefore, the present invention is characterized in that rutile is not used in principle, but since rutile itself does not pose any problem in terms of performance, the concomitant use of a small amount of rutile is not positively excluded. In addition to the above-mentioned components, the present invention uses silica sand, silicates such as mica and talc, oxides such as iron sand, manganese dioxide and alumina, fluorides such as fluorite and cryolite, Fe-Si. ．． Component regulators such as Fe-Mn, iron powder, starch, organic substances such as sodium alginate, and caking agents such as water glass are added in appropriate amounts as necessary, but the TlO2 content and particle size of high titania minerals All of them fall within the scope of the technology of the present invention as long as the composition and blending ratio in the coating material meet the above requirements. Next, the present invention will be explained with reference to experimental examples, but the following is not intended to limit the present invention, and it is of course possible to implement the present invention with appropriate modifications in accordance with the spirit of the preceding and following. You should see it.

Experimental Example 1 Experimental results will be shown in which an illuminite system is selected as an example of a coating system in which illuminite, iron sand, iron ore, etc. are blended, and leucoccin is used as a high titania mineral.

The chemical components of the ryukoccin used are shown in Table 2, the particle size composition is shown in Table 3, the basic formulation of the test reversal agent is shown in Table 4, and the sub-composition α that constitutes a part of the basic formulation is shown in Table 5. .

First, the basic formulation M shown in Table 4 was selected, and a coating material obtained by blending ryukoccin (Tables 2 and 3) in the ratio shown in Table 6 was coated with a coating material having a diameter of 4.0 WR and a length of 40077177 mm.
! Coat the coating material to a thickness of 6.25 to the mild steel core wire.

Using the obtained test welding rod, welding current 145 to 170
Workability was observed when welding was performed in A (A-C) and in all positions. The welding workability was evaluated based on the following items.

(1) Arc strength: The stronger the better (2) Arc stability: The more stable the better (3) Droplet transfer state
: Spray form is better (4) Crater spread:
The larger the size, the better (5) Compatibility with the base material: The easier it is to fit in, the better (6) Obstruction of the slag: It is better not to rub it in. (7) Peelability of the slag: The easier it is to peel, the better the results are shown in Table 7 Shown below.

As is clear from the results in Table 7, excellent welding workability cannot be obtained if the blending ratio of ryukoccin is too low or too high, but when the blending ratio is in the range of 5 to 4%, In either case, welding workability superior to commercially available products can be obtained.

Next, for those other than the basic formulation M in Table 4, a coating material with the basic formulation/Ryucoccin set at 7% by weight/30% by weight was prepared, and each test welding rod obtained in the same manner as above was welded. Workability was observed.

The results are shown in Table 8. As is clear from the results in Table 8, even when the ryukoccin content is within the preferred range (3% in this example), both the illuminite and limestone content are within the preferred range. Without it, it is difficult to obtain excellent welding workability.

However, test rod numbers 13 and 14, which satisfy all of these requirements,
Nos. 15, 18, 19, 22, 23, and 24 have welding workability that exceeds that of commercially available products. Next, in order to confirm the influence of the particle size composition of Ryukokushin on welding workability,
Prepare ryukoccin with the three particle size configurations shown in Table 9, and adjust the blending ratio of ryukoccin to 7% by weight and 42% by weight (both within the specified range of the present invention) using the basic formulation M shown in Table 4. The welding workability of each was observed in the same manner as above.

Note: Items within the scope of the present invention (same as Table 2) Items that are coarser than the scope of the present invention H: Items that are finer than the scope of the present invention The results are shown in No. 1.

Commercial product: Same as before ◎, 0, Δ, ×: As is clear from the results of the first cough from the same day, even if the blending ratio of ryukoccin is within the range specified by the present invention, the particle size structure of ryucoccin is not specified. If it is outside the range (sample rod numbers 2-0, 2-c, 5-ro, 5-c), satisfactory welding workability cannot be obtained.

However, when using Ryukoxin whose particle size structure is within the specified range (test rod numbers 2-I and 5-I), it is possible to obtain better welding workability than commercially available products. Experimental Example 2 Experimental results are shown in which lime and titania are selected as an example of a coating system in which illuminite, iron sand, iron ore, etc. are not blended, and leucoccin is used as the high titania mineral.

The ryukoccin used was the same as in Experimental Example 1.

The basic formulation of the sample coating material is shown in Table 11, and the sub-mixture β forming a part of the basic formulation is shown in Table 1. The basic composition N'' shown in Table 11 was selected, and the coating material obtained by blending Ryucoccin (Tables 1 and 2) in the ratio shown in Part 1 was applied to a mild steel of 4.0wn in diameter and 400wt in length. Apply the coating so that the coating diameter is 6.30 mm on the core wire.

Using the obtained test welding rod, welding current 150-180A
(A-C) and when welding in all positions, the workability was observed. The procedure for determining welding workability is the same as in Experimental Example 1.

The results are shown in Table 14.

Commercially available product: Lime titania coated arc welding rod ◎, 0,
Δ, Within this range, welding workability superior to commercially available products can be obtained in any case.

Next, for those other than the basic formulation N'' in Table 11, a coating material was prepared with the basic formulation/ryukoccin set at 7% by weight/23% by weight, and each test welding rod was obtained in the same manner as above. Welding workability was observed.The results are shown in the first bale.As is clear from the results of the first bale, even when the blending ratio of ryukoccin is within the preferred range (in this example, 2%), Unless both the content percentages of limestone and potassium feldspar are within the preferred range, it is difficult to obtain excellent welding workability.

However, test rod numbers 43, 44, which satisfy all of these requirements,
No. 45, 48, 49, 52, 53, and 54 provide welding workability superior to commercially available products. Next, in order to confirm the influence of the particle size composition of Lieucoccin on the welding workability for lime-titania-based products, we prepared Lieucoccin with the particle size composition shown in Table 9 as in Experimental Example 1, and The welding workability was observed in the same manner as in Experimental Example 1 when the mixing ratio of ryukoccin was 1 heel weight % and 5 seed weight % (both within the specified range of the present invention) in the basic formulation N'' shown in the table.

The results are shown in the first bale.

Claims (1)

[Claims] 1. As a TiO_2 source, the content rate of TiO_2 is 75 to
93.5% by weight and 80-95% by weight is 2
Coated arc welding, characterized in that the coating material contains a high titania mineral having a grain size of 50 to 105μ, and the high titania mineral is contained in an amount of 10 to 54% by weight in the total coating material. rod. 2 Illuminite and TiO_2 as sources of TiO_2
The content of 2 is 75 to 93.5% by weight, and the 8
0 to 95% by weight consists of a particle size composition of 250 to 105μ High titania minerals are contained in the coating, 10 to 35% by weight of illuminite and 5 to 44% by weight of high titania minerals are contained in the coating. A coated arc welding rod characterized by containing: