JPS63199093A - Arc welding electrode coated on stainless core wire - Google Patents

Abstract

PURPOSE:To obviate uneven melting of a protective cylinder by using a flux which contains 3 kinds; CaF2, Al2O3 and CaO, consists of the balance inevitable impurities and is subjected to a melting treatment as a part of the raw materials for a coating material. CONSTITUTION:The coating material contains, by the total weight of the coating material, 1-12% flux which contains the three kinds; CaF2, Al2O3 and CaO, consists of the balance inevitable impurities and is subjected to the melting treatment. The coating material further contains 15-55% titanium compd. in terms of TiO2, 10-30% metal carbonate, 5-15% in total 1 or >=2 kinds of silica sand and silicate compd. in terms of SiO2, 3-15% metal fluoride, and <=25% metal powder. Such coating material is coated on a stainless steel core wire to form a coated stainless steel electrode. Satisfactory welding is thereby executed in a vertical position without generating the uneven melting of the protective cylinder.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a stainless steel coated arc welding rod, and more particularly to a stainless steel coated arc welding rod that has excellent vertical welding workability.

(Conventional technology) Conventionally, lime-fluorite welding has been used for stainless steel welding, which combines the advantages of lime type, which has excellent vertical and upward weldability, and titania type, which has excellent downward weldability. Lime titania stainless steel coated arc welding rods with rutile as the main coating material are widely used.

However, when performing vertical welding with lime titania type, the molten metal is on the lower side, so the lower side of the protective tube melts faster, resulting in a so-called one-sided melting of the protective tube, which is shaped like a fingernail. This causes problems such as impairing uniform arc directivity and lowering welding workability, as well as causing defects such as undercuffs (undercuffs) and poor fusion.

Therefore, until now, Japanese Patent Application Laid-open No. 54-122647,
As disclosed in JP-A No. 57-130797, improvements have been made by adding silica sand or silicate compounds to the coating to impart fire resistance to the coating.
The effect was not sufficient.

(Problems to be Solved by the Invention) The present invention has been made to solve the above-mentioned problems, and its purpose is to solve the problems described above.

An object of the present invention is to provide a stainless steel coated arc welding rod that has excellent vertical welding workability by using a melted flux containing CaO and the remainder consisting of unavoidable impurities as part of the coating material raw material.

(Means for solving the problem) As mentioned above, during vertical welding, single welding of the protective tube occurs, impairing uniform arc directionality and reducing welding workability, as well as undercutting and poor fusion. Since these defects also occur, various measures to improve them were considered.

As a result, by incorporating an appropriate amount of melt-treated flux containing CaFz+ u, o, and CBQ with the remainder consisting of unavoidable impurities into the coating material, the protective tube can be perfectly formed and maintained even during vertical welding. The present invention was developed based on the knowledge that the slag melts uniformly without unilateral melting, and that the fluidity of the slag is improved, resulting in a smooth bead shape. Based on the total weight, it contains 1 to 12% of a melt-treated flux containing three types of CaFz+u, Q, and CaO, with the remainder being unavoidable impurities, and further contains 15 to 55% of a titanium compound converted to TiO2, 10 to 30% of metal carbonate, one or more of silica sand and silicate compounds, StO,
A stainless steel coated arc welding rod characterized in that a stainless steel core wire is coated with a coating agent containing a total of 5 to 15% in terms of metal fluoride, 3 to 15% of metal fluoride, and 25% or less of metal powder. be.

(for production) The present invention will be explained in detail below along with its operation.

The major feature of the present invention is that CaF*s 7V,o,,C
The phenomenon of one-sided melting of the protective cylinder is improved by using a melt-treated flux containing three types of aO and the remainder consisting of unavoidable impurities as part of the coating material raw material.

In other words, to prevent partial melting of the protective tube during welding, Tl
0t+ ZrOx+ PJ,o,, Ca(L MgO
It is necessary to incorporate oxides with high melting points such as oxides into the coating material to improve the fire resistance of the coating. However, although TiO□CaO is used as a titanium compound and lime, which are the main components of the coating, no effect has been observed in preventing single dissolution, and oxides such as ZrOx+ Ajg03+ MgO are used as zirconium oxide. When raw materials such as aluminum oxide, alumina, and magnesium oxide are mixed into the coating material, no significant effect is observed in preventing single melting, and when excessively blended, arc instability, deterioration of slag removability, increase in spatter, etc. may occur, and welding Deterioration in workability becomes significant.

For the above reasons, as a result of various studies, A7. O.

When a melt-treated flux containing CaO is used, it is highly effective in maintaining the formation of a protective cylinder, and is effective in preventing the phenomenon of single melting. Furthermore, by adding CaFz, NtO
It was found that s+ CaO was effective in uniformly melting the protective cylinder with increased fire resistance and preventing single melting, and also improved the fluidity of the slag.

Therefore, it is possible to prevent partial melting of the protective cylinder by blending a melt-treated flux that contains three types of CaFg, 7VzOa + CaO, and the remainder is unavoidable impurities, but if it is less than 1%, it is not effective. No, 12%
If it exceeds this, the protective tube will become too long, the arc will become unstable, and breakage will occur, so limit it to 1 to 12%.

The purpose of adding rtog is to stabilize the arc, improve envelopment and release properties, and improve bead appearance and shape.If it is less than 15%, it is ineffective, and if it exceeds 55%, it will not be able to stand upright. Welding becomes difficult and the slag becomes hard.
It is limited to 15 to 55% since it may actually impair releasability.

Note that Ti01 here refers to T such as rutile, white titanium, titanium slag, illuminite, potassium titanate, etc.
Refers to the i compound converted to TiO□.

The combination of metal carbonates imparts high basicity to the slag, suppresses the increase in P, S, and Si in the molten metal, and effectively shields the arc from the atmosphere by creating a reducing atmosphere of CO□ gas produced by decomposition. to prevent blowholes from occurring. In addition, it is effective in stabilizing the arc in terms of welding workability, but it is not effective if it is less than 10% (and if it exceeds 30%, the peelability and fluidity of the slag will deteriorate, so it should be reduced to 10 to 30%.
limited to.

Note that the metal carbonate mentioned here refers to calcium carbonate, magnesium carbonate, barium carbonate, manganese carbonate, strontium carbonate, and the like.

The composition of 5lOt is 5% to improve the fluidity of the slag.
Although the above amount is necessary, if it exceeds 15%, the slag exfoliation property will be deteriorated, so it is limited to 5 to 15%.

Note that Sing here refers to silica sand, wollastonite,
Refers to silicate compounds such as potassium feldspar, mica, talc, kaolin, potassium silicate, sodium silicate, and lithium silicate converted into Sing.

The purpose of adding metal fluoride is to improve the fluidity of the slag and improve the bead shape, but if it is less than 3%, it is ineffective, and if it exceeds 15%, it will worsen the slag's exfoliability and cause arcing. Limit it to 3 to 15% as it will make it unstable. The metal fluoride mentioned here refers to fluorite, cryolite, magnesium fluoride, aluminum fluoride, barium fluoride, lithium fluoride, sodium fluoride, etc., and does not include CaF2 in the melted flux. do not have.

If the desired composition of the weld metal component is not satisfied depending on the chemical composition of the stainless steel core wire used, the metal powder may be Fe-Mo, Mo+ Fe-Nb, Nb, F.
e-Cr.

Cr+Nt, Mn, etc. are blended as alloying agents to improve the mechanical properties and corrosion resistance of the weld metal.

Others as necessary: Pe-Al, Fe-3t,
Fe-Ti, AZ+'L Ti, etc. can also be used as a deoxidizing agent.

Cr, Ni, Mn, St, Mo+ Cu+ N
When most of b is contained in the core wire, the alloying agent and deoxidizing agent to supplement the components consumed during welding are mixed according to the chemical composition of the stainless steel core wire to be used, so the minimum Although the amount cannot be limited, at most 25% is sufficient considering the transfer rate of each component from the coating material to the deposited metal, so the total amount of one or more of the metal powders is set to 25% or less.

The above is an explanation of the coating material components. Next, the stainless steel core wire in the present invention will be described. The weld metal conforms to JIS Z
In addition to those that have a composition that allows obtaining the Cr-Ni and Cr stainless steel components specified in 3221, it also includes those that have a composition that takes into consideration high strength, corrosion resistance, heat resistance, etc. The core component is Cr10
~28%, Mn 4.5% or less, St 1.5% or less, and further contains Ni 22% or less, and if necessary, Mo 4% or less, Cu 2.5% or less,
Nb 1.5% or less, Ti 1.0% or less, ■1.0%
The following examples contain 0.5% or less of N00.

In addition to the above-mentioned components, the coating material of the welding rod of the present invention also contains K,
0. Even if NazO or the like is blended within a range in which the total of each component does not exceed 10%, the properties of the welding rod of the present invention will not be impaired.

Here, referring to an example of the method for manufacturing the welding rod of the present invention, for example, a stainless steel core wire and a coating powder are prepared, and the coating powder and water glass (potassium silicate aqueous solution, potassium silicate aqueous solution + sodium silicate aqueous solution) are prepared. It can be produced by mixing with a suitable binder such as, coating the core wire, drying and firing at 200 to 450° C. for about 1 hour.

(Example) Table 1 shows the chemical composition of the stainless steel core wire.

The core wire dimensions are 4.0 mm in diameter and 350 mm in length.

Table 2 shows the compositions of welding rods based on these combinations of core wires and coating materials. The coating diameter is 6.5 am and the coverage is 34%. Table 3 shows the chemical composition of the stainless steel sheet.

Table 4 shows the welding workability test results for the combinations of the welding rods in Table 2 and the stainless steel plates in Table 3.

The welding position is vertical, and the groove angle is 70° with a plate thickness of 12n.
A welding current of 110 A (alternating current) was applied to a ■-shaped groove machined to a height of 8 mm.

From the above, welding rod symbol 11m1 of the example of the present invention. 2. 5゜7.9, 11, 14, 15.1? , 19.21°23.
25. In vertical welding, 27 and 30 do not suffer from single melting of the protective tube, uniform arc directionality is maintained, slag fluidity is good, bead shape is smooth, and spatter is not generated. It is clear that other welding workability such as slag release property is also good.

On the other hand, welding rods with symbols N13 and 24 of comparative examples have melted flux exceeding 12%, and NCL4 has a total Si0g conversion value of less than 5%, and N116°2
6 and 28 have a total TiO□ equivalent value of less than 15%, N18 and 29 have a total Si0g equivalent value of more than 15%, and N111O and 22 have a melted flux of less than 1% and are hidden. 12 means that the total number of metal carbonates is 10
%, N1113 and 29 have a total metal fluoride content of more than 15%, and N1116 has a total metal fluoride content of more than 3%.
%, and Arashi 18 has a total TiO□ conversion value of 55%.
Since the total metal carbonate content of Na2O and 28 exceeds 30%, both have poor welding workability as seen in Table 4.

Footnote 1) CaFz; 60%-/'JzOz;
20%-CaO; 19% melt-treated flux was used for welding. 1. 2. 3. 4. 5
．． 6°7.8, 9.10, 11, 12.13 and 14
It was used for.

CaFt; 40%-AhOs; 34%-CaO; 2
Welding rod symbol: 5% melt-treated flux,
15, 16, 17.1B.

Used on 19.20.21 and 22.

CaPz; 30%-uzo3; 52%-CaO;
A melt-treated flux consisting of 17% was applied to welding rods with symbols 难, 23, 24.25, 26゜27.28.29 and 30.
It was used for.

2) Rutile (TiOz; 96%) welding rod symbol: 1. 2. 3. 4. 5. 6. 7. 8
．． 9゜10.11,12,13,14,15.16゜1? , 18, 19. 20. 21, 22, 23° 24.2
5, 26, 27, 28, 29 and 30.

Welding white titanium (TiOg 598%) with rod symbol 1
It was used for 1 m1, 2.7, 8, 15, 16°19 and 20.

Potassium titanate (TiOz; 71%) was used for welding rod symbols 5.6.11, 12, 13.14°23 and 24.

Illuminite CTi0z; 39%) welding rod symbol 1
1h5, 6, 13, 14.15, 16°17 and 18.

3) Calcium carbonate (CaCO3; 99%) welding rod symbol magnetic 1.2, 3.4, 7, 8, 9° 10.11, 12
．． 15.16.17°1B, 19,20,21.22.
23° 24.27, 28.29 and 30.

Magnesium carbonate (MgCOz; 96%) was used for welding rods 5, 6.13, 14.25 and 2G.

Barium carbonate (BaCOa) welding rod symbol fish 5゜6.1
3.14.25 and 26.

Manganese carbonate (MnCO3; 98%) was used for welding rod symbols 27, 28, 29 and 30.

4) Weld silica sand (SiO□; 97%) with a welding rod symbol: 1°2.
3.4,5,6.11.12.13゜14.15.16
．． 19, 20.23°, 24.27 and 28.

Welding potash feldspar (SiO□; 64%) with the symbol NQ7,8
．． 17 and 1B.

Welding mica (Sin, H47%) with welding rod symbols 9 and 1
Used for 0.

Welding wollastonite (SiO□; 52%) with welding rod symbol pigeon 21 and 2
Used for 2.

Talc (St (h: 25%)) was used for welding rod symbols 25 and 26.

Kaolin (SxOz; 81%) welding rod symbol N11L
It was used in 29 and 30.

Potassium silicate (Sings 65%) welding rod symbol 1
,2,3.4,5,6,7,8,9゜10.11.12
,13.14.15°16.1? , 18.19.20.
21゜22.23.24.25,26,27゜28.2
9 and 30.

Sodium silicate (SiO□; 70%) welding rod symbol 11m5
．． 6. 11. 12. 13. 14°19.20
．． 23, 24, 25 and 26.

5) Fluorite (Cadi; 98%) welding rod symbol 11k
L1゜2.3.4.7.8.9,10.11゜12.1
5, 16, 19, 20, 27, 28, 29 and 30.

Welding cryolite (NasNFb: 97%) with symbol Na
5 and 6.

Magnesium fluoride (MgFz; 98%) was used for welding rod symbols 11h13 and 14.

Aluminum fluoride (7Vh i 100%) was used for welding rod symbols 111I117.18.21 and 22.

Barium fluoride (BaFz: 100%) was used for welding rod symbols 23, 24, 25 and 26.

(Effects of the Invention) As explained above, the welding rod of the present invention has excellent welding workability, and can perform good welding without causing partial melting of the protective tube, especially in the vertical position.

Claims (1)

[Claims] Based on the total weight of the coating material, CaF_2, Al_2O_3
, contains 1 to 12% of a melted flux containing three types of CaO and the remainder consisting of unavoidable impurities, and further contains Ti.
Titanium compound 15-55% in terms of O_2, metal carbonate 10-30%, one or more of silica sand and silicate compounds in total 5-15% in terms of SiO_2, metal fluoride 3-30% 1. A stainless steel coated arc welding rod, characterized in that a stainless steel core wire is coated with a coating agent containing 15% or less of metal powder and 25% or less of metal powder.