JPS61216891A - Coated electrode - Google Patents

Abstract

PURPOSE:To improve the equal leg characteristic of high electrode manipulation ratio weld beads with respect to a coated electrode for fillet welding by limiting the contents of TiO2 and Al2O3 and the total content of 1 or 2 kinds of FeO and Fe2O3 constituting a coating material. CONSTITUTION:The TiO2 to be incorporated into the coating material is limited to 1-4%, the Al2O3 to 1-5%, the total of 1 or 2 kinds of the FeO and Fe2O3 to 6-10% (respectively by weight %). SiO2 is determined at 15-30%, the total of 1 or 2 kinds of CaCO3 and MgCO3 at 2-6%, the total of 1 or >=2 kinds of CaO, MgO, MnO and MnO2 at 1-10% and Na2O and K2O at 1-5%. Fe is determined at 30-60%, Mn at 3-10% and org. material at 0.6-1.5%. The coated electrode for fillet welding having the excellent equal leg characteristic of the high electrode manipulation ratio weld beads is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application) The present invention relates to a coated arc welding rod for fillet welding, and particularly to a welding rod that is capable of high-speed welding and has excellent isopod properties.

(Prior technology) Conventionally, iron powder iron oxide coated arc welding rod (i!5D4327
), Iron powder low hydrogen coated arc welding rod (JI8 D 50
26) and special coated arc welding rods (JIB D 434
0, D 5000), etc., are used. In recent years, in order to promote high efficiency in fillet welding, an increasing number of welding sites have been increasing the unit welding rod length to the same bead length, that is, welding with a so-called high rod welding ratio.

However, with currently commercially available coated arc welding rods, when welding at a high rod ratio, the slag followability deteriorates.
It has been pointed out that defects such as undercuts occur, which leads to deterioration of the bead appearance and shape, and in particular, that the isopodality is significantly inferior. For this reason, as a coated arc welding rod with good isopodity at high rod ratios, for example,
As shown in Japanese Patent No. 7-134296, Z
ZrO2-A containing a large amount of rO□ and At20°
t20. - SiO□-based coated arc welding rods have been proposed. However, with this welding rod, the rod operation ratio is 1.
6 is the limit, and at rod ratios exceeding 1.6'4, the balance is poor and welding defects such as undercuts and bits occur, making it impossible to obtain a sound weld. .

In addition, as a method for improving equivalence, JP-A-56-7159
As shown in Publication No. 6, a coated arc welding rod in which the particle size structure and apparent density of iron powder are adjusted has been proposed. However, even with this welding rod, in high rod ratio welding of 1.7 or more, the equiambicality is poor and is limited to 1.4 at most. As described above, there is a strong demand for the development of a welding rod with good equiambicity in high-speed welding where the rod working ratio is 1.7 to 2.0 (hereinafter simply referred to as high rod working ratio welding).

(Problems to be Solved by the Invention) The present invention provides excellent ambidextrous properties such as horizontal fillet welding with a high rod ratio, without deterioration of the peak appearance or shape, and without the occurrence of welding defects such as undercuts or pits. The purpose is to provide a coated arc welding rod.

(Means for Solving the Problems) The present invention is a coated arc welding rod developed as a result of various studies in view of the above-mentioned actual situation, and its characteristics are particularly unique to TiO□′1. 1-4% by weight, At203'I
k: 1 to 5% by weight r FeO# The total amount of one or two types of Fe2O3 is limited to 6 to 10% by weight.

That is, TiO□ is one of the slag components most suitable for high rod ratio welding, and is commonly used in order to improve the followability of slag in high rod ratio welding. However, at the same time, the slag tends to drip, resulting in a concave bead, and has the effect of significantly deteriorating the properties. On the other hand, At2
03 has the effect of increasing the viscosity of the slag and improving the isotropic properties, but at high rod ratios, it has the contradictory effect of deteriorating the followability of the slag. On the other hand, FeOr Fl11203 stabilizes the slag flux and improves the slag followability in high rod ratio welding, but its effect is not sufficient when used alone. As mentioned above, T10□, ht2o, and FeO.

Fe12. Focusing on the effects of each of these, we conducted various combination experiments and found that welding with good performance, such as no deterioration of the peak appearance or shape, and no welding defects such as undercuts or bits, in horizontal fillet welding with a high rod ratio. We have found an appropriate range of ingredient amounts. The gist is the TIO□ mentioned above.
, At20. and FeO, F (S1 in addition to 1203
0□15-30wt-, CaC0,, 11 of MgCO3
! Or a total of 2 to 6% by weight of two types, CaO, MgO
r A total of 1 to 10% by weight of one or more of MnO+ and MnO□ *Na2O and K2O 1 to 5% by weight, Fe 30 to 60% by weight, Mn 3 to 10% by weight.

The present invention relates to a coated arc welding rod for horizontal fillet welding in which the periphery of a steel core wire is coated with a coating material containing 0.6 to 1.5% by weight of organic matter.

The details of the present invention will be described below. In this specification, q refers to % by weight.

SiO□ is a component that acts as a slag forming agent and has a large effect on the viscosity of the slag and the strength of the arc.If it is less than 15 inches, the viscosity of the slag is low and the strength of the arc is also weak. Therefore, in a high rod ratio range, the slag tends to come into contact with the tip of the protective cylinder, making the arc unstable, which adversely affects the bead shape and deteriorates the balance. On the other hand aos
1: If it exceeds 1, the viscosity of the slag will be too high, and at the same time, the strength of the arc will be very strong, and the arc will not spread, so undercuts will easily occur and the appearance of the peed will deteriorate. began to invite

TiO□ is a component that adjusts slag fluidity and slag peelability.
If it is less than 1'lA, the fluidity of the slag is insufficient, which tends to cause deterioration of the pead shape. However, if it exceeds 4%, the fluidity of the slag becomes excessive, and although it is suitable for high rod ratio welding, the slag tends to sag, the bead shape deteriorates, and the compatibility is particularly poor, so the upper limit is 4%. And so.

The carbon dioxide gas produced by CaC0, MgC0° arc heat exerts a shielding effect, but if the total amount of one or both of CaC0, MgCO3 is less than 2%, no shielding effect can be obtained. If the content exceeds 6%, the melting point of the slag decreases and the viscosity decreases, resulting in deterioration of the bead shape.

CaO, MgO, MnO, and MnO2 are effective in adjusting the slag melting point and viscosity, but if the total content of one or more of CaO, MgO, MnO, and MnO2 is less than 1%, the effect cannot be obtained; If it exceeds this, the melting point and viscosity of the slag will decrease! In the high rod ratio range, the pead shape deteriorates and welding defects such as undercuts and bits occur.

It is an effective ingredient for increasing the viscosity of the At20° slag and making the bead have a good isosceles shape. If it is less than 1 ts, the effect cannot be obtained. The other 5%! If it exceeds this, the viscosity of the slag becomes excessive and the bead shape deteriorates.

Na2O, K2O These are mainly added as a fixing agent, and they stabilize the arc and improve blowhole resistance, but if the total amount is less than 1%, the effect will not be achieved. On the other hand, if the total exceeds 596, the arc will not expand and the bead shape will become a convex bead, so the upper limit is set at 5.

F・0. F・203 Stabilizes the slag coverage and improves the followability of the slag in high rod ratio welding, making it evenly spaced.

However, the total of one or two types of F・O, F・203 is 6
If it is less than 10%, no effect will be obtained, and if it exceeds 10%, the melting point and viscosity of the slag will decrease, and the bead shape will deteriorate.

F. In the present invention, F. refers to the total Fe content of ferroalloys and iron powders blended in the form of iron powder, and should be kept at the lower limit of 30% 't' in order to maintain welding efficiency. On the other hand, 6
0! If At' is exceeded, the arc will not spread and the stick burn resistance will deteriorate, so the upper limit of 't' was set at 60%.

Mn In the present invention, Mn refers to metal Mn ("Fe-M
This refers to the total amount of Mn in the mixture, but if it is less than 3, deoxidation is insufficient and holes, bits and blowholes are likely to occur. On the other hand, if it exceeds 10%, deoxidation becomes excessive and mechanical properties such as toughness and ductility deteriorate, so 101? Let rJ=a.

Stability and spraying of organic material arc is effective for maintaining strength and restriking property, but below 0.6 inches,
I can't get that effect. On the other hand, if it exceeds 1.5%, the arc will be too strong, undercuts will easily occur, and the moisture absorption resistance will deteriorate and the amount of fume will increase, so the upper limit was set at 1.5%.

Since the coating material of the coated arc welding rod of the present invention is configured as described above, it is possible to obtain a coated arc welding rod that has a good equilateral column in high rod ratio welding and further improves work efficiency. Ta.

(Example) Next, the effects of the present invention will be illustrated in more detail with reference to Examples. Test welding rods with coating compositions shown in Table 1 were prepared and welded under the welding conditions shown below, and the workability of each was comprehensively evaluated using high rod ratio welding. The results are also listed in Table 1. The results were obtained.

In addition, the evaluation criterion fs in the table is shown below.

High rod ratio Good followability of slug O Poor followability of slag × Difference in leg length between upper and lower legs of isopodal column is 1.5 tm or less O Difference in leg length between upper and lower legs exceeds 1.5 m Undercut resistance, torsion resistance No undercuts occur O Undercuts occur X Bead appearance Good bead appearance Q Bead appearance is poor Rate is 10% or less ○ Rate of occurrence of plowholes is over io* × Bead shape Good bead shape O Bead shape is poor × Mechanical properties Mechanical performance is plate steel plate standard Gr, 3'Ik: Satisfied
O Mechanical performance does not meet double steel plate standard Gr, 3'g ×
Welding efficiency: The welding efficiency of the center wire is 110 seconds or more The welding efficiency of the O center wire is less than 110% Approximately 20μ of 14ts X 100”wX 1500sa+
'On the two flat plates? Form a Tffl corner weld test plate.

In Part 1, Todoroki l~20 are comparative examples, mu21~42
shows an example of the present invention.

Since the mulch lacks S10□, the viscosity of the slurry and the gas is low, and the strength of the arc spray is 5, weak. ,.

1) During high rod ratio welding, the slag drips and comes into contact with the tip of the protective tube, resulting in poor bead shape and bead appearance.

Grave 2 has an excessive 810 □, so the arc blowing strength is too strong, and the slag followability deteriorates due to high rod movement ratio welding, the bead appearance is bad, and there is an undercut. Occurred.

No. 43 had poor slag followability and deteriorated bead shape due to insufficient T10□.

I64 is a high rod ratio welding in which the fluidity of the slag is excessive due to excessive TiO2, and the slag followability is good, but the slag does not drip 9, and the bead shape is concave. However, the isosysmodal column has deteriorated significantly.

In J165, the total amount of CaCO5j MgCO3 was insufficient, so the shielding effect could not be obtained and pits were generated in the bead.6 In A6, the total amount of CaCO3 and MgCO3 was excessive, so the melting point and viscosity of the slag decreased. - The bead shape has deteriorated. Flat 7 has a lack of the sum of MgO, CaO, MnO and MnO2, so the melting point and viscosity of the slag are lower than p4'.
11. The effect of Jl cannot be obtained and the followability of the slag deteriorates.
The bead shape has deteriorated. Undercuts also occurred.

In A8, the sum of the three types of CaO, MgO, MnO, and MnO2 was excessive, so the melting point and viscosity of the slag were 9 below, and the bead shape was deteriorated. Undercuts and pits also occurred.

In case No. 9, the viscosity of the slag was low due to the lack of Al2O, and the isosceles pillars deteriorated.

In case of Rum 10, because AL20s is excessive, the isosceles column is good, but the viscosity of the slag is too high, the followability of the slag deteriorates, and there is underforce in the latter half of the bead.

A crash occurred. Also, the bead shape became convex.

All is due to the lack of NazO and K2O,
The bead shape was poor due to poor arc stability and poor slag followability. Moreover, the blowhole resistance effect was not obtained and the number of blowholes increased.

412 has excessive Na2O and K2O, which causes the arc to spread insufficiently, resulting in a convex bead shape. 413 has a lack of oxide of F, resulting in poor slag coverage. is not stable. In addition, the bead shape deteriorated because the slag followability deteriorated.

In No. 414, since FeO and F.203 were excessive, the melting point and viscosity of the slag decreased, the fluidity of the slag became excessive, the slag came into contact with the tip of the protective cylinder, and the bead shape deteriorated.

Since 1615 lacked Fe, the welding efficiency deteriorated, the bead was not thin, and the shape also deteriorated.

In the case of Rubber 16, the arc did not spread due to excessive F* content, and the stick burn resistance deteriorated and the bead shape in the latter half became a convex bead.

417 is deoxidized due to lack of Mn.
Pit and blowhole occurred.

l618 has an excess of Mn, resulting in excessive deoxidation,
0 A19, which did not have satisfactory mechanical properties such as toughness and ductility, lacked organic matter, so the arc blowing strength was weak and unstable, and the bead shape and appearance were poor.

In case of No. 20, since the organic matter was excessive, the arc spray was too strong, the followability of the slag was deteriorated, the bead shape and appearance were poor, and undercuts occurred. The amount of hume also increased.

On the other hand, 421 to 42 are examples of the present invention and satisfy all the requirements of the present invention, so they have high rod ratio, 1 class, amphoteric,
Undercarriage resistance, toe bead shape/appearance, bit resistance, blowhole resistance 1 Good mechanical properties and welding efficiency.

In addition, in Table 1, (a) Mn is JIS G 2301, FMn
Compounded from metal Mn with Mn1t 77 fb Ore-Mn corresponding to M2 and Mn amount 99.5- corresponding to JIS G 2311, MMn E.

(b) Iron powder is blended from iron powder with Fag 98% that corresponds to JIS H2601-1 type.

(Effects of the Invention) As described above, by using the coated arc welding rod of the present invention, it is possible to greatly increase the bead length and welding speed of the unit welding rod length, and horizontal fillet welding. This will make a significant contribution to increasing efficiency.

Procedural amendment Showa io year body month JO day

Claims (1)

[Claims] SiO_2: 15 to 30% by weight TiO_2: 1 to 4% by weight Total of one or two of CaCO_3 and MgCO_3:
2 to 6% by weight One or more of CaO, MgO, MnO, MnO_2: 1 to 10% by weight Al_2O_3: 1 to 5% by weight Na_2O and K_2O: 1 to 5% by weight One or more of FeO, Fe_2O_3 Total of 2 types: 6~
Covered arc welding characterized in that the periphery of the steel core wire is coated with a coating material containing 10% by weight of Fe: 30 to 60% by weight, Mn: 3 to 10% by weight, and organic matter: 0.6 to 1.5% by weight. rod.