JP3429150B2 - Non-low hydrogen coated arc welding rod - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] TECHNICAL FIELD The present invention relates to the use of a high current
Is a non-low hydrogen coated arc welding rod (ex.
Below, referred to as non-low hydrogen rods). [0002] 2. Description of the Related Art Non-low hydrogen rods are used for low hydrogen coated arc welding.
Because the amount of diffusible hydrogen in the weld metal is larger than that of the rod
Crack resistance and impact toughness of welded materials with large constraints are poor
Welding of arc state, slag peeling property, bead shape, etc.
Widely used for general mild steel due to good workability
This is well known. By the way, like this
Non-low hydrogen rods aim to improve welding work efficiency
Often used at high currents. However, non
In the coating material for low hydrogen rods, secure an appropriate arc force and
To prevent nitrogen and oxygen from entering the weld metal
Organic substances such as loin and starch are contained, so high current
When welding, the coating material in the latter half of the welding rod decomposes and burns with Joule heat
When the welding rod is burned, the so-called rod burning phenomenon occurs.
There is a disadvantage that it is easy to do. Welding of the part where this bar burn occurred
If a rod is used, the arc becomes unstable during welding and
Not only the workability deteriorates, but also blowholes and insufficient penetration
Welding defects occur. In order to solve the problem of non-low hydrogen rods,
Various proposals or implementations have been made. For example,
In JP-A-57-206595, water is used as a fixing agent.
SiO in glass_Two/ Na_TwoThe molar ratio of O is from 2.8 to
The use of 3.8 high-molar-ratio water glass prevents burning.
Stopped. However, Japanese Patent Application Laid-Open No. 57-100896
Increase the molar ratio of water glass as described in the report
And drying cracking of the coating is likely to occur in the drying process during manufacturing,
Also, as the molar ratio increases, Na_TwoO or K_TwoAlka such as O
Since the oxides decrease, the arc condition deteriorates and spatter
There is a problem that the scattering of the water increases. On the other hand, Japanese Patent Publication No. 63-7878 discloses
In some cases, the coating agent contains magnesium silicate, a hydrous mineral.
Adds piolite to improve coating adhesion and
Although the bar burning resistance has been improved when used in a stream, sepiolite
Has a limited amount of reserves and is suitable for versatile non-low hydrogen rods.
Is an expensive coating material. Thus, the current situation
Uses high current while satisfying various performances on non-low hydrogen rods
It is very difficult to improve bar burning resistance
there were. Working from the industry using coated arc welding rods
Non-low hydrogen type rods that are excellent in bar burning resistance from the point of efficiency improvement are strong
It was well requested. [0005] SUMMARY OF THE INVENTION The present invention
In consideration of the actual situation, we examine the coating material and use high current
Aims to provide non-low hydrogen bar with excellent bar burning resistance
And [0006] SUMMARY OF THE INVENTION The present invention provides such an eye.
Use of high current after various studies to achieve the target
Develops non-low hydrogen bar coating agent with excellent bar burning resistance
did. That is, the gist of the present invention is potassium feldspar
Is from 0.015 to 0.
060% by weight (hereinafter referred to as%), and the mineral content is 3.5 to 1%.
5.0% by weight, and a gas generating agent, an arc stabilizer,
Coating agent consisting of slag forming agent, deoxidizing agent and fixing agent
It is a non-low hydrogen rod which is characterized by being coated on a non-hydrogen-based rod. [0007] DETAILED DESCRIPTION OF THE INVENTION We use high currents
Investigation of raw materials for coating materials to achieve means of obtaining excellent bar burning resistance
Researched hard by Burning of coatings on non-low hydrogen rods
Uses organic substances in the coating of non-low hydrogen rods as described above
Of organic matter due to Joule heat during high current welding
It is mainly caused by decomposition and combustion. Therefore,
First of all, we thought that it would be better to reduce organic matter, but in this case,
Has a weaker arc force, causing welding defects and arc interruption
In the coating material for non-low hydrogen rods
Of organic matter is necessary in an appropriate amount,
And could not. [0008] Next, the entire coating material is made to have fire resistance, and
In order to prevent the phenomenon, the coating material has a high melting point source.
Magnesia clinker, dolomite, alumina
We considered the application such as. As a result, its effectiveness was recognized.
However, the arc voltage was too high and the arc voltage was too high.
Spatter increases, and the welding metal in vertical and upward welding
The genus becomes easy to hang and presents a convex bead and
The workability has deteriorated. In addition, the present inventors have developed a wet coating material.
Focus on the material, and the moisture is released from the coating material during welding.
The heat of vaporization promotes the cooling action, and the moisture
Since the arc voltage is increased and the melting rate is increased, the
The covering agent is not excessively heated, greatly contributing to the improvement of bar burning resistance.
I thought I could. Moisture referred to in the present invention is 300 ° C to 1
Moisture released when heated to 000 ° C, 300
Adsorption and adhesion moisture released when heated below ℃
It was not considered because the improvement was not effective. moisture
As a result of various studies on coating material containing
, Talc or potassium feldspar as the main components
It was found that the soil mineral exerted its effect. However, of these raw materials, the main component is
For clay minerals that are lite, sericite itself is an insulating ore.
Material, the re-arcability after arc interruption is greatly deteriorated
Problems and other disadvantages such as increased spattering
I did In the case of clay minerals containing talc as a main component,
Arc becomes unstable and spatters are scattered frequently.
In addition to the defects in the slag, slag flow can be caused by welding in a vertical position.
Mobility deteriorates and presents a convex bead.
Has deteriorated. On the other hand, clay minerals mainly composed of potassium feldspar
(Hereinafter referred to as potassium feldspar clay)
Greatly improves bar burn resistance without observing deterioration of welding performance
The effect has been shown. Rather, it is K for potassium feldspar clay._TwoO or N
a_TwoContains a large amount of alkali metal oxides such as O
Good arc condition and good slag flow
It was found that welding workability was improved. Also book
The potassium feldspar clay of the invention is a plagioclase (α-K) of potassium feldspars.
AlSi_ThreeO₈), Feldspar (β-KAlSi)_ThreeO ₈)
The main component is other soda feldspar (NaAlSi_ThreeO₈)
Or muscovite @ KAl _TwoSi_ThreeAlO_Ten(OH)_Two}and
Includes inclusion water obtained by heating at 200 to 800 ° C
However, these are raw materials having various contents.
Potash feldspar clay can be used alone or in combination of two or more
I also understood. Next, noteworthy in the present invention is potassium feldspar viscosities.
Obtained by multiplying the soil content by the water content in potassium feldspar clay.
Moisture in the coating agent (hereinafter called potassium feldspar release moisture)
Content) has a significant effect on bar burning resistance.
Can be remarkably improved as the value increases. Only
However, if the amount is too large, the arc force becomes strong, and the spatter increases.
Addition, slag encapsulation becomes poor,
-Since welding defects such as bur laps are likely to occur,
Finding the right amount of feldspar release moisture completes the present invention
This is the most important part of the process. Also, the content of potassium feldspar clay in the coating agent
Determines the content of water released from potassium feldspar and improves the bar burn resistance.
It contributes to goodness and is related to welding performance.
If contained, the alkali oxides will increase and the viscosity of the slag will decrease.
Slag encapsulation in horizontal fillet
The bead hangs in the up and down posture, causing deterioration in welding workability.
Therefore, it is important to find the proper content of potassium feldspar clay.
is there. [0014] First, the inventors of the present invention found that the potassium feldspar released moisture
The following experiment was performed to determine the appropriate amount. That is,
The water in Table 2 was applied to the two types of non-low hydrogen rod coatings shown in Table 1.
Are shown in Table 3.
Used in combination of one or more as described above.
The total content was changed from 5.4 to 14.2%.
Is 0.007 to 0.07.
The coating material changed to 4% was changed to 4.0 mm in diameter and 450 mm in length.
mm JIS G 3523 SWY11 steel core wire
Create 12 types of welding rods by coating and use an AC welding machine.
Welding performance was investigated using [0015] [Table 1] [0016] [Table 2] [0017] [Table 3]The bar burning resistance test of the coating agent is carried out by measuring the thickness of the mild steel sheet.
AC melting using 12mm, width 100mm, length 600mm
Welding is performed using a welding machine, and the current is 220
A was used. The judgment method is unique to non-low hydrogen rods.
Utilizing the welding phenomenon. In other words, non-low hydrogen rods are
When welding with high current because it contains
Deteriorates so that the coated cylinder is not suddenly formed, and
The arc state also changes suddenly and the part where the arc force starts to decrease
I will. Therefore, the arc is extinguished at that position,
The remaining welding rod length, that is, the remaining welding
Measured and the values were tabulated as the average value of 10 test rods.
80 mm or less was determined to be good. In addition, adjustment of welding workability
Inspection, board thickness 12mm, width 100mm, length 450mm
Of a mild steel plate in a T-shape, using an AC welding machine, and the current is horizontal.
Fillet uses 220A, vertical uses 160A, each
Investigate the arc condition, slag condition, bead shape, etc.
Was. The judgment is comprehensive judgment of each welding posture, good, slightly
Inferior, inferior. The results obtained from the above tests are shown by the circles in FIG.
Indicated by High electricity when the potassium feldspar release moisture is less than 0.015%
Poor bar burning resistance of the coating agent during diversion, 0.015% or less
Above, cooling effect by heat of vaporization when moisture is released from coating material
Is excellent and the melting speed is also fast, so it has excellent bar burning resistance
Sex has come to be obtained. The value is 0.060
%, The arc force becomes excessively strong and
The encapsulation of the rug deteriorates and the bead shape deteriorates and
An undercut occurs, and in the upright position, the beads
It became easy to sag and showed a convex shape. like this
As a result, excellent bar burn resistance while ensuring good welding performance
To obtain the properties, the potassium feldspar release moisture in the coating agent is 0.015.
It was found that it should be ~ 0.060%. Next, the action and range limitation of the components in the present invention
The detailed reason is described. (Potassium) Feldspar released moisture; 0.015 to 0.060%)
It is one of the aspects of the present invention to define the amount of water released from feldspar.
Are important parts, and when welding is performed at high current,
Enhances the cooling effect of heat of vaporization when releasing moisture from the encapsulant
And the melting rate also increases, so that the
Great for obtaining excellent bar burn resistance as it reduces heat generation
It has an effect on potassium feldspar release water of 0.01
The reason for setting the content to 5 to 0.060% is as follows. That is,
At less than 0.015%, the effect is not seen at all,
If it exceeds 60%, the arc force becomes too strong and the horizontal corner
The meat has undercut and overlap defects,
In the vertical position, the beads are easy to hang and welding workability is poor.
It becomes. (Potassium feldspar clay; 3.5-15.0%)
It contains 3.5 to 15.0% of potassium feldspar clay in the dressing.
Is important in obtaining good bar resistance,
Secure slag with good flowability
Therefore, there is also a purpose of ensuring good welding workability. 3.5%
If less, the arc is unstable and spatter increases, and slag
The bead shape is degraded due to poor fluidity. Also, 1
If it exceeds 5.0%, the melting point of the slag decreases, so
The fillet of the slag deteriorates with fillet, and the bead
And the welding workability deteriorates. In the present invention,
Gas generating agent, arc stabilizer, slag raw material in the coating agent used
Compounding agents, fixing agents and steel core wires are used for ordinary non-low hydrogen rods
Is what it is. [0022] EXAMPLES For the coating agent of Table 1, the potassium feldspar shown in Table 2 was used.
The diameter of the coating with a further change in the combination and content of the clay
JIS G 3523 of 4.0 mm and length of 450 mm
After coating and coating the steel core wire of SWY11, it is dried and dried.
Create different kinds of test welding rods and use AC welding machine to
Welding used in investigating the effect of potash feldspar release moisture as described
Depending on the conditions, measurement conditions, and judgment methods,
The welding workability was investigated. The results are shown in Table 4 and in FIG.
Shown by the value of the mark. In Table 4, welding rod No. 1 to No. 1
0 is an example of the present invention; 11-No. 20 shows a comparative example
You. The non-low hydrogen rod of the present invention has the following No. 1 to No. 10 is individual
Component satisfies the requirements of the present invention, and potassium feldspar release water
The content is 0.015 to 0.060%, and it is excellent in bar burning resistance
Has good welding workability. No. 11, No. 1
2, No. No. 18 is bar-burning resistant due to low potassium feldspar release moisture
No. 11 and No. In 18 the coating agent
Arc state because the content of potassium feldspar clay mineral in the soil is appropriate
The welding workability such as fluidity of slag and slag is good. N
o. In the case of 12, the amount of potassium feldspar clay mineral is small,
Poor arc stability in posture and increased spatter
Was. No. 15, No. 17, No. 20 is mosquito
リ It has excellent bar burning resistance due to the large amount of released feldspar, but
Is too strong and the bead is easy to hang in a standing position
It became a convex shape. No. In 20, potash feldspar
As there is too much clay, the melting point decreases and horizontal fillet
Problem of deterioration of slag encapsulation and bead drooping in vertical position
And the welding workability became extremely poor. No. 13, N
o. 14, No. 16, No. In 19, K-feldspar release
It is excellent in bar burning resistance due to the proper amount of water,
Welding workability was poor because the content of stone clay was not appropriate.
No. No. 14 has a low content, so the arc is particularly safe.
The qualities are poor. 13, No. 16, No. 19
Conversely, because of its high content, poor slag encapsulation of horizontal fillets
Bead becomes convex bead.
It became a convex bead. [0025] [Table 4] [0026] As described above, the non-low hydrogen of the present invention
The system rod has significantly improved bar burning resistance, and
We can provide a welding rod that ensures contact workability,
In addition, high current can be used, so welding work efficiency
Can greatly contribute to improvement.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram investigating the effects of changes in the potassium feldspar release moisture in a coating agent on bar burning resistance and welding workability.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B23K 35/365

Claims (1)

(57) [Claims 1] Water content of a clay mineral mainly composed of potassium feldspar is 0.015 to 0.060% by weight, and the mineral is 3.5%.
-15.0% by weight, and a coating agent comprising a gas generating agent, an arc stabilizer, a slag generating agent, a deoxidizing agent, and a fixing agent is applied to a steel core wire, and the non-low hydrogen is characterized by being coated. Series coated arc welding rod.