JP2788847B2 - Low moisture cesium raw material for welding materials with excellent moisture absorption resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cesium raw material for a welding material, and more particularly, to a low-moisture cesium raw material for a welding material having less moisture and excellent moisture absorption compared to a natural cesium raw material.

[0002]

2. Description of the Related Art Reducing the amount of fumes generated during work in arc welding requires the use of a welding work from the 3K workplace and environmental protection, which has been of increasing interest in recent years. This is one of the issues that must be cleared.

On the other hand, in the welding industry in recent years, semi-automatic welding has been becoming mainstream from covered arc welding rod (SMAW), which has been the mainstream in the past. For the SMAW, Ri Contact and shown in JP-B-55-42672, the coating agent is low fuming is achieved by (flux), semi-automatic welding wire, in particular fume generation amount is large flux cored wire (FCW) For details, see JP-B-59-4415.
As shown in No. 8, although a technology for reducing fumes by adjusting the components of hoops has been established, a technology for reducing fumes in terms of flux has not been established, which has been one of the problems of FCW.

[0004] Fume is oxidized when high-temperature steam is rapidly cooled, and is generated by agglomeration. The generation place is mainly a molten pool, a suspended droplet, an arc column, spatter, and the like. As shown in the above-mentioned JP-B-59-44158, as one means for reducing the amount of fume, turbulence of the molten pool and suspended droplets is reduced as much as possible by stabilizing the arc (as a result, spatter is also reduced). However, from this, it can be easily estimated that the addition of a strong arc stabilizer reduces the amount of fume.

[0005] From such a viewpoint, as a strong arc stabilizer, cesium (Cs) having the lowest ionization voltage among naturally occurring alkali metals as disclosed in JP-A-3-166000 is known. As conceivable, Japanese Patent Laid-Open No. 3-16
No. 6000, cesium titanate, cesium chromate, cesium carbonate, and the like have problems such as high raw material moisture and poor moisture absorption resistance.
In particular, FCWs with seams (with seams) are often exposed to the atmosphere before welding, and therefore have a problem of moisture absorption resistance. When the water content in the wire is high, it is natural that defects occur in the weld metal.However, even when it is within an acceptable range, the water content in the wire suddenly boils during welding, and the arc blows out. Has the effect of increasing the amount of fume. As described above, in the case of the Cs raw material described in JP-A-3-166000, although the arc is stable, there is a problem that the amount of fume is increased because the moisture in the wire is high.

[0006] The present invention provides a cesium raw material as a strong arc stabilizer having excellent moisture absorption resistance and low moisture in order to solve the above-mentioned problems of the prior art and reduce the amount of fume generated during welding in arc welding. It is intended to be.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have focused on relatively low-cost and easily available raw cesium ores, and have repeated numerous investigations and studies on these raw materials. As a result, the present invention has been made here.

That is, the present invention provides an oxygen atmosphere 1000
Extracted and quantified at K.C. F (Karl Fischer) moisture is summarized as low moisture cesium feedstock welding materials having excellent resistance to moisture absorption, characterized in that one that is pre-treated to be 2000ppm or less.

[0009]

The present invention will be described below in more detail.

As a naturally occurring cesium raw material, there is cesium raw ore and the like, but it has a problem that it has a large amount of water and has extremely poor moisture absorption resistance and cannot be used as a raw material for welding materials.

Therefore, as a result of numerous investigations and examinations, it has been found that the pretreatment of natural cesium raw ore, that is, the KF (Karl Fischer) moisture extracted and quantified at 1000 ° C. in an oxygen atmosphere becomes 2000 ppm or less. It has been found that it is effective to use a pretreated low-moisture cesium raw material.

The raw cesium ore mentioned here is CsAlS
Porous ore (pollux ore) as shown in i ₂ O ₆ , Cs ₄ Al ₄ Si ₉ O _26, etc.
a, K, Rb, Mg, Ca, Sr, Ba and the like may be contained.

Until now, porcite ore has been used as it is, but porcite ore having a layered structure contains interlayer water between layers. Naturally, pits and blowholes are formed in the metal, but this has particularly caused an increase in the amount of fume.

The water in the porcite ore is supplied to an oxygen atmosphere 10
Extraction at 00 ℃ · quantify the K. F (Karl Fisher)
It is pretreated so that it becomes 2000 ppm or less with water.
Examples of the pretreatment include vacuum degassing and heat treatment (heating treatment such as firing or melting / crushing treatment).

The method for measuring the water content of KF (Karl Fischer) is defined in JIS K0113-90, and the water content is determined by a coulometric method of extraction at 1000 ° C. in an O ₂ atmosphere.

The porcite ore pretreated to have a water content of 2000 ppm or less of K.F.
Also excellent in moisture absorption resistance. This is because the decrease in the amount of interlayer water increases the bonding strength between the layers and makes it difficult for water to enter between the layers, that is, to absorb moisture.

The porcite ore thus pretreated is as follows:
For example, as shown in FIG. 1, 30 ° C., 80% (relative humidity)
, The KF (Karl Fischer) moisture can be maintained at 2000 ppm or less. It can be seen that the pretreated porcite ore has excellent moisture absorption resistance, as compared to the natural porcite ore which originally has a large amount of water and continues to increase by absorbing water as the storage time elapses.

A preferred porcite ore has a P (phosphorus) concentration of 1000 ppm or less, more preferably 7 ppm or less.
It is a porcite ore that has been pretreated so as to be less than 00 ppm. When the P concentration in the porsite ore becomes 1000 ppm or more, there is no problem when the addition amount of the porsite ore to the welding material is 2 wt% or less, but when it exceeds 2 wt%, the P concentration in the weld metal becomes high. The problem of hot cracking arises. From such a point, a preferable condition of the porcite ore is a case where the P concentration in the porsite ore is set to the above-described condition.

[0019] Cesium raw material of the present invention, SMAW (covered electrode), can be used as a normal powder to the weld material typically such FCW (flux cored wire), depending on its particle size, amount and the like applications Can be determined as appropriate.

For example, the particle size is 48 mesh or less (20
0-mesh or less is desirable). When the particle size is larger than the above range,
The cesium raw material is difficult to uniformly disperse, and the arc stability of the welding material is inferior. Conversely, when the particle size of the cesium raw material is 200 mesh or less and more than 80%, the cesium raw material becomes too fine, the specific surface area of the cesium raw material increases, and the moisture absorption resistance deteriorates.

The amount of flux added to fluxes such as SMAW (covered arc welding rod) and FCW (flux-cored wire) is desirably 0.01 wt% or more and 10 wt% or less. 0.01wt
%, The effect as a low fume is not seen, and if added more than 10 wt%, the amount of slag becomes too large, slag precedes at the time of welding, and defects in slag entrainment tend to occur. A more preferable range of the addition amount is 0.1 wt%.
Not less than 5 wt%.

Table 1 shows an example of the flux composition. The cesium raw material of the present invention is added to a flux having such a composition, and adjusted with a slag forming agent.

[0023]

[Table 1]

Next, an embodiment of the present invention will be described.

[0025]

【Example】

The natural porcite ore is subjected to a calcination method under various conditions as a pretreatment to prepare cesium raw materials (porcite ore) having various KF water contents as shown in Table 3.
Powder of 48 mesh or less was used as a raw material.

5% by weight of the above cesium raw material (porcite ore)
The flux for the added FCW (flux-cored wire) was replaced with a mild steel hoop (chemical composition shown in Table 2, 0.9 mmt × 13).
(mmw), a flux rate of 16 ± 1 wt%, and a high alloy steel hoop (SUS304, 0.4 mmt × 9 mmw) with a flux rate of 22 ± 1 wt%, and FCW (wire diameter 1.2 mmφ) was produced. The flux composition is as shown in Table 1.

The moisture absorption resistance was determined by sampling a cesium raw material as a sample in a weighing bottle as shown in FIG. 2 so as to have a sample height of 5 mm, absorbing moisture under the following conditions, and measuring the mass (moisture absorption) of the sample. It was measured (the tare weight was measured in advance). Table 3 shows the results. The KF (Karl Fischer) water content is based on JIS K0113-90, and the oxygen atmosphere is 100%.
Extracted and quantified at 0 ° C.・ Preliminary drying: 110 ° C. × 2 hours ・ Hygroscopic condition: 30 ° C. × 80% (relative humidity) × 48 hours
(Leaving time)-Measurement of moisture absorption: Measurement of KF (Karl Fischer) moisture-Evaluation of moisture absorption: ((less than 800 ppm) ○ (800 ppm or more and less than 2000 ppm) △ (more than 3000 ppm and less than 10000 ppm) × (10000 ppm or more)

The measurement of the fume amount is performed according to JIS Z 3930.
Performed in accordance with the method specified in Fume amount is downward
Weight when arc is generated for 1 minute in vertical posture (mg / min)
Was measured. Welding was performed using various FCWs having a wire diameter of 1.2 mmφ with an appropriate current and an appropriate voltage. The fume amount was evaluated based on the following criteria based on the reduction rate (%) from the fume amount of the conventional FCW (Test No. 1 in Table 3). Table 3 shows the results. ◎: reduced by 30% or more ○: reduced by 25% to 30% (including 25%, not including 30%) △: reduced by 10% to 25% (excluding 25%, 10%) ×: reduced by 10% 0% reduction

In Table 3, No. 1 is a conventional example using a natural cesium raw material (porcite ore).
The K.F. moisture content is as high as 15000 ppm, and the moisture absorption resistance is poor. No. 2 is an example in which the KF water content is 6000 ppm, and has poor moisture absorption resistance. No. 3 is an example in which the KF water content is 3000 ppm, and although the moisture absorption resistance is improved, it is not sufficient.

On the other hand, among the examples of the present invention, No. 4 is a cesium raw material having a KF water content of 2000 ppm (porcite ore).
Which has good moisture absorption resistance and reduced fume amount. No. 5 is an example in which the KF water content is 1000 ppm, the moisture absorption resistance is good, and the fume amount is reduced. N
No. 6 is an example in which the KF water content is 500 ppm, the moisture absorption resistance is extremely good, and the fume amount is further reduced.

In the present embodiment, the firing method was used as a method for reducing the amount of water in the porcite ore.
Since the present invention is based on the water content in the porcite ore, it is not affected at all by the water content reduction method itself.

[0033]

[Table 2]

[0034]

[Table 3]

[0035]

As described in detail above, according to the present invention,
Since a low-moisture cesium raw material having excellent moisture absorption resistance is provided, the amount of fume generated during welding in arc welding can be significantly reduced, and the use effect as a strong arc stabilizer is large.

[Brief description of the drawings]

FIG. 1 is a diagram showing the hygroscopic properties of natural porcite ore and the porcite ore of the present invention.

FIG. 2 is a diagram illustrating a moisture absorption test method.

Claims (4)

(57) [Claims] 1. A welding material having excellent moisture absorption characteristics, which is pretreated so that the KF (Karl Fischer) moisture extracted and quantified at 1000 ° C. in an oxygen atmosphere is 2,000 ppm or less. Low moisture cesium raw material. 2. The welding with excellent moisture absorption resistance according to claim 1, wherein the KF (Karl Fischer) moisture when left in an atmosphere of 30 ° C. and 80% (relative humidity) for 48 hours is 2,000 ppm or less. Low moisture cesium raw material for materials. 3. The low-moisture cesium raw material for welding materials according to claim 1, having a P (phosphorus) concentration of 1000 ppm or less. 4. The low-moisture cesium raw material for welding materials having excellent moisture absorption resistance according to claim 1, wherein a natural cesium raw ore mainly containing porcite ore is pretreated.