JPS58179597A - Production of low hydrogen covered arc welding electrode - Google Patents

Abstract

PURPOSE:To improve the operability of welding using a titled welding rod and the productivity of the welding rod, by coating a covering material compounded with a prescribed amt. of an oxidized material of Fe-Si consisting of FeSi, FeSi2 phases on the outside of a steel core wire. CONSTITUTION:The Fe-Si which contains 20-50wt% Si and consists substantially of an FeSi phase and an FeSi2 phase alone is subjected to an oxide film treatment. The covering material contg. 8-25wt% such oxidized Fe-Si is coated on the outside of a steel core. The operability of welding using the above-mentioned welding rod and the productivity of the welding rod are thus improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a low-hydrogen coated arc f# seeding rod. The present invention relates to a method of manufacturing a low-hydrogen-based coated arc welding rod with good welding workability with high productivity by applying a blended coating material to the outer periphery of a steel core wire.

F.-8i is commonly used as an eIt agent raw material for low water bulk coated arc S* rods. The reason for this is that Fe-51 is extremely excellent as a deoxidizing agent and also has a favorable effect on welding workability, such as having the effect of adjusting the viscosity of the II# molten pool. However, the disadvantage of Te, which adds 11 tons to the productivity of the low water bulk coated arc S* rod and the workability of the bath pot, cannot be ignored.

■When manufacturing I# grade rods, KFe-5i and water glass react and the adhesion ability of the water glass decreases, so the adhesion strength of the coating after drying is poor, and when transporting tb, m products or melting! I+ The coating may fall off during on-site handling, making it unusable. During the drying process, H2 gas is generated by the reaction between KF62S1 and water glass, which causes cracks and blisters in the cover 41, significantly reducing its commercial value.

(2) Fe-6i tends to increase the I- particles generated in the f# class and to make the particles larger (To), which causes a decrease in the workability of low water bulk coated arc welding rods. Furthermore, the shape of O-S** during melting is also very unstable compared to general coated arc welding rods, and is more likely to cause defects.

However, since Fe-5i is an essential component as a coating material raw material for a low-hydrogen coated arc stabilizer, and is a component that is mixed in a fairly large amount, it is necessary to solve the above-mentioned problems in some way.

The inventors of this project focused on the above-mentioned circumstances, and with the aim of improving the disadvantages of PE-SI while retaining its advantages as described above, they have carried out research by putting pressure on the Pa-8i organization. picture. The present invention was completed as a result of such research, and its structure is that Fe-8i containing 20 to 50 weights of S1-containing NjA is treated with an oxide film and then coated! In the method of manufacturing a low hydrogen-based coated arc #lIl rod by applying a coating material containing 3 to 25 weight bags per total electric charge to the outer periphery of the steel core wire, the F.-si and pesi phases and p1
There is an advantage to using a 5si two-phase structure.

Fe-8i used for welding rods as described above is usually treated with an oxide film beforehand and then kneaded with other coating components, but in the case of using ordinary Fe-8t, the above As shown in (1) and (2), low-hydrogen-based coated arc I# is able to sufficiently improve the performance of the rod. However, as a result of our experiments, we found that if we use F・-51 that consists of only yesi phase and F8Sj two phases and does not substantially contain metal ST, it is possible to prevent the above-mentioned problems associated with the combination of F・-8t. That was mg. Although the reason for such a result has not necessarily been clarified, it is believed that the trace amount of metal ST mixed in F-8i is likely to have an effect on the occurrence of the above-mentioned ① and ②O failures. L! This is also clear from the iI examination detailed below. Here, including metal Si, 1 @vFe −s
i Toha 1 For example @1 [! k (Xm diffraction chart) shows tlo (F@Smu phase prisoner and y@si2 phase (ye which shows only the seagull diffraction peak and does not show metal SiO diffraction peak)
-8it says. In contrast, commonly used Fe-
For example, Si is as shown in Fig. 111 (same ill) 2) as (FsSmu phase (A) and hiF@Sig phase Om gold jll! Ii (b)
The diffraction beater is shown.

The F・-Si used in the present invention has a Si ratio of 2
It is necessary to use a material with a Si content of 0 to 60%, and if the Si ratio is less than sIO, the blending ratio of PE-5I will be high and the price of the welding rod will rise. On the other hand, if the weight ratio of bO is exceeded, there is a tendency for the metal to segregate as metal 5i during blending. In addition, the F・-840 particle size composition is not particularly limited, but the performance of the # binding rod is further improved! One of the requirements is h174μmφ in order to
It is desirable to use the following items with 20 to 75 weight bags. However, if there are many coarse particles than the above particle size structure, the strength of the coating will be poor and the coating will easily fall off when transporting the welding rod or during entertainment (on the other hand, if it is too fine,
Since the specific surface area of si- is too large, the reactivity with water glass increases, and the coating often swells and cracks during coating drying, resulting in a decrease in productivity. However, with the above particle size configuration, ye-s
By using i, the above-mentioned relationship will not occur, and the strength of the spraying during the spread of the arc of the melting rod will be appropriate, the arc will last well, and the amount of spatter generated will be low. You can get an arc bath loose rod.

t*F@-si is used by carefully mixing it with coating materials such as slag forming agents, arc stabilizers, and fixing agents, but the F・-8i content in the amount of coating material is 8. The QI is set in the range of ~26 weights.

However, if F.-85'1k is less than 8% by weight, the deoxidizing effect will not be sufficiently exhibited, leading to the occurrence of welding defects in the prohoe, while if it exceeds 26% by weight, 05i will be absorbed into the weld metal.
The amount of opj#Iiυ increases, the f# pot metal becomes hard, and the mechanical strength becomes poor. Alternate iron powder is extremely useful as a component to improve S* efficiency, but please be aware that if the content exceeds 60 weight bags in the total coating material, the insulation of the coating will deteriorate and safety problems will occur. Should.

The above is an overview of F.-81 to be blended into the coating material.Next, we will explain the basis for selecting F.-si consisting of Feiii phase and resin phase (not containing metal Si) in the present invention with oxidation #! Based on the experimental results regarding the degree of expansion, the amount of shedding of the coating, the productivity of the covered rod, the welding workability, etc.

First, Table 1 summarizes the F・-8i0 relative composition and particle size composition used in the experiment below.
・-510, symbol A is F・-8i consisting of only pesj phase and F・stg phase (xi1 diffraction char in Figure III) pe-5i containing St (
Fig. 2 Sample of Ox re-diffraction charge) is shown in 1.

[Oxidation degree lII formation degree]

Method 5: Soak the sample PE-ST powder in NaOH water for 6 minutes, then dry at about 100°C to 961,700°C.
2) Oxidizing $8! Medium-t" 10 Ga1l heat treatment is increased.

Oxide film formation degree measurement method 10gK of F・-8も powder whose oxide film was destroyed by the above O'j5 method, specific gravity 1.41) V-)/-da water glass was added, and the amount of H2 gas generated was measured. -bX1◎Measure the time (minutes) until CCK is reached, and take this time as the degree of oxide film formation. Therefore, the larger this value is, the better the stability against water glass is.

The results are shown in Fig. 8), and the stability against water glass containing metal SI is extremely superior to that of conventional products. 3
By using 1, it is possible to eliminate the above-mentioned problems caused by water glass and OK reaction. tkJp・-Si
Therefore, it is better to make 70 gold without gold and fat 5 and 140, but among them, less than s16 weight can be made into normal V.
It is possible to obtain a sufficient effect even if the material is replaced with -Si. The influence of the particle size composition is not consistent with that of pre-malted rice.

0 metal in 1ce-si! i! It is understood that the absence of 1011 has a much greater influence on the temperature (due to the grain size structure of the sample).

[Amount of coating falling off]

Dimensions of test rod: 6. (1 mφ
-Mlmg-1 wheat flour 4.5, V-chiel 6 excellent, F.-5ゑ8Is%704- 4- Dropping test method Insert the test rod into a steel pipe with a nominal diameter of 40tmφ
The coating is dropped from the 06110 position, and the weight of the coating that falls off is 0, which is defined as the amount of falling off. Therefore, the lower the amount of deforestation, the better the quality.

The results are shown in Figure 4, with Haruka p and conventional F-8i (
When gold MSiAJ7) is used, the amount of shedding Fi is extremely large, but when F-5A without metal Si is used, the amount of shedding becomes extremely small. When all of the F@-8i used for dual use were made without metal Si, the results on the back of the umbrella were obtained.
If the amount is less than 2 & weight, it will be difficult to obtain almost the same level of shedding amount even in 9 cases by using ordinary F.-8i in combination.

Although the influence of the grain size structure is not significant for #II metal Si, there is a tendency for the amount of grain removal to be smaller when the grain size is slightly finer.

[Productivity of coated rod]

Dimensions of test bar = -0 ■φ x 450wm1 Coating material composition: Productivity test method same as in the case of shedding amount test Coating material was applied to the outer periphery of the core wire and dried in a drying oven at 120℃ for 80 minutes.
The outside of the coating after drying for a minute and then forming at 400'C
Visually observe the Il, discuss any cracks or bulges, and determine productivity as the percentage of Kushima bars (good products). Therefore, the higher the non-defective rate, the higher the productivity.

The results are shown in Fig. 5. F・-5 without metal Si
The use of I and K can greatly increase productivity. In the case of the above-mentioned test O, it is also possible to use metals 5iTo and 10F.-5i in combination if the amount is less than 2S by weight.

1141 Productivity] Dimensions of sample rod 1rr: 4.0swφX40G+w'fIEialj
iF & (Regret at Heavy 1): 'It's sour vvt Muro 4
Sac, Fluorite 18vI, F・-Mn4 Sorry, Lucie A/7 Sorry, F@-8i14 Sorry, Others 511 WI11 Workability Judgment Method Using each test rod obtained above, JIS Gjl106, Yang 5@A , 1! Cod tOT type joint #contact current 160
Amp, A, and C are used for upward melting and the following items':)
I made an overall judgment.

(1) Arc stability, (Liata tolerability, (1) Arc O concentration %14) Talator spread p, (5+7W droplet transition llB% (The results of conformity with the side base material are shown in Figure 1. [Haruka] shown in p, F・- without metal St.
If you use sl, NI! 1. Workability can be significantly improved. As long as the amount is less than 2S, even if the conventional metal S-310F-51 is used in combination, it is possible to achieve the same level of A'0 soybean production.

[Effects of the presence or absence of O metal S in F・-81 on other coating systems] The above experiments are almost the same.The effects of the coating IAKIILlt* and 40 were investigated, but also on other oImj1o@@ systems. A first-order experiment was conducted to clarify the significance of F without metallic Si.

Dimensions ti of the test rod: C-1 to J1=4. &11m16J summer 818
212 DKO18D-1~g-6, --JI821
1112 D5026-1~g-6, --JIS! 1
111! D50$! 6F-1~g=4. kad J
Sumire8ZJB! Is! D501g 41 agent composition: 2nd
However, as F Tom 4 Mu, 11!
Table 8 shows the results.

As is clear from the results in Table 2, 0FI without metal Si
-! The effect of selecting if is effectively exhibited for any coating system of the low-hydrogen coating arc bath 110.

[Brief explanation of drawings]

The 1st factor is the x11 diffraction chart of Pe-5ゑ, the 8th ~
Figure 6 is an experimental graph showing the relationship between the -F/-$lO blending ratio, which does not contain metal 81, and the hardness of the hardened skin (I11 type bottom), the amount of coating O falling off, the yield rate (C productivity), and the fertilization quality (O). It is. Figure 3 Mixing ratio of pe-5i (weight%) Figure 4 0 25 50 75
100 Figure 5 (Mixture of A-1 and B-1) Figure 6 0 25 50 75
100 (mixture of A-1 and B-1)

Claims (1)

[Claims] F・-3i with a 11184 content of 20 to 60% by weight
After forming the tin oxide layer, add 8% of this to the total weight of the coating material.
~i! In the method of manufacturing a low hydrogen-based coated arc rod by coating MilK on the outside of the steel core with a coating material mixed with 6 weights, 1res i phase and Fe51g as the F-8i.
1. A method for producing a low water bulk coated arc welding rod, characterized by using a coated arc welding rod consisting of a phase.