DE1931196C - Core electrodes for fully and semi-automatic arc welding - Google Patents

Description

The invention relates to a core electrode for fully and semi-automatic arc welding to achieve a non-austenitic mild steel or alloy steel weld with improved notched impact strength, consisting of a tubular steel shell and a core.

Core electrodes are usually made by cutting a thin strip of iron or steel a tubular sheath and core materials are enclosed within the sheath. Such electrodes are used in submerged arc welding processes, in gas-shielded metal arc welding and used in self-protection metal arc welding. Depending on the requirements the process and the chemical and physical properties desired in the weld metal the core materials are selected from six general classes, which are listed below with Examples are shown.

Core materials Examples Bow stabilizers Titanates of potassium and on their metals, Silicofluorides of potassium and other metals, Fluoaluminates of sodium and other metals, Flux Fluorides of calcium, Na trium and other metals, Atmospheres Carbonates of calcium, ba producer rium and other metals, Carbon, Deoxidizer Manganese, Ferromanganese, Silicon, Ferrosilicon, Aluminum, Titanium, Titanium ferrous alloy, Zirconium, Metals and Nickel, Metal alloys Chrome, Ferrochrome, Ferromolybdenum, Steel powder, Iron powder, Metal oxides found in sweat arched at least partially are reducible, e.g. B. the Metal oxides of manganese and nickel, Slag generator Silicon dioxide, Rutile, Feldspar, Wollastonite, Zircon, * Zirconia, Oxide residues from I carbonates.

The slag formers of the last category include core materials that go up in the welding slag, after they have fulfilled their primary function. These materials also include slag bulking agents, such as B. Minerals such as wollastonite, which are added to the slag to a preferred and set a volume that is not critical for the electrode behavior. Such optional additives included in their Welding functions are neutral are not considered in the description of this invention.

A single core material can serve more than one function. For example, an alkali metal titanate bond stabilizer can also become a slag generator; a metal carbonate can be an atmosphere generator and the metal oxide residue then becomes a slag generator; Ferrotitanium, a strong deoxidizing metal, can also act as an arc stabilizer.
The core materials usually make up 10 to 60% of the finished electrode and, together with the shell and the external atmosphere or the flux, determine the chemical and physical properties of the finished weld.
During the development of soul electrodes for

such automatic arc welding was the porosity control in certain systems and compositions an unsolved problem. Electrodes have been developed and sold that are different for each Welding processes are suitable in which the type and quantity of the above-mentioned core materials are correct were selected. These electrodes rely largely on the use of well-balanced Deoxidation metal contents; and the composition of the core to achieve the desired Results are well known in the art; A wide variety of proposals have been made for this so far. Another problem which has persisted until the invention is how to achieve the desired ones Toughness in the weld seams created by the well-known core electrodes. The austenitic Steels generally have moderate strength but good ductility and impact resistance. Tubular electrodes produce welds that have these desirable properties and which can be used without inconvenience. However, they are not austenitic Electrodes, especially mild steels and high-strength alloy steels, that are formed by deposits are characterized by martensite-bainite-ferrite weld seams, the consumer often not satisfied. The arc welding technology can now deliver electrodes, the porosity-free deposits with physical properties that are satisfactory with the exception of impact strength

so are. Consumers are however persistent Requires weld seams with a higher and even higher notched impact strength. For example, at In many applications of mild steels and alloy steels, the toughness of the weld metal is measured by the Charpy V notch impact test, the critical property. If the weld doesn't has the desired toughness, then an object made with it can break during use, which can have catastrophic consequences.

For example, electrodes must meet the highest toughness requirements of test standard AWS A5.18-65T (ASTM A 559-65 T) for mild steel electrodes for gas-shielded metal arc welding have a minimum weld metal Charpy V-notch impact strength (impact energy) of 2.8 mkg at -29 ° C. Other classifications that are covered by this test standard have less stringent requirements. However is for many applications this toughness value of

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2.8 mkg at -29 ° C is insufficient, and there is the addition of magnesium along with manganese considerable difficulties in developing and silicon or manganese, silicon and titanium pre-electrodes, which is written about these minimum requirements and that, in addition, a club substantial amount. improvement of the properties of the weld seam does not The Charpy V Notched Impact Test Conditions 5 is considered. An anticipation or can always be made stricter by making the subject matter of the invention obvious Temperature - at which the test is carried out, publication is therefore ruled out. is lowered. The lowest temperatures are soul electrodes are also from the UK used when the weld seam is known at low tem- patents 1,079,710 and 1,090,049, temperatures should be used or if an io which may also contain magnesium Greater security for a weld may be required, but the special composition will which are used at normal temperatures of the marine electrode according to the invention in these target. References are not mandatory or are close to

Of the three above automatic welding laid.

processes in which core electrodes are used 15 In the following, the invention is to be explained with reference to some, the submerged arc welding requires embodiments to be explained in more detail: of the electrode least; it must only elements soul electrodes according to the invention, in which for the desired chemical composition of up to 1% of magnesium contained 0.3 and 18 provide up to 26 ° / ₀ weld plus Desoxydationsmetalle because of a mixture are present, which, in weight other functions of flux be concerned, ao percent of the electrode, has the following composition: In the other methods, the core electrode,.
additional. Materials from the ° ^1S listed above. ^z ""»;? »That fulfill additional functions. In the JJ »*?! ^s l't . " Technique of the selection of the electrode ^{core composition- JJ »J? I s} V'J {· Settlement, which the desired functions in the as Λ? '° £? ^s M / ο most favorable way met, there is a great experience. xLu-t'Jl ^ t? ™? * This experience has led to commercially available electrodes in °> ^{03 bls} ° ' ¹⁰ ' 0 carbon, of each category, which are considered to be successful core electrodes according to the invention in which the core is currently required and which are up to 1.5 ° / ₀ meet at least one sheet stabilizer nisse. 30, which consists of an alkali metal titanate, but an urgent need for electrodes, alkali metal silicofluoride and an alkali metal aluminum, non-austenitic steel welds with a minat.

result in higher impact strength; This need according to the invention core electrodes, in which 0.2

exists in particular in that part of the up to 2% magnesium, up to 1.3% of the arch stability

consumers, the metal sheets or plates with better properties crystallizer 35 and 4 to 24 ° / ₀ of the above-mentioned

use shafts as the weld. Mixture are present.

It has now been found that core electrodes, core electrodes according to the invention, in which 0.3

which in one of the automatic welding processes up to 1% magnesium, 0.1 to 0.4% of the arc stability

should be used and the welds with sators and 9 to 17% of a mixture present

resulting in increased impact strength, the following, in percent by weight of the electrode

if a small percentage has metallic composition: cal magnesium is added to the core materials. The magnesium can be in pure or alloyed form present, and to make room for this magnesium

a small change in the iron powder content can be made,

which is commonly used as a filler. J Z? A 01

The subject of the invention is therefore a soul '.J? "''£ ^is f? _

electrode of the type mentioned at the beginning *, which thereby ° ^{'03 bls} °' ¹⁰ '· ^Kol "enstoff.

is characterized in that the core in percent by weight 50 core electrodes according to the invention, in which the

the electrode of 0.3 to 1% magnesium and 9 to core up to 9% alkali or alkaline earth metal fluoride

18% of a mixture contains.

η λ u- λ no / er · soul electrodes according to the invention, in which 0.2 to

η2 u- ^S ,! i ° Si'icium, ₂ o _{lo magnesium>} O _{7 to 3} «./e _of the alkali mentioned

n? u- ^S \ 'lJ, ° w ⁸ ?? ^ 55 or alkaline earth metal fluoride and 12 to 35% of the

K S "X * 5! 'Molybdenum, mixture are present.

1 u- ^S Wkl? χ, -? T 'Core electrodes according to the invention, in which 0.3

i , "', 7 ?. ^{/ o} ™ ckel, _{to lo / o} magnesium, 1.4 to 2.3% of the alkali or

η ^ u- TL ·, i ^{1S!? U} «alkaline earth metal fluoride, and 17 to 23% of a

0.03 to 0.10% carbon are esend _6o π, ^^ _ANW that, in weight percent of the

consists. Electrode, has the following composition:

From the German Auslegeschrift 1 236104 is

already known a core electrode, which is made of up to 0.5% silicon,

tubular steel jacket and a core. 0.4 to 1.2% manganese,

Here, the addition of a deoxidizer 65 0.3 to 0.8% molybdenum,

from the group calcium, magnesium and zirconium 0.6 to 1.3% nickel,

suggested. 14.5 to 22% iron and

However, a review of this document shows that 0.03 to 0.10 percent carbon.

0.4 until 0.9% Silicon, 0.6 until 1.6% Manganese, 0.2 until 0.6% Molybdenum, 0.2 until 0.7% Chrome, 1 until 2.2% Nickel,

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Core electrodes according to the invention, in which 0.3 direction of metallic magnesium does not remove up to 1% magnesium, 0.1 to 1.1% of the arc stability - the generally known unfavorable effects on sators, 3.5 to 6% of the alkali or alkaline earth metal Welds of excess amounts of such fluoride, 0.6 to 1.3% of said alkaline earth metal elements such as phosphorus, sulfur, titanium and Alucarbonats and 9 to 18% of a mixture present 5 minium. In order to achieve maximum benefit, that, in percent by weight of the electrode, must have the following practices of healthy metallurgical composition: principles and other rules known in the welding technique , according to how before being observed

η * w ι'ί.1 χμ ^{Um> and} ^ e chemistry of the weld seam must be related to the

η α k- ^S η'V / ⁰ χΓ? ^ ¹⁰ carbon and alloy content according to the

"· *?! ^S "', ^lo molybdenum, desired strength values can be set,

η λ, Ü ' ^S η L ·, £ "5? - Metallic magnesium must be used in automatic soul

0.03 to 0.30% carbon. electrodes are used with care and as specified

Core electrodes according to the invention in which 0.3 become, but when it is used in this way, up to 1% magnesium, 0.1 to 1.1% of the arch stability - then significant improvements in the kerbsator, 3.5 to 6% of the alkali or alkaline earth metal impact strength of the welds is achieved. If metalfluorids, 0.6 to 1.3% of the alkaline earth metal carbonate lisches magnesium according to the teachings of the invention and 9 to 18% of a mixture used is present, particularly in sweat Percentage by weight of the electrode, the following additional seams marked improvements that are already in accordance with composition has: ao the older standards were good. No advantages

were used in the use of metallic magnesium in titanium dioxide-based core electrodes of the lowest grades found, the welds of which have high concentrations of deoxidation-25 retain metals to withstand porosity in all welding conditions, and whose notched impact strength is very low. From a metallurgical point of view, such welds are cannot be improved, and magnesium acts up to 1% magnesium, 3.5 to 6% of the alkali metal or merely as an additional deoxidizing metal. One Alkaline earth metal fluoride, 0.6 to 1.3% of the alkaline earth core electrode containing magnesium alone would be metal carbonate and 9 to 18% of a mixture worthless. However, if you have a non-austenitic are present that, in percent by weight of the electrode, takes the electrode, its composition already has the following composition: the current requirements for core electrodes

_Λ . ... 35, and if you get up to 2% metallic

U, 6 to 1.1 J ₀ bihcium, magnesium incorporated into the core, then becomes a

A ^ u- ^S λ'tJ, ° i ???? - α Improvement of the toughness ensured.

Λ w Δ / ^{/ e} molybdenum The important influence of the weld metal deoxy-

3.5 to 16 / β iron. äa & on both the porosity and the notch

Core electrodes according to the invention, in which 0.3 40 impact resistance has long been known, and the up to 1% magnesium, 3.5 to 6% of alkali or earth welding technology has dealt intensively with it. According to alkali metal fluoride, 0.6 to 1.3% of the alkaline earth metal - the principles of welding, magnesium must be classified as a carbonate and 9 to 18% of a mixture of strong deoxidizing metal present, but are that, in percent by weight of the electrode, the following has been found that it also has an influence on the impact composition: 45 strength has an influence, which is actually extremely common. Such an effect is caused by other nt u- ^S 1 * 0 / rr ^aum 'deoxidation metals, such as aluminum and η -> £ * Ifijf irf ??; Titanium, with which it classified in the same group 0.2 to 0.7% molybdenum, was not produced no uic η το / π ,, .-, wurue, iuchi produced.

1 W 1U1 M-tT ' ⁵ ° ^{The best way to} exploit the previously un-

^S i «o / κ α knew and unique properties and the

0.4 until 1.1 · /. Silicon, 0.5 until 1.6% Manganese, 0.2 until OJ ⁰ Io Molybdenum, 0.2 until 0.7% Chrome, 1 until 2.2% Nickel, 5 until 15 · /. Iron and 0.03 until 0.30% Carbon. According to the invention Soul electrodes in which 0.3

<Ki «o / κ α

η _M i? ^S η ™ «ι ^ ^1S t? «Easiest and most reliable way to use 0.03-0.30% carbon. metallic magnesium according to the invention. Considerable improvements in the weld seam are achieved with core electrodes of the specified type metal toughness when starting up to 2% 55, which is already known in welding technology for its metallic magnesium in the core materials of a general welding behavior are. Although clean balanced electrode are included. The welding of such electrodes is satisfactory and the addition of metallic magnesium is especially effective for composite electrode types, required by the AWS test standard, notched impact strength of 2.8 mkg, but they give the best toughness values, which are considerable according to 60 efforts by the state of the art using a change in the type and amount of conventional materials and while maintaining healthy deoxidation metal content. Which of the welding principles are available. Effectiveness of metallic magnesium can These types include inert gas electrodes with be shown by omitting the entire fluoride-based deoxy slag system and lime / fluoride dation metal from the core, then the base and inert gas and submerged arc - a typical amount of magnesium powder, such as B. electrodes of the types with low flux - 0.6% of the electrode weight, is added and content and without flux content. The incorporation of the deoxidation metal content in stages

309630/325

is restored, with notched impact tests are made. When restoring the deoxidation metal content, it is best to use moderately strong elements such as B. to use manganese and silicon and other very strong metals, such as aluminum and titanium, which easily give an overly strong effect, to avoid or to use only to a small extent. If one magnesium used as a strong deoxidizer together with other less violent Desoxydationsmetallen, the hitherto regarded as the boundary notched impact strength values are broken and often improvements are up to 100 ° / ₀ achieved.

True, the exact mechanism by which the magnesium moves the weld towards a greater impact strength improved, not known, but it is believed that the strong affinity of

10

Magnesium for oxygen at least partially for this responsible for. It was not possible to determine exactly whether magnesium was actually oxygen content of the weld metal decreases or whether the magnesium is bringing in the oxygen in the weld a less harmful form than other deoxidizers, which do not have the impact strength in the Ways magnesium can improve binds. However, it has been found that magnesium is the present Much improved soul electrodes. It is true that any metal that deoxidizes iron should be used at some point have been used and tried in tubular electrodes, but the special one Effect that small amounts of magnesium have on the notch

IS can exert impact resistance, has so far been not recognized and not yet used in welding technology.

Table I Examples of the beneficial influence of magnesium

Debris gas electrode

IA I IB Shielding gas electrode UA I HB

Submerged arc electrode HIA j HIB j HIC | HID

Electrode diameter [cm]

2.78 I 2.78 I 2.38 | 2.38 | 3.17 | 3.17 | 3.17 | 3.17 Electrode composition [percent by weight]

Shielding gas electrode IVA I IVB

1.59 I 1.59

Magnesium metal 0 Kalhun silicofluoride 0.4 Potassium titanate 0.4 Calcium carbonate 0.8 Calcium fluoride 4.0 Iron powder 14.4 Ferromanganese (80% Mn) 1.3 Ferrosilicon (50 · /. Si) 1.8 Ferromolybdenum (60 · /. Mo) 0.9 Ferrochrome (70% Cr) Manganese powder Nickel powder Carbon steel shell rest Typical welding conditions Voltage, volts 27 Electricity, amps 450 Running speeds, cm / min. 55.9 Protective medium CO, <§>

1.13m * / h

Notched impact strength (Schtagarbeh) the weld seam in mkg at:

Room temperature 9.65

-12 ^ ° C

-28.9 ° C 3.45

-40.0 ⁰ C

-51.1 ° C

-73.3 "C

-101.1 ⁰ C

Table I shows the advantageous effect on the impact strength Voq welds that vonMagnesiummetall automatic by adding to Seelenelektrodenfür welding is achieved. The electrodes III A, III B, HIC and III D form a group of submerged powder arc electrodes with a low flux content. The first is a base composition to which increasing amounts of magnesium have been added in three stages. B. based on calcium precipitate, which was used in the comparative experiments,

0.8 0 0.6 0.4 0.4 0.4 0.4 0.2 0.8 0.8 0.8 4.0 4.0 4.7 13.6 7.7 7.7 U 2.1 1.0 1.8 1.5 1.4 0.9 0.7 0.7 - 0.6 0.6 - 0.6 - 2.0 2.0 rest rest rest 27 26th 26th 450 400 400 55.9 55.9 55.9 CO, @ CO, @ CQ _t @ 1.13m '/ h 1.13m »/ h 1.13m * / h 7.32 11.8 10.2 6.64 3.78 7.03 - 3.40 4.01 - 2.10 1.80

0 0.2 0.7 2.0 2.0 2.0 17.0 17.0 17.0 1.6 1.4. 0.9 0.6 0.6 0.6 0.9 0.9 0.9 0.9 0.9 0.9 rest rest rest 28 28 28 450 450 450 55.9 55.9 55.9 Flow Flow Flow medium medium medium

0.9

2.0 17.0 0.8 0.6 0.9

0.9 remainder

28 450 55.9 flux

based on calcium silicate

8.50

2.39 1.77 0.48

9 ^ 5

3.87 3.60 1.11

11.0

5.30 4.18 1.38

11.0

5.66 3.63 1.66

0.2

9.2 1.4 13 0.7 0.6

1.7 rest

20 200 25.4

75%

argon

CO, @

0.7 m * / h

7.51

4.85 3.47

1.7 rest

20 200 25.4

argon

+ 25%

CO, @

0.7 m »/ h

manufactured. When producing a weld seam under the specified conditions, all these electrodes give a notched impact strength (impact work) of 2.8 mkg at -28.9 ° C, but the basic composition ΠΙΑ does not give this value at -51.1 ° C. Magnesium additions of 0.2, 0.7 and 0.9 'I _0, however, result in notched impact strength values of 3.87, 5.30 or 5.66 mkg at this temperature. The conventional value of 2.8 mkg was exceeded even by the slightest addition of magnesium of only 0.2% at -73.3 ° C.

Set the electrode pairs IA, IB and HA, ΠΒ a tubular shielding gas electrode on the base

Lime / fluoride represents the core composition is selected to perform a number of functions, such as chopping. Such Electrodes work under a carbon dioxide protective gas with a spray or ball transition. Compared with the first of each pair, the second shows a strong improvement in notched impact strength, which is achieved by adding magnesium to the electrode. The one made with IB Weld seam shows values almost twice as high as that of IA at -28.9 ° C. The notched impact strength of HB is also almost twice that of IIA and is increased by the Magnesium addition achieved, although in this case the demonstration was achieved through small adjustments of the others Components is a bit washed out.

The core electrodes IVA and IVB of Table I are given as further examples according to the invention, which represent a type of flux-free protective gas electrode which are produced for welding under an ao argon and carbon dioxide atmosphere. The electrode IVB with 0.6 ° / ₀ added magnesium has at least a 30% higher impact strength than the electrode IVA.

The good influence on the notched impact strength of »5 weld seams, which the addition of magnesium metal to the core material has, is clearly shown by the numbers in Table I. Improvements of up to 100% have been achieved with regard to the notched impact strength of weld seams when using core electrodes that contain magnesium metal in the electrode core. This beneficial effect has not yet been recognized. If the amount of magnesium in the core composition is increased above the concentration given in Table I, then the impact strength does not increase proportionally. If more than 3 * / · magnesium metal is added, the performance of the electrode tends to be deteriorated and an advantage is not obtained. The splash when welding increases, and the arc becomes loud and dances. Therefore, it is preferred to limit the amount of magnesium to 2 * _{19 of} the electrodes.

For economic reasons, the preferred electrode shapes are approximately 0.2 to 2% magnesium used in the electrode.

For the purpose of further explanation there are four further examples of tubular composite elements in the following table Electrodes indicated in which metallic magnesium is used in the core.

Examples 1 and 4 relate to types with a lime / fluoride base, which are used for gas-shielded carbon dioxide welding are made. Examples 2 and 3 are both flux-free types; Example 2 is suitable for welding under carbon dioxide protection and example 3 for submerged arc welding. In each case, an addition of magnesium was used to make substantial improvements in the To obtain weld metal toughness, which goes well beyond the toughness offered by the current one A.W.S. test standard for core electrodes is required.

Table II

More examples of the beneficial effects of magnesium

Magnesium metal

Potassium titanate

Potassium sificofluoride

Calcium carbonate

Calcium fluoride

Iron powder

Ferromanganese (80% Mn)
Ferrosilicon (50% Si) ...
Ferromolybdenum (60% Mo)
Ferrochrome (70% Cr) ...

Manganese powder

Nickel powder

Carbon steel shell

1 I 2 I 3 I 4 Electrode diameter, cm 1.59 I 1.59 I 3.17 | 2.38

Electrode composition, weight percent

0.4 0.6 0.9 0.4 - - 0.4 - - 0.8 - - 4.0 - - 9.9 8.8 19.0 0.8 1.4 0.8 1.6 1.3 0.6 0.9 0.7 0.9 - 0.6 - 1.7 0.9 rest rest rest

0.7 0.6 1.5 2.0 remainder

Claims (12)

Patent claims: 1. Core electrode for fully and semi-automatic arc welding to achieve a non-austenitic mild steel or alloy steel weld seam with improved notched impact strength, consisting of a tubular steel shell and a core, thereby identifying draws that the core in percent by weight the electrode made of 0.3 to 1% magnesium and 9 to 18% of a mixture 0.4 until 0.9 · /. Silicon, 0.6 until 1.6 /, Manganese, 0.3 until 0.6 /, Molybdenum, 0.2 until 0.7 · /. Chrome, 1 until 2.2% Nickel, 5.5 until 14 · /. Iron and 0.03 until 0.10 · /. carbon consists. 2. Electrode according to claim 1, characterized in that the core consists of 0.3 to 1 ^e / ₀ magnesium and 18 to 26% of a mixture »5- until to 0.5% 0.10% Silicon, 0.4 until 1.2% Manganese, 0.3 until 0.8% Molybdenum, 0.6 until 1.3% Nickel, 15.5 up to 24.5% Iron and 0.03 until carbon 30th consists. 3. Electrode according to claim 1 or 2, characterized in that the core is still up to 1.5% an alkali metal titanate, an alkali metal silicofluoride and / or an alkali metal aluminate as an arc stabilizer. 4. Electrode according to claim 3, characterized in that 0.2 to 2% magnesium, up to 1.3% of the arc stabilizer and 4 to 24% of the mixture are present. 5. Electrode according to claim 3 or 4, characterized in that 0.3 to 1% magnesium, 0.1 to 0.4% of the sheet stabilizer and 9 to 17% of a mixture 0.4 to 0.9% silicon, 0.6 to 1.6% manganese, 0.2 to 0.6% molybdenum, ⁵ ^ 0.2 to 0.7% chromium, 1 to 2.2% nickel, 5 to 13% iron and 0.03 to 0.10% carbon are present. 6. Electrode according to one of the preceding claims, characterized in that it still Contains up to 9% of an alkali or alkaline earth metal fluoride. 7. Electrode according to claim 6, characterized in that 0.2 to 2% magnesium, 0.7 to 3% of the alkali or alkaline earth metal fluoride and 12 to 35% of the mixture are present. 8. Electrode according to claim 6 or 7, characterized in that 0.3 to 1% magnesium, 1.4 to 2.3% of the alkali or alkaline earth metal fluoride and 17 to 23% of a mixture 55 60 up to 0.5% 0.4 to 1.2% 0.3 to 0.8% 0.6 to 1.3% 14.5 to 22% 0.03 to 0.10% Silicon, Manganese, Molybdenum, Nickel, Iron and carbon are present. 9. Electrode according to one of the preceding claims, characterized in that 0.3 to 1% magnesium, 0.1 to 1.1% of the arc stabilizer, 3.5 to 6% of the alkali or alkaline earth metal fluoride, 0.6 to 1.3% of an alkaline earth metal carbonate and 9 to 18% of a mixture 0.6 to 1.1% silicon, 0.5 to 1.6% manganese, 0.4 to 0.7% molybdenum, 5.5 to 16% iron and 0.03 to 0.30% carbon are present. 10. Electrode according to one of the preceding claims, characterized in that 0.3 to 1% magnesium, 0.1 to 1.1% of the arc stabilizer, 3.5 to 6% of the alkali metal or alkaline earth metal fluoride, 0.6 to 1.3% of the alkaline earth metal carbonate, and 9 to 18% of a mixture out 0.4 until 1.1% Silicon, 0.5 until 1.6% Manganese, 0.2 until 0.7% Molybdenum, 0.2 until 0.7% Chrome, 1 until 2.2% Nickel, 5 until 15% Iron and 0.03 until 0.30% carbon are present. 11. Electrode according to one of the preceding claims, characterized in that 0.3 to 1% magnesium, 3.5 to 6% of the alkali metal or alkaline earth metal fluoride, 0.6 to 1.3% of the Alkaline earth metal carbonate and 9 to 18% of a mixture 0.6 to 1.1% silicon, 0.5 to 1.6% manganese, 0.4 to 0.7% molybdenum and 5.5 to 16% iron are present. 12. Electrode according to one of the preceding claims, characterized in that 0.3 to 1% magnesium, 3.5 to 6% of the alkali metal or alkaline earth metal fluoride, 0.6 to 1.3% of the Alkaline earth metal carbonate and 9 to 18% of a mixture 0.4 to 0.5 to 0.2 to 0.2 to 1 to 5 to 15% 0.03 to 0.30% are present. 14% 1.6% 0.7% 0.7% 2.2% Silicon, Manganese, Molybdenum, Chrome, Nickel, Iron and carbon