It is possible that the Wheel of History is welded with a tungsten electrode.

Relevance

The tungsten electrode refers to a non-fusing electrode. Tungsten electrodes are characterized by hardness even under high heat, wear resistance, the minimum coefficient of thermal expansion among metals. Such electrodes have significant resistance to thermal creep, good thermal conductivity, and a very high modulus of elasticity. Demand of modern industry for such products has been constant for many years.

Production

Technological plasticity of W is low at ordinary temperatures, so the electrode is produced by hot working under pressure. First, a billet, the so-called stabile, is made by powder metallurgy. Then it is heated and rolled in a rotary forging machine to Ø 2 - 3 mm... This rod is usually supplied in straight sections.

Welding procedure

Tungsten electrode - thin rod may or may not have a special coating. The coating includes components: slag- and gas-forming, stabilizing, alloying, deoxidizing. Arc welding produces a permanent electrical discharge in an ionized atmosphere - a volt arc with t° > 1000 °C. Carbon and tungsten electrodes are non-consumable. Therefore, welding requires a filler material - a welding wire, which together with the molten metal of the workpiece forms a welding seam. Electrode coating stabilizes the combustion of the arc, protects the molten weld from oxidation by atmospheric gases and gives it the necessary properties. Acid, basic, rutile or cellulose coating is used.

Optimization of welding procedure

Tungsten electrode (EHF grade) with zirconium additive has improved ignition performance and more stable arc. Thorium additive (to the EVT-15 electrode) also optimizes the arc ignition and lengthens the lifetime of the electrode. When welding non-ferrous alloys it is better to use tungsten electrodes with Zr additive, for high-alloy steels - with thorium additive. The weld is very strong, even between parts of different compositions. Tungsten electrodes with yttrium additive (EVI-1, EVI-2, EVI-3) can weld parts in DC or AC current. In alternating current, the welding arc can be powered by single-phase and 3-phase. Welding under argon protection (increases the quality of the weld even more. Argon protects the work area from atmospheric gas mixture (_N2, _O2, _CO2). This not only strengthens the weld, but also slows down combustion of the electrode. Thus the electrodes last longer.

Domestic brands

Length of electrodes is 1000 mm, Ø: 1,6; 2; 3; 4 mm. Surface of electrodes polished, smooth, without cracks, chips, burrs, traces of grease. By order tungsten electrodes are made of any parameters. V.L., EVL-2 grades are suitable for all alloy grades, used at direct or alternating current. VL, VA, SVI tungsten electrodes are characterized by high thermostability. Lanthanum stabilized electrodes have easy initial ignition and re-ignition of the arc, stable combustion without a tendency to burn through. Compared with pure tungsten, alloying with 2% _{La2 O3} increases the maximum current and carrying capacity of the electrode by 50%. Such electrodes are more durable than thorium or cerium electrodes, do not burn out so quickly and almost do not introduce tungsten into the weld. Uniform distribution of _{La2 O3} helps to keep the original sharpening of the electrode. SVI-1 / EVI-1 electrodes reliably weld fragments of copper alloys, titanium, stainless and low-alloy steels at DC direct polarity (DC). Yttrium electrode is the most resistant. Yttrium oxides up to 2,2%, stabilize the cathode spot at the end of the electrode making the arc very stable regardless of the current used. EVL-2 and EVF electrodes (TU 48-19-527-91) are used for arc welding, cutting, surfacing and cladding under inert gases.

Percentages

Electrode brand	Tungsten	Lanthanum oxide	Impurity Al, Fe, Si, Ca, to
EVF	over 99.9	--	0.1
EVL-2	97,9 - 98,3	1.6 - 2	0.1

Electrode parameters

Electrode brand	Diameter Ø, mm	Tolerance	Length, mm	Tolerance
EVF	1, 1.6, 2, 2.5, 3, 4	±0.1	75; 150; 200	±2.0
EVF	5, 6, 8	±0.2	75; 150; 200	±2.0
EVL-2	1, 1.6, 2, 2.5, 3, 4	±0.1	75; 150; 200	±2.0
EVL-2	5, 6	±0.2	75; 150; 200	±2.0

Quality

Supplies

The electrode must have an even surface without cracks, burrs, chips, traces of grease , etc. The surface of the rod Ø1; 1.6; 2; 2.5 mm is etched. The surface is allowed to have discoloration colors, minor defects, traces of broaches within the permissible diameter deviations. Electrodes are cut at the ends, chipping up to 1 mm is permissible. Deviation from straightness - up to ¼% of the electrode length. EVL-2 electrodes are marked with black oil paint.

Imported marks

WP, WZ8, WL-20, WC-20, WT-20, WY-20 tungsten electrodes are the most popular for arc welding in inert atmosphere. Such electrodes are used for TIG-welding Tungsten Insert Gas (ADS, GTA, WIG) - automatic, semi-automatic, manual arc welding under protection of the following mixtures: _Ar2 + _He2, _Ar2 + _O2, _Ar2 + _CO2.

Table 1. electrodes in pouches for argon-arc welding

Tungsten electrodes l=175 mm in cases of 10 pieces

grade (color code)	diameter in mm	amount in 1 kg	additives	Note
WC-20 (gray)	1.6	151	1.8-2.2% (cerium dioxide)	Stainless, acid- and heat-resistant steels and metals (molybdenum, niobium, nickel, tantalum, titanium and their alloys, copper, bronze, silicon bronze.
WC-20 (gray)	2	96	1.8-2.2% (cerium dioxide)	Stainless, acid- and heat-resistant steels and metals (molybdenum, niobium, nickel, tantalum, titanium and their alloys, copper, bronze, silicon bronze.
WC-20 (gray)	2.4	66	1.8-2.2% (cerium dioxide)	Stainless, acid- and heat-resistant steels and metals (molybdenum, niobium, nickel, tantalum, titanium and their alloys, copper, bronze, silicon bronze.
WC-20 (gray)	3	42	1.8-2.2% (cerium dioxide)	Stainless, acid- and heat-resistant steels and metals (molybdenum, niobium, nickel, tantalum, titanium and their alloys, copper, bronze, silicon bronze.
WC-20 (gray)	3.2	37	1.8-2.2% (cerium dioxide)	Stainless, acid- and heat-resistant steels and metals (molybdenum, niobium, nickel, tantalum, titanium and their alloys, copper, bronze, silicon bronze.
WC-20 (gray)	4	24	1.8-2.2% (cerium dioxide)	Stainless, acid- and heat-resistant steels and metals (molybdenum, niobium, nickel, tantalum, titanium and their alloys, copper, bronze, silicon bronze.
WL-20 (blue)	1.6	151	1.8-2.2% (lanthanum dioxide)	Joining of thin sheets, high-alloy steel, surfacing on molds, valves, cutting of aluminum, bronze, copper and high-alloy steels.
WL-20 (blue)	2.0	96	1.8-2.2% (lanthanum dioxide)	Thin plate joining, high-alloy steel, surfacing on molds, valves, cutting of aluminum, bronze, copper and high-alloy steels.
WL-20 (blue)	2.4	66	1.8-2.2% (lanthanum dioxide)	Thin plate joining, high-alloy steel, surfacing on molds, valves, cutting aluminum, bronze, copper and high-alloy steels.
WL-20 (blue)	3	42	1.8-2.2% (lanthanum dioxide)	Thin plate joining, high-alloy steel, surfacing on molds, valves, cutting aluminum, bronze, copper and high-alloy steels.
WL-20 (blue)	3.2	37	1.8-2.2% (lanthanum dioxide)	Thin plate joining, high-alloy steel, surfacing on molds, valves, cutting aluminum, bronze, copper and high-alloy steels.
WL-20 (blue)	4	24	1.8-2.2% (lanthanum dioxide)	Thin plate joining, high-alloy steel, surfacing on molds, valves, cutting aluminum, bronze, copper and high-alloy steels.
WT-20 (red)	1.6	151	1.8-2.2% (thorium dioxide)	Durable. Constant current for welding. Easy arc ignition Shape stability at high currents. Angle of sharpening can be changed.
WT-20 (red)	2	96	1.8-2.2% (thorium dioxide)	Durable. Constant current for welding. Easy arc ignition Shape stability at high currents. Angle of sharpening can be changed.
WT-20 (red)	2.4	66	1.8-2.2% (thorium dioxide)	Durable. Constant current for welding. Easy arc ignition Shape stability at high currents. Angle of sharpening can be changed.
WT-20 (red)	3.0	42	1.8-2.2% (thorium dioxide)	Durable. Constant current for welding. Easy arc ignition Shape stability at high currents. Angle of sharpening can be changed.
WT-20 (red)	3.2	37	1.8-2.2% (thorium dioxide)	Durable. Constant current for welding. Easy arc ignition Shape stability at high currents. Angle of sharpening can be changed.
WT-20 (red)	4	24	1.8-2.2% (thorium dioxide)	Durable. Constant current for welding. Easy arc ignition Shape stability at high currents. Angle of sharpening can be varied.
WZ8 (white)	1.6	151	0.8% (zirconia)	Similar to pure tungsten. AC welding of critical joints. Easy ignition and arc stability.
WZ8 (white).	2	96	0.8% (zirconia).	Similar to pure tungsten. AC welding of critical joints. Easy ignition and arc stability.
WZ8 (white).	2.4	66	0.8% (zirconia).	Similar to pure tungsten. AC welding of critical joints. Easy ignition and arc stability.
WZ8 (white).	3	42	0.8% (zirconia).	Similar to pure tungsten. AC welding of critical joints. Easy ignition and arc stability.
WZ8 (white).	3.2	37	0.8% (zirconia).	Similar to pure tungsten. AC welding of critical joints. Easy ignition and arc stability.
WZ8 (white).	4	24	0.8% (zirconia).	Similar to pure tungsten. AC welding of critical joints. Easy ignition and arc stability.
WP (green).	2	96	Pure W without alloying additives.	AC welding of Al, Mg and their alloys. Satisfactory arc ignition capability. Long enough service life.
WP (green)	2.4	66	Pure W without alloying additives.	AC welding of Al, Mg and their alloys. Satisfactory arc ignition capability. Sufficient lifetime.
WP (green)	3	42	Pure W without alloying additives.	AC welding of Al, Mg and their alloys. Satisfactory arc ignition capability. Long enough service life.
WP (green)	3.2	37	Pure W without alloying additives.	AC welding of Al, Mg and their alloys. Satisfactory arc ignition capability. Sufficient lifetime.
WP (green)	4	24	Pure W without alloying additives.	AC welding of Al, Mg and their alloys. Satisfactory arc ignition capability. Long enough service life.
WP (green)	5	15	Pure W without alloying additives.	AC welding of Al, Mg and their alloys. Satisfactory arc ignition capability. Long enough service life.
WY-20 (dark blue)	1.6	151	1.8-2.2% (yttrium oxide)	DC welding of the most demanding joints. Easy arc ignition, long service life.
WY-20 (dark blue)	2	96	1.8-2.2% (yttrium oxide)	DC welding of the most demanding joints. Easy arc ignition, long service life.
WY-20 (dark blue).	2.4	66	1.8-2.2% (yttrium oxide)	DC welding of the most demanding joints. Easy arc ignition, long service life.
WY-20 (dark blue).	3	42	1.8-2.2% (yttrium oxide)	DC welding of the most demanding joints. Easy arc ignition, long service life.
WY-20 (dark blue).	3.2	37	1.8-2.2% (yttrium oxide)	DC welding of the most demanding joints. Easy arc ignition, long service life.
WY-20 (dark blue).	4	24	1.8-2.2% (yttrium oxide)	DC welding of the most demanding joints. Easy arc ignition, long service life.

With WL-20 (W + 2.2% _{La2 O3}) easy arc ignition and re-ignition, stable arc without burning-through tendency. The admixture of _{La2 O3} increases the carrying capacity of the electrode by 1.5 times and the maximum current when welding with alternating current. Lanthanum electrodes as compared to WC-20 and WT-20 (with cerium and thorium admixture) are more durable, with less wear of the working end and minimal weld contamination. Uniform distribution of _{La2 O3} in the electrode, keeps its original sharpening for a long time at any welding current. Alternating sinusoidal current requires a spherical sharpening of the working end of the electrode. WC-20 The admixture of up to 2.2% of CeO oxide, the most common non-radioactive rare-earth element, to tungsten facilitates the initial arc start-up, improves electrode emission and increases the maximum welding current. These electrodes can be welded at any current characteristic. WC-20 has a more stable arc even at low voltages. WC-20 is used for orbital welding of pipes, thin sheet steel and pipelines. It is considered a disadvantage that when welding with high current values, the CeO oxide concentrates at the working end of the electrode.

Table 2. Optimal current values for tungsten electrodes in argon arc welding

electrode Ø, mm	Forward polarity	Reverse polarity	Positive and negative half-wave are equal	Negative half-wave is greater than positive half-wave
4	400 - 500	40 - 55	200 - 320	300 - 400
3.2	250 - 400	25 - 40	160 - 250	225 - 325
3	220 - 350	20 - 35	140 - 230	200 - 300
2.4	150 - 250	15 - 30	100 - 180	140 - 235
2	100 - 200	12 - 25	70 - 130	80 - 160
1.6	70 - 150	10 - 20	60 - 120	70 - 150

Buy at a bargain price

Evek GmbH offers electrodes for wholesale and retail buyers. On our site you will find all the necessary information. We are waiting for your orders.

It is possible that the Wheel of History is welded with a tungsten electrode.

Relevance

The tungsten electrode refers to a non-fusing electrode. Tungsten electrodes are characterized by hardness even under high heat, wear resistance, the minimum coefficient of thermal expansion among metals. These electrodes have significant resistance to thermal creep, good thermal conductivity, and a very high modulus of elasticity. Demand of modern industry for such products has been constant for many years.

Production

Technological plasticity of W is low at ordinary temperatures, so the electrode is produced by hot working under pressure. First, a billet, the so-called stabile, is made by powder metallurgy. Then it is heated and rolled in a rotary forging machine to Ø 2 - 3 mm... This rod is usually supplied in straight sections.

Welding procedure

Tungsten electrode - thin rod may or may not have a special coating. The coating includes components: slag- and gas-forming, stabilizing, alloying, deoxidizing. Arc welding produces a permanent electrical discharge in an ionized atmosphere - a volt arc with t° > 1000 °C. Carbon and tungsten electrodes are non-consumable. Therefore, welding requires a filler material - a welding wire, which together with the molten metal of the workpiece forms a welding seam. Electrode coating stabilizes the combustion of the arc, protects the molten weld from oxidation by atmospheric gases and gives it the necessary properties. Acid, basic, rutile or cellulose coating is used.

Optimization of welding procedure

Tungsten electrode (EHF grade) with zirconium additive has improved ignition performance and more stable arc. Thorium additive (to the EVT-15 electrode) also optimizes the arc ignition and lengthens the lifetime of the electrode. When welding non-ferrous alloys it is better to use tungsten electrodes with Zr additive, for high-alloy steels - with thorium additive. The weld is very strong, even between parts of different compositions. Tungsten electrodes with yttrium additive (EVI-1, EVI-2, EVI-3) can weld parts in DC or AC current. In alternating current, the welding arc can be powered by single-phase and 3-phase. Welding under argon protection (increases the quality of the weld even more. Argon protects the work area from atmospheric gas mixture (_N2, _O2, _CO2). This not only strengthens the weld, but also slows down combustion of the electrode. Thus the electrodes last longer.

Domestic brands

Length of electrodes is 1000 mm, Ø: 1,6; 2; 3; 4 mm. Surface of electrodes polished, smooth, without cracks, chips, burrs, traces of grease. By order tungsten electrodes are made of any parameters. V.L., EVL-2 grades are suitable for all alloy grades, used at direct or alternating current. VL, VA, SVI tungsten electrodes are characterized by high thermostability. Lanthanum stabilized electrodes have easy initial ignition and re-ignition of the arc, stable combustion without a tendency to burn through. Compared with pure tungsten, alloying with 2% _{La2 O3} increases the maximum current and carrying capacity of the electrode by 50%. Such electrodes are more durable than thorium or cerium electrodes, do not burn out so quickly and almost do not introduce tungsten into the weld. Uniform distribution of _{La2 O3} helps to keep the original sharpening of the electrode. SVI-1 / EVI-1 electrodes reliably weld fragments of copper alloys, titanium, stainless and low-alloy steels at DC direct polarity (DC). Yttrium electrode is the most resistant. Yttrium oxides up to 2,2%, stabilize the cathode spot at the end of the electrode making the arc very stable regardless of the current used. EVL-2 and EVF electrodes (TU 48-19-527-91) are used for arc welding, cutting, surfacing and cladding under inert gases.

Percentages

Electrode brand	Tungsten	Lanthanum oxide	Impurity Al, Fe, Si, Ca, to
EVF	over 99.9	--	0.1
EVL-2	97,9 - 98,3	1.6 - 2	0.1

Electrode parameters

Electrode brand	Diameter Ø, mm	Tolerance	Length, mm	Tolerance
EVF	1, 1.6, 2, 2.5, 3, 4	±0.1	75; 150; 200	±2.0
EVF	5, 6, 8	±0.2	75; 150; 200	±2.0
EVL-2	1, 1.6, 2, 2.5, 3, 4	±0.1	75; 150; 200	±2.0
EVL-2	5, 6	±0.2	75; 150; 200	±2.0

Quality

Supplies

The electrode must have an even surface without cracks, burrs, chips, traces of grease , etc. The surface of the rod Ø1; 1.6; 2; 2.5 mm is etched. The surface is allowed to have discoloration colors, minor defects, traces of broaches within the permissible diameter deviations. Electrodes are cut at the ends, chipping up to 1 mm is permissible. Deviation from straightness - up to ¼% of the electrode length. EVL-2 electrodes are marked with black oil paint.

Imported marks

WP, WZ8, WL-20, WC-20, WT-20, WY-20 tungsten electrodes are the most popular for arc welding in inert atmosphere. Such electrodes are used for TIG-welding Tungsten Insert Gas (ADS, GTA, WIG) - automatic, semi-automatic, manual arc welding under protection of the following mixtures: _Ar2 + _He2, _Ar2 + _O2, _Ar2 + _CO2.

Table 1. pencil case electrodes for argon-arc welding

Tungsten electrodes l=175 mm in cases of 10 pieces

grade (color code)	diameter in mm	amount in 1 kg	additives	Note
WC-20 (gray)	1.6	151	1.8-2.2% (cerium dioxide)	Stainless, acid- and heat-resistant steels and metals (molybdenum, niobium, nickel, tantalum, titanium and their alloys, copper, bronze, silicon bronze.
WC-20 (gray)	2	96	1.8-2.2% (cerium dioxide)	Stainless, acid- and heat-resistant steels and metals (molybdenum, niobium, nickel, tantalum, titanium and their alloys, copper, bronze, silicon bronze.
WC-20 (gray)	2.4	66	1.8-2.2% (cerium dioxide)	Stainless, acid- and heat-resistant steels and metals (molybdenum, niobium, nickel, tantalum, titanium and their alloys, copper, bronze, silicon bronze.
WC-20 (gray)	3	42	1.8-2.2% (cerium dioxide)	Stainless, acid- and heat-resistant steels and metals (molybdenum, niobium, nickel, tantalum, titanium and their alloys, copper, bronze, silicon bronze.
WC-20 (gray)	3.2	37	1.8-2.2% (cerium dioxide)	Stainless, acid- and heat-resistant steels and metals (molybdenum, niobium, nickel, tantalum, titanium and their alloys, copper, bronze, silicon bronze.
WC-20 (gray)	4	24	1.8-2.2% (cerium dioxide)	Stainless, acid- and heat-resistant steels and metals (molybdenum, niobium, nickel, tantalum, titanium and their alloys, copper, bronze, silicon bronze.
WL-20 (blue)	1.6	151	1.8-2.2% (lanthanum dioxide)	Joining of thin sheets, high-alloy steel, surfacing on molds, valves, cutting of aluminum, bronze, copper and high-alloy steels.
WL-20 (blue)	2.0	96	1.8-2.2% (lanthanum dioxide)	Thin plate joining, high-alloy steel, surfacing on molds, valves, cutting of aluminum, bronze, copper and high-alloy steels.
WL-20 (blue)	2.4	66	1.8-2.2% (lanthanum dioxide)	Thin plate joining, high-alloy steel, surfacing on molds, valves, cutting aluminum, bronze, copper and high-alloy steels.
WL-20 (blue)	3	42	1.8-2.2% (lanthanum dioxide)	Thin plate joining, high-alloy steel, surfacing on molds, valves, cutting aluminum, bronze, copper and high-alloy steels.
WL-20 (blue)	3.2	37	1.8-2.2% (lanthanum dioxide)	Thin plate joining, high-alloy steel, surfacing on molds, valves, cutting aluminum, bronze, copper and high-alloy steels.
WL-20 (blue)	4	24	1.8-2.2% (lanthanum dioxide)	Thin plate joining, high-alloy steel, surfacing on molds, valves, cutting aluminum, bronze, copper and high-alloy steels.
WT-20 (red)	1.6	151	1.8-2.2% (thorium dioxide)	Durable. Constant current for welding. Easy arc ignition Shape stability at high currents. Angle of sharpening can be changed.
WT-20 (red)	2	96	1.8-2.2% (thorium dioxide)	Durable. Constant current for welding. Easy arc ignition Shape stability at high currents. Angle of sharpening can be changed.
WT-20 (red)	2.4	66	1.8-2.2% (thorium dioxide)	Durable. Constant current for welding. Easy arc ignition Shape stability at high currents. Angle of sharpening can be changed.
WT-20 (red)	3.0	42	1.8-2.2% (thorium dioxide)	Durable. Constant current for welding. Easy arc ignition Shape stability at high currents. Angle of sharpening can be changed.
WT-20 (red)	3.2	37	1.8-2.2% (thorium dioxide)	Durable. Constant current for welding. Easy arc ignition Shape stability at high currents. Angle of sharpening can be changed.
WT-20 (red)	4	24	1.8-2.2% (thorium dioxide)	Durable. Constant current for welding. Easy arc ignition Shape stability at high currents. Angle of sharpening can be varied.
WZ8 (white)	1.6	151	0.8% (zirconia)	Similar to pure tungsten. AC welding of critical joints. Easy ignition and arc stability.
WZ8 (white).	2	96	0.8% (zirconia).	Similar to pure tungsten. AC welding of critical joints. Easy ignition and arc stability.
WZ8 (white).	2.4	66	0.8% (zirconia).	Similar to pure tungsten. AC welding of critical joints. Easy ignition and arc stability.
WZ8 (white).	3	42	0.8% (zirconia).	Similar to pure tungsten. AC welding of critical joints. Easy ignition and arc stability.
WZ8 (white).	3.2	37	0.8% (zirconia).	Similar to pure tungsten. AC welding of critical joints. Easy ignition and arc stability.
WZ8 (white).	4	24	0.8% (zirconia).	Similar to pure tungsten. AC welding of critical joints. Easy ignition and arc stability.
WP (green).	2	96	Pure W without alloying additives.	AC welding of Al, Mg and their alloys. Satisfactory arc ignition capability. Long enough service life.
WP (green)	2.4	66	Pure W without alloying additives.	AC welding of Al, Mg and their alloys. Satisfactory arc ignition capability. Sufficient lifetime.
WP (green)	3	42	Pure W without alloying additives.	AC welding of Al, Mg and their alloys. Satisfactory arc ignition capability. Long enough service life.
WP (green)	3.2	37	Pure W without alloying additives.	AC welding of Al, Mg and their alloys. Satisfactory arc ignition capability. Sufficient lifetime.
WP (green)	4	24	Pure W without alloying additives.	AC welding of Al, Mg and their alloys. Satisfactory arc ignition capability. Long enough service life.
WP (green)	5	15	Pure W without alloying additives.	AC welding of Al, Mg and their alloys. Satisfactory arc ignition capability. Long enough service life.
WY-20 (dark blue)	1.6	151	1.8-2.2% (yttrium oxide)	DC welding of the most demanding joints. Easy arc ignition, long service life.
WY-20 (dark blue)	2	96	1.8-2.2% (yttrium oxide)	DC welding of the most demanding joints. Easy arc ignition, long service life.
WY-20 (dark blue).	2.4	66	1.8-2.2% (yttrium oxide)	DC welding of the most demanding joints. Easy arc ignition, long service life.
WY-20 (dark blue).	3	42	1.8-2.2% (yttrium oxide)	DC welding of the most demanding joints. Easy arc ignition, long service life.
WY-20 (dark blue).	3.2	37	1.8-2.2% (yttrium oxide)	DC welding of the most demanding joints. Easy arc ignition, long service life.
WY-20 (dark blue).	4	24	1.8-2.2% (yttrium oxide)	DC welding of the most demanding joints. Easy arc ignition, long service life.

With WL-20 (W + 2.2% _{La2 O3}) easy arc ignition and re-ignition, stable arc without burning-through tendency. The addition of _{La2 O3} increases the carrying capacity of the electrode by 1.5 times and the maximum current when welding with alternating current. Lanthanum electrodes as compared to WC-20 and WT-20 (with cerium and thorium admixture) are more durable, with less wear of the working end and minimal weld contamination. Uniform distribution of _{La2 O3} in the electrode, keeps its original sharpening for a long time at any welding current. Alternating sinusoidal current requires a spherical sharpening of the working end of the electrode. WC-20 The admixture of up to 2.2% of CeO oxide, the most common non-radioactive rare-earth element, to tungsten facilitates the initial arc start-up, improves electrode emission and increases the maximum welding current. These electrodes can be welded at any current characteristic. WC-20 has a more stable arc even at low voltages. WC-20 is used for orbital welding of pipes, thin sheet steel and pipelines. It is considered a disadvantage that when welding with high current values, the CeO oxide concentrates at the working end of the electrode.

Table 2. Optimal current values for tungsten electrodes in argon arc welding

electrode Ø, mm	Forward polarity	Reverse polarity	Positive and negative half-wave are equal	Negative half-wave is greater than positive half-wave
4	400 - 500	40 - 55	200 - 320	300 - 400
3.2	250 - 400	25 - 40	160 - 250	225 - 325
3	220 - 350	20 - 35	140 - 230	200 - 300
2.4	150 - 250	15 - 30	100 - 180	140 - 235
2	100 - 200	12 - 25	70 - 130	80 - 160
1.6	70 - 150	10 - 20	60 - 120	70 - 150

Buy at a bargain price

Evek GmbH offers electrodes for wholesale and retail buyers. On our site you will find all the necessary information. We are waiting for your orders.