Thorium oxidesZirkonium oxidesLanthan oxidesCerium oxides ThOZrOLaOCeO 22232 Rare materials ????????????????????? > To improve the fusion pointՕTo improve ignition properties To improve arc control ՕTo avoid pollution of weld pool > 3 size="-2">

Chemical designation=W Density=19.3 g/cmFusion point= 3.380 C Boiling point=6,000а C > 3 Designation = WՕColour code= Green > AC welding, fine arc control > ՕDC welding. Very poor ignition properties and arc controlTendency towards dropping Tungsten particles into the weld pool in connection with ignition > 4 size="-1">

Designation= WT 10=0.9 - 1.2 % thorium oxideՕColour code= Yellow Designation= WT 20=1.8 - 2.2 % thorium oxide ՕColour code= Red Designation= WT 30=2.8 - 3.2 % thorium oxide ՕColour code= Lilac Designation= WT 40=3.8 - 4.2 % thorium oxide ՕColour code= Orange > DC weldingՕWhen contents of Thorium oxide increase, electrical resistance will decline whereby the electron liberation will improveThis improves ignition properties, lifetime and current load, at the same time the fusion point increasesՕHigh fusion point (approx. 3,600 C for WT 20) > ЕPoor ability to establish a shiny surface on the electrode...

Designation= WZ 4 = 0.3 - 0.5 % zirconium oxideՕColour code= BrownDesignation= WZ 8 = 0.7 - 0.9 % zirconium oxideՕColour code= White > AC weldingՕNo dropping of Tungsten particles into the weld pool >

Designation= WL 10 = 0.9 - 1.2 % lanthan oxideՕColour code= BlackDesignation= WL 20 = 1.8 - 2.2 % lanthan oxideՕColour code= Blue > Both AC and DC weldingՕNo tendency towards slagging Longer lifetime than WT electrodes ՕProduces a shiny surface in AC welding Higher fusion point than W-electrodes (3600հC for WL 10) No dropping Tungsten particles into the weld pool in connection with AC welding ignition. > ՕWL 10 (Lanthanated) cannot be loaded as much as WC (Ceriated) electrodes as on ignition they start to drop Tungsten particles into the weld pool, since they have a lower fusion point than WC...

Designation= WC 10 = 0.8 - 1.2 % cerium oxideՕColour code= PinkDesignation= WC 20 = 1.8 - 2.2 % cerium oxideՕColour code= Grey > Both AC and DC weldingՕNo tendency towards slagging Fine ignition properties > ՕDC welding causes more wear on electrodes than WL 20 (blue) > 8 size="-1">

Designation = WS 2 = ? % rare materialsՕColour code= Turquoise > Both AC and DC weldingՕSmaller tendency towards slagging than WT (Thoriated) AC welding produces a surface on the electrode point > ՕNo details on chemical contentDC welding causes more wear on electrodes than WL 20 (blue)shiny > 9 size="-1">

D smallerthan 2.5 mm D largerthan 2.5 mm Approx. 2D Approx. 1.5D >

Test period: week 52, 1997Participants: Tests were carried out on standard AC/DC Niels-Jrgen Christiansen, AMU Center, machines. Please note that test results (such Randersas current intensity, re-ignition properties Stig Jensen, Migatronic(HF), (ACt-balance), (ACi-balance), (current frequency) and (electrode preheating) may Tests were carried out to demonstrate be different if other welding machines and whether there are any types of Tungsten shielding gases are used.electrodes available that can be used as alternatives to pure Tungsten electrodes for All AC tests were carried out on a AC welding...

Type of electrode Comments Green: WP Pure Tungsten Drops the point at 100 amp. Red: WT 20 2% Thorium oxide Fusion at 180 amp. Orange: WT 40 4% Thorium oxide Fusion at 180 amp. Grey: WC 20 2% Cerium oxide Fusion at 180 amp. Black: WL 10 1% Lanthan oxide Fusion at 180 amp. Blue: WL 20 2% Lanthan oxide Fusion at 180 amp. Turquoise: WS 2 ? % Rare materials Drops the point at 140 amp. > 17 size="-1">

Type of electrode Comments Blue: WL 20 2% Lanthan oxide The point forms a small, shiny ball at 150 amp.A ball with dia. like elec. is formed at 180 amp. Drops Tungsten at 220 amp. Arc becomes unstable at 240 amp. Red: WT 20 2% Thorium oxide The point gets a coarse structure at 100 amp. Drops Tungsten at 220 amp. Arc becomes unstable at 260 amp. Green: WP Pure Tungsten The point forms a small, shiny ball at 50 amp. A ball with dia. like elec. is formed at 80 amp. The ball gets a larger dia. than elec. at 140 amp.Drops Tungsten at 200 amp. Arc becomes unstable at 200 amp. Grey: WC 20 2% Cerium...

Type of electrode Comments The point gets a coarse structure at 80 amp.A ball with dia. like elec. is formed at 140 amp. Burns down on one side at 200 amp. Drops Tungsten at 260 amp. Arc becomes unstable at 260 amp. Red: WT 20 2% Thorium oxide The point forms a small ball at 30 amp. A ball with dia. like elec. is formed at 60 amp. The ball gets a larger dia. than elec. at 100 amp.Drops Tungsten at 180 amp. Arc becomes unstable at 180 amp. Green: WP Pure Tungsten The point forms a small ball at 90 amp. A ball with dia. like elec. is formed at 160 amp. The ball does not get a larger dia. than elec....

See illustration no. 3 Comments The reason may be the almostmaximum load of the electrode. Very fine ignition, produces a shiny ball withthe same dia. as the electrode diameter. Electrode was tested at 180 amp, because the peak load is lower than for other electrodes. Stops after 20 ignitions, since large quantities of Tungsten are dropped into the weld pool. Verycoarse structure of the point after a few stitch weldings. Very fine ignition, but produces a shiny and vibrating ball much larger than the electrodediameter. Fine ignition, produces a shiny ball which is a little larger than the electrode...

See illustration no. 4 Comments Stable arc.The point remains intact. Stable arc.More and more slag is produced. The point becomes deformed. After a few ignitions the point was dropped.Ignites up in the gas nozzle.Very unstable arc. Stable arc.More and more slag is produced. The point becomes deformed. Stable arc. The point remains intact. Stable arc.Does not ignite from the electrode point, butabove the point.A small fine ball is produced rather quickly onthe point and maintained. Stable arc.More and more slag is produced. The peak becomes deformed. Total evaluation Parent mat.: Stainless steel...