Thorium oxide-containing tungsten electrodes
Thorium oxide-containing tungsten electrodes improve arc starting through their high conductivity and extend torch life. They reduce porosity and increase weld strength.
Physikalisch-chemischer Wirkmechanismus
Thorium oxide (ThO2) in tungsten electrodes improves electrical conductivity by stabilizing the electric field in the arc. This results in a faster and safer ignition process.
Metallurgical Relevance & Welding Risks
Reduced porosity improves the mechanical strength of the weld, which means higher toughness and lower susceptibility to cracking. However, too high a thorium content can alter the microstructure and lead to increased hardness, causing stress concentrations and possible cracks in the material.
Werkstattpraxis & Handlungsanweisungen
Use thoriated tungsten electrodes at high voltage values or when rapid ignition is required. Make sure to use the correct thorium content (usually 1-2 %) to achieve optimal properties. With inexperienced handling, too high a thorium content can alter the microstructure and lead to cracking.