High-Temperature Shielding Gas
High-temperature shielding gas is a gas mixture with hydrogen or helium, used in plasma welding and thermal spray processes. It increases the arc enthalpy and speeds up the processing rate.
Physical-Chemical Mechanism of Action
High-temperature shielding gas contains hydrogen or helium, which react at high temperatures and increase the arc enthalpy. This results in a stronger ignition and a brighter arc, which increases the processing speed.
Metallurgical Relevance & Welding Risks
The use of high-temperature shielding gas can lead to better welding results because it improves ignition and accelerates processes. However, an incorrect gas mixture or insufficient concentration can lead to problems such as incomplete melting or increased stress in the weld.
Shop Practice & Instructions
When plasma welding and thermal spraying, use a gas mixture of 90% helium and 10% hydrogen. Make sure the gas is correctly distributed in the welding zone and that concentrations are maintained. Constantly monitor temperature and ignition to achieve optimal results.