Why Isn't Nitrogen Commonly Used as a Shielding Gas in Welding Instead of Argon?

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SUMMARY

Nitrogen is not commonly used as a shielding gas in welding due to its reactivity at high temperatures, particularly around 1500°C, where it forms nitrous oxides, compromising its inert properties. Unlike nitrogen, argon is a noble gas with a complete valence shell, making it a true inert gas that remains non-reactive at all temperatures. Additionally, argon's density prevents it from dispersing quickly, providing better shielding during the welding process. Therefore, argon is preferred over nitrogen for high-temperature welding applications.

PREREQUISITES
  • Understanding of welding processes and temperatures
  • Knowledge of gas properties, specifically inert gases
  • Familiarity with the chemical behavior of nitrogen and argon
  • Basic principles of metallurgy related to gas interactions
NEXT STEPS
  • Research the properties of noble gases in welding applications
  • Learn about the formation of nitrous oxides during high-temperature processes
  • Explore the effects of shielding gases on weld quality and integrity
  • Investigate alternative shielding gases and their applications in welding
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This discussion is beneficial for welding engineers, metallurgists, and anyone involved in selecting shielding gases for welding processes.

cragar
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Why don't they use nitrogen for welding instead of argon . Unless it does something to the metal . Nitrogen seems like it would be cheaper than argon .
 
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Nitrogen reacts with air at high temps to form nitrous oxides which aren't nice.
Not sure if they could form nitrides with the metal but they might

Argon is also heavy enough that it doesn't disperse too quickly
 
thanks for your answer , so that's probably why they don't use it .
 
Nitrogen is only a good inert gas for medium to low temperature processes. It's almost like a "fake" inert gas, because it only acts like an inert gas because it has a triple bond in its structure which is very hard to break, so it will not react in lower temperatures.

At around 1500C it will react with the air to form oxides of nitrogen, meaning it is no longer inert. Welding processes can create temperatures into several thousands of degrees. Argon on the other hand is a noble gas, having a full valence shell and is a true "inert gas" and will not react at any temperature.
 

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