ARGON is an inert gas used in gas quenching, thus it has certain inherent advantages over liquid quenching media. Namely:

1. Gas quenched materials have cleaner surfaces and experience less oxidation [1]
2. Gas quenching allows for less deformities and more uniform cooling [1]
3. Gas quenching is safer [2]
4. Gas quenching poses less risk to the environment (particularly when compared to oil quenching) [2]

There are other gas quenching media, however. One (popular) gas is nitrogen. Nitrogen is more often used because it is cheaper with a faster cooling rate [3].

However, nitrogen can decarburize [3] or nitride [4] sensitive steels, whereas argon does not. Furthermore, when compared directly to nitrogen over a handful of samples, in most cases, argon quenched steel had slightly or significantly better mechanical properties [3].

References

[1] https://www.generon.com/nitrogen-quenching-system/

[2] https://www.lindeus.com/industries/manufacturing-and-materials-processing/gas-quenching-and-inerting

[3] https://www.industrialheating.com/articles/93972-comparing-argon-and-nitrogen-cooling-in-vacuum-furnaces

[4]https://www.boconline.co.uk/en/images/Principles%20of%20Quenching%20and%20Cooling_tcm410-114391.pdf