which country holds the largest producer of that substance?
China
Tungsten
China remains the world's leader not only in production, but also in export and consumption of tungsten products. 
what is gas tungsten arc welding? It is an arc welding process that uses a non-consumable tungsten electrode to produce the weld. is there a gas used in this welding process? Yes, shielding gas what specific gas is used? Helium why are such gases used in this process? To protect the welding area from atmospheric gases. what are some of the applications of this process? Its used in welding thin workpieces, manufacture of space vehicles, bicycle industry, etc. what is that electrode which is used in this process made up of? Tungsten what is the melting point of this substance? UNANSWERABLE can you name a few alloys from the substance mentioned above? High speed steel and quenched (martensitic) tungsten steel.
wiki:19589539
Tungsten [SEP] Production
The tungsten production gradually increases outside China because of the rising demand. Meanwhile, its supply by China is strictly regulated by the Chinese Government, which fights illegal mining and excessive pollution originating from mining and refining processes. Tungsten is considered to be a conflict mineral due to the unethical mining practices observed in the Democratic Republic of the Congo.