Forming gas is a mixture of hydrogen (the molar fraction can be different) and nitrogen . Sometimes a mixture is called "split ammonia medium", or "split ammonia medium", according to a chemical reaction, as a result of which this mixture is formed:
- 2 NH 3 → 3H 2 + N 2
Molding gas can be produced using thermal decomposition of ammonia in an ammonia splitter or in a molding gas generator [1] .
Molding gas is used as a medium for processes that require hydrogen properties. Forming gas, as well as hydrogen gas, is explosive. The lower explosion limit for 100% hydrogen is about 4%, and for molding gas - 5.6% at room temperature. At higher gas temperatures, this boundary, respectively, decreases. The mixture is used in chambers for gas hypersensitization, the process during which the film is heated by molding gas, it allows you to remove moisture and oxygen from it, and also increase the level of basic veilization. Hypersensitization is used in astrophotography of deep space, which deals with low-intensity input light, requires long exposures, and therefore is especially sensitive to film pollution [2] .
Molding gas is also used for catalysis in glove boxes [3] , as well as a medium for normalization processes (metallurgy). Gas is also used as a reducing agent for low- and high-temperature soldering and welding, to eliminate oxidation of the weld, using flux.
Quite often, molding gas is used in metallurgical furnaces for normalization, for heat treatment of steel, since it reduces the level of oxides on the metal surface.
See also
- Welding consumables
Notes
- ↑ Ammonia cracker for the generation of forming gas . The circulation date is 19 april, 2009.
- ↑ Lodriguss, Jerry Gas hypersensitization . Catching the light . The circulation date is 19 april, 2009.
- ↑ About the consolidation of the sovereign sanitary rules "The Basic Sanitary Rules for the Protection of the Radiatic Security of Ukraine" (12.1.20) unopened (unavailable link) . Date of treatment 27 lipnias, 2013. Archived on January 29, 2016.