Due to the high temperature in the heat treatment process, many products will oxidize, and it is necessary to create a non-oxidizing environment. The common solution is to place the metal in a protective atmosphere (such as nitrogen), so that the metal and oxygen are isolated from each other, and then do processing. The purity of nitrogen used is relatively high, and it is necessary to maintain a continuous and stable supply to ensure that the metal workpiece has a good heat treatment effect.

Nitrogen is widely involved in all aspects of heat treatment：

(1) Vacuum heat treatment: When nitrogen is used as the cooling medium for nitrogen filling and pressurizing oil quenching, the nitrogen pressure of the nitrogen making machine is adjusted, the hardening of the steel parts is improved, and the electric heating elements of the vacuum furnace are protected.

(2) Controlled atmosphere: Nitrogen, as a dilution gas, can reduce the consumption of raw gas and reduce the formation of carbon black.

(3) Carburizing and nitriding: The nitrogen produced by the nitrogen machine can be used for anti-oxidation cooling after carburizing, reducing the internal oxidation degree of steel parts, improving the decomposition rate of furnace gas and the fatigue strength and breaking resistance of parts.

(4) Protection gas and safety gas: blowing and venting in the furnace, sealing the gas curtain of the furnace door; When the gas is cut off, the nitrogen produced by the nitrogen maker can be sent into the furnace to prevent the explosion of the furnace gas.