Can bright annealing be done with only nitrogen as a protective gas?

Nitrogen source for bright quenching, bright annealing, nitriding, nitrocarburizing, soft carbonization and other heat treatments; shielding gas in welding and powder metallurgy sintering process, etc.

It is possible to use only nitrogen.

I have only heard that nitrogen is used as a shielding gas, but it is generally ammonia as a shielding gas for bright annealing. The specifics are not very clear, this year's November 13th heat treatment seminar is going to start, you go to participate there are professional bright annealing experts, they should know. --Yuyao Xingda Metal Mesh Belt Factory provides.

Reasons for using nitrogen as a protective gas for the car:

1. It is stable in nature and does not react chemically with food.

2. Non-toxic. Third, the first extensive, the market value is cheap.

Nitrogen, which is usually a colorless and odorless gas, is generally less dense than air. Nitrogen is one of the main components of air. At standard atmospheric pressure, nitrogen becomes a colorless liquid when cooled to a point and liquid nitrogen becomes a snow-like solid when cooled to a point where it is cooled.

The chemical properties of nitrogen are not active, and it is difficult to react with other substances at room temperature, so it is often used to make antiseptics. However, under high temperature and high energy conditions, it can undergo chemical changes with certain substances and be used to make new substances useful to human beings.

No new substances are produced The reason for using nitrogen as a protective gas is that nitrogen is chemically inactive.

It's not easy to react with other substances, so it's like something is surrounded by a layer of nitrogen, and the other substances around it are outside the nitrogen layer.

Nitrogen (N2), a colorless and odorless gas, is one of the main components of air. Nitrogen gas accounts for the volume fraction of the total amount of the atmosphere), which is less dense than air.

at standard atmospheric pressure.

, when nitrogen is cooled to, it becomes a colorless liquid, and when cooled, liquid nitrogen.

Turns into a snow-like solid. Nitrogen is often used to make preservatives.

Under high-temperature and high-energy conditions, it can be used to produce new substances that are useful to human beings. Nitrogen is a colorless and odorless gas under normal conditions, with a melting point of 63K, a boiling point of 77K, and a critical temperature of 126K, which is difficult to liquefy. Solubility.

Very small, at atmospheric pressure at 283 k, one volume of water can dissolve the volume of nitrogen.

a. Nitrogen as protective gas is to use the stability of nitrogen, which is a chemical property, so the choice is wrong;

b. The use of dry ice as a refrigerant is the sublimation of dry ice, which is a physical property, so the choice is correct;

c. Hydrogen as fuel is the flammability of hydrogen and belongs to chemical properties, so the choice is wrong;

d. The use of oxygen in steelmaking is to use the combustible properties of oxygen, which is a chemical property, so the choice is wrong; Therefore, choose B

Pick B because it uses dry ice for sublimation.

Because hydrogen is much more reducible than nitrogen, it can protect the steel coil from oxidation.

Nitrogen is just an inactive gas, and the main principle of nitrogen protection is to "force away" oxygen and prevent oxidation reaction between oxygen and metal at high temperatures.

Hydrogen, on the other hand, is a reducing gas that can not only force away the air, but more importantly, it can be replaced by a reduction reaction with the oxidized metal at high temperatures.

In terms of effect, under the ideal state, the nitrogen protection board is what it looks like before annealing and after annealing, while the hydrogen protection board is rusty before annealing and the rust is gone after annealing, and the surface quality of the hydrogen protection board is better. Now there are pure hydrogen furnaces, as well as nitrogen-hydrogen mixing furnaces for ammonia decomposition.

You can use nitrogen, but hydrogen is much more reducible than nitrogen, and it can protect the coil from oxidation.

The hydrogen molecules are relatively small, which is conducive to the transfer of heat energy in the steel coil.

Nitrogen is an inert gas with poor reducibility, and it is okay if the black zone is removed.

The chemical properties of nitrogen are very inactive, only under high temperature, high pressure or discharge, and it is non-toxic and non-polluting, so nitrogen can be used as a protective gas for burning food under conventional circumstances.

1. It is stable in nature and does not react chemically with food.

2. Non-toxic. Third, the first extensive, the market value is cheap.

Because nitrogen is chemically stable, it does not easily react with other substances under normal circumstances, and therefore does not react with food and spoil.

It is also important to note that nitrogen itself is non-toxic and harmless, and does not directly harm the human body. Otherwise, even if the food does not react with it and spoils, it will poison the person ...... death

Inert gas can be used for protection, mainly depending on your cost. You can also anneal in a vacuum. You can ask for details.

Suzhou Qiaojia furnace industry ****.

a. Nitrogen do.

Protective gas. It is the use of the stability of nitrogen, which is a chemical property, so the option is wrong; b. Dry ice.

Used as a refrigerant, dry ice is endothermic sublimation, which is a physical property, so the choice is correct;

c. Hydrogen is hydrogen as fuel.

flammability, which is a chemical nature, so the option is wrong;

d. Oxygen is used in steelmaking by using oxygen.

flammability, which is a chemical property, so the option is wrong; Therefore, choose B

The free nitrogen in the air has always been regarded as a lazy gas. It doesn't seem to be interested in anything, neither helping to burn nor sustaining life. For the first time, nitrogen was written as "light" which means: "It dilutes the oxygen in the air." ”

People use the solitary temper of nitrogen to serve humanity. Many light bulbs are filled with nitrogen because this slows down the evaporation of tungsten filament. In a thermometer measuring a temperature of 300 500, the top of the mercury column is often filled with nitrogen, so that the mercury will not boil and oxidize when exposed to high temperatures.

In some museums, valuable and rare pages and scrolls are kept in cylinders filled with nitrogen. Because borers can't survive in nitrogen, they can't trick or treat. This year, our country has also shrouded its grain in huge plastic curtains, which have been pumped out of the air and filled with nitrogen.

In this way, mold and moths can not survive, and can inhibit the respiration of food, so that food can be safely stored for a long time. This new method of preserving grain is called "vacuum nitrogen storage."

Nitrogen is usually lonely and does not like to take care of other people's affairs, but in the heat, he becomes like an enthusiastic young man. This has brought a lot of trouble to the steelmaking mill, when steelmaking, the steel becomes fiery red molten steel, and at high temperatures, nitrogen is easily dissolved in the molten steel. However, when the ingot cools, the nitrogen escapes, and as a result, bubbles form in the ingot.

In this way, honeycomb steel cannot make machines. Now steelmakers add titanium to the molten steel. Titanium can be combined with nitride to form slag, and titanium nitride floats on top of the molten steel.

The material to be calcined is placed in a closed container, in which air is extracted, filled with nitrogen, and then heated and calcined. This is done to prevent oxidation.