Laser welding machine welding often use inert gas for protection, inert gas is also known as rare gas, they are colorless and odorless, it is difficult to react chemically with other substances, because their chemical properties are extremely inactive, so welding often use them to isolate the air, through the nozzle mouth at a certain pressure spray to the surface of the workpiece, to avoid some gases in the air to the weld oxidation.
The role of shielding gas
1. Avoid oxidation of the workpiece during the welding process;
2. Improve the aesthetics of the workpiece after welding;
3. Prevent the occurrence of stomatal problems;
4. Expand the laser utilization rate of laser welding machine;
5. Reduce the splashing of focusing lenses during the welding process of laser welding machine;
The type of shielding gas
Shielding gas will provide favorable conditions for the formation of welds, and when there is surface oxidation of the welded material, shielding gas is required; When the welded material does not care about surface oxidation, it can also be protected without gas. There are three kinds of maintenance gases used in laser welding machines, which are helium, argon and nitrogen.
1. Argon
Argon is a very cost-effective protective gas, which is used more in laser welding, because the activity of argon is very low, almost will not react chemically with common metals, cheap price, high density, can well protect the weld.
2. Nitrogen
Nitrogen is a very affordable protective gas, but due to metallurgical problems, it is not suitable for welding certain types of stainless steel, and porosity may also occur, so it is not suitable as a welding shielding gas for all metals, and stainless steel is a very common material with limitations.
3. Helium
Helium is a more expensive protective gas, but also a more commonly used protective gas in laser welding, better than argon and nitrogen protection, can make the laser directly reach the surface of the workpiece without obstruction, but the cost of using helium is higher.
Protective gas is safe to use
1. Move the gas tank smoothly during use;
2. Set the shielding gas first, and then turn on the laser welding machine;
3. The user should stand on the side of the bottle mouth and slowly open the cylinder valve;
4. The blowing method of the protective gas can be selected according to the situation, and it is generally recommended to use the side blowing method of the side shaft;
5. Keep away from fire when storing, avoid high temperature or exposure to the sun;