The use of shielding gas in laser welding process

Protective gas

In laser welding, the protective gas will affect the weld formation, weld quality, weld penetration and melt width. In most cases, the blowing of the shielding gas will have a positive effect on the weld, but it may also be carried. To the unfavorable role.

positive effects

1) Proper blowing of protective gas will effectively protect the weld pool from oxidation or even oxidation;

2) Proper blowing of the shielding gas can effectively reduce the splash generated during the welding process;

3) Proper blowing of the protective gas can promote uniform spreading of the weld pool during solidification, so that the weld bead is formed evenly and beautifully;

4) Proper blowing of the shielding gas can effectively reduce the shielding effect of the metal vapor plume or plasma cloud on the laser and increase the effective utilization of the laser;

5) Proper blowing of protective gas can effectively reduce weld porosity.

As long as the gas type, gas flow rate, and blowing method are correctly selected, the desired effect can be obtained. However, incorrect use of shielding gas can also adversely affect welding.

Negative Effects

1) Incorrect blowing of shielding gas may cause the weld to deteriorate:

2) Choosing the wrong type of gas may cause cracks in the weld and may also result in a decrease in the mechanical properties of the weld;

3) Choosing the wrong gas blowing flow rate may cause the weld to be more oxidized (whether the flow rate is too large or too small), or the weld pool metal may be seriously disturbed by the external force to cause the weld to collapse or form unevenly;

4) Choosing the wrong gas blowing method will result in the weld not achieving the protective effect or even the basic protection effect or negatively affecting the weld formation;

5) Insufflation of the shielding gas will have a certain influence on the weld penetration, especially when the thin plate is welded, the weld penetration will be reduced.