How to use “gas” correctly in laser welding
The role of protective gas
In laser welding, shielding gas will affect the weld formation, weld quality, weld penetration and penetration width. In most cases, blowing shielding gas will have a positive effect on the weld, but it may also bring adverse effect.
1) Correctly blowing shielding gas will effectively protect the weld pool from reducing or even avoiding oxidation;
2) Correctly blowing in the shielding gas can effectively reduce the spatter generated during the welding process;
3) The correct blowing of the protective gas can promote the uniform spreading of the weld pool when it solidifies, so that the weld is formed uniformly and beautifully;
4) Correctly blowing in the protective 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) Properly blowing shielding gas can effectively reduce weld pores.
As long as the gas type, gas flow rate and blowing method are selected correctly, the ideal effect can be obtained.
However, improper use of shielding gas can also have adverse effects on welding.
1. Improper insufflation of shielding gas may result in poor welds:
2. Selecting the wrong type of gas may cause cracks in the weld and may also reduce the mechanical properties of the weld;
3. Selecting the wrong gas blowing flow rate may lead to more serious oxidation of the weld (whether the flow rate is too large or too small), and may also cause the weld pool metal to be seriously disturbed by external forces, causing the weld to collapse or form unevenly;
4. Choosing the wrong gas blowing method will cause the weld to fail to achieve or even have no protective effect or have a negative impact on the weld formation;
5. Blowing in the shielding gas will have a certain effect on the weld penetration, especially when welding thin plates, it will reduce the weld penetration.