In laser welding, shielding gas will affect weld formation, weld quality, weld penetration depth and penetration width. In most cases, blowing shielding gas will have a positive effect on the weld, but it may also cause damage. Come unfavorable effect.
The role of protective gas
positive effects
1) The correct blowing of shielding gas will effectively protect the weld pool to reduce or even avoid oxidation;
2) The correct blowing of shielding gas can effectively reduce the spatter generated during the welding process;
3) The correct blowing of shielding gas can promote the uniform spread of the weld pool during solidification, so that the weld is formed uniformly and beautifully;
4) The correct blowing of shielding gas can effectively reduce the shielding effect of the metal vapor plume or plasma cloud on the laser, and increase the effective utilization rate of the laser;
5) The correct blowing of shielding gas can effectively reduce the welding seam porosity.
As long as the gas type, gas flow rate, and blowing method are selected correctly, the desired effect can be obtained.
However, incorrect use of shielding gas will also have an adverse effect on welding.
Negative Effects
1) Incorrect blowing of shielding gas may cause deterioration of the weld;
2) Choosing the wrong gas type may cause cracks in the weld, and may also reduce the mechanical properties of the weld;
3) Choosing the wrong gas flow rate may cause more serious oxidation of the weld (whether the flow is too large or too small), and may also cause the weld pool metal to be seriously interfered by external forces and cause the weld to collapse or unevenly form;
4) Choosing the wrong gas blowing method will cause the welding seam to fail to achieve the protective effect or even basically no protective effect or have a negative influence on the welding seam formation;
5) Into the shielding gas will have a certain impact on the weld penetration, especially when welding thin plates, it will reduce the weld penetration.
