During the laser welding process of stainless steel, black discoloration on the weld bead is usually related to improper laser parameter settings or insufficient shielding gas protection.
Main Causes of Black Weld Beads:
1. Excessive Laser Power
Excessive laser power can cause excessive heat concentration in the welding area, leading to oxidation on the stainless steel surface and resulting in black discoloration of the weld bead.
Solution:
Adjust the laser power according to the material thickness and welding requirements to achieve optimal welding results.
2. Insufficient Shielding Gas
Insufficient shielding gas pressure or flow rate cannot effectively isolate the welding area from air, which may cause oxidation and discoloration of the weld bead.
Solution:
Adjust the shielding gas pressure and flow rate to ensure sufficient protection of the welding area during the welding process.
Functions of Shielding Gas:
1. Prevent Weld Oxidation
Protect the weld area from oxidation and improve the overall weld appearance and forming quality.
2. Protect the Protective Lens
Reduce the damage caused by welding fumes and spatter, helping extend the service life of the protective lens.
Proper matching of laser power parameters and shielding gas settings is the key to achieving clean, stable, and high-quality stainless steel laser welding results.
