Dross Adhesion
Slag lip forms by the adhesion of solidified melt material on the underside of the cut kerf when the process gas is not sufficiently impulsive.
Physical-Chemical Mechanism of Action
Slag ridge forms due to inadequate removal of molten material and gases during the welding process. The process gas that normally blows these materials away lacks sufficient impulse or pressure to effectively remove all slag.
Metallurgical Relevance & Welding Risks
Slag ridge can lead to poor fusion between the weld pieces and cause cracks and fractures in the joint. It also reduces the mechanical properties of the weld by creating incomplete contact surfaces.
Workshop Practice & Action Guidelines
To avoid slag ridge, it's important to ensure that the process gas has sufficient impulse and pressure. This can be achieved by adjusting the gas pressure and impulse settings. Optimal gas coverage and correct travel speed are also crucial.