Linear Slag Trail
Linear slag stringer: slag inclusions running in the welding direction between weld beads can cause porosity and increased stress.
Physical-Chemical Mechanism of Action
The linear slag string forms from droplets of liquid that run together between the weld beads. These droplets join into long, thin strands, forming the linear slag string.
Metallurgical Relevance & Risks in Welding
The linear slag string can cause porosity, which weakens the material. It also increases stresses in the weld, which can lead to cracks and hot cracks. A high number or very thin slag strings can also impair the mechanical strength of the overall weld joint.
Workshop Practice & Action Instructions
To minimize the linear slag string, it is important to ensure a clean weld pool and winding environment. High airflow and a good deoxidizer can help reduce slag carryover. Optimal winding pressure and correct welding speed also prevent the droplets from running together.