Oxide Inclusion Line
Oxide stringers: Trapped metal oxides in the weld metal, caused by poor shielding gas coverage or insufficient cleaning. They interrupt metallic continuity and weaken the structure.
Physico-chemical mechanism of action
Oxidation lines form when metal is in contact with air or moisture and is not fully protected by shielding gas. This causes a reaction between the metal and the oxygen in the environment, producing metal oxides.
Metallurgical relevance & risks in welding
Oxidation lines interrupt the metallic continuity of the weld, leading to cracks and loss of strength. They can also serve as a source of corrosion and reduce the service life of the component.
Workshop practice & instructions
To avoid oxidation lines, it is crucial to keep the shielding gas coverage optimal during the welding process. The surface of the metal must be thoroughly cleaned and dry before welding. In long welding processes, regular gas flow checks should be carried out to ensure there are no air entrances.