Metallic particle inclusion
Residual filler material is unintentional foreign metal or chemical additions in the weld metal, which can cause local microstructure changes and potential differences. These lead to poor weld quality.
Physical-Chemical Mechanism of Action
Residues of filler materials are metal particles or chemical additives that unintentionally get into the weld metal. These may not fully melt during the welding processes and remain embedded in the structure. They affect the microstructural development of the weld metal and can cause local changes in the chemical composition.
Metallurgical Relevance & Welding Risks
Residues of filler materials lead to local structural changes, such as the development of hard or soft spots in the weld. This can cause cracks, destruction, and reduced mechanical properties of the weld metal. Additionally, they can lead to corrosion effects and uneven stresses between the weld metal and the base metal wall.
Workshop Practice & Instructions
To minimize residues of filler materials, all welding materials and equipment should be thoroughly cleaned. Use clean protective clothing and gear. If you suspect residues, do a detailed surface cleaning before starting the welding process. Regularly check the quality of the materials used and contact the supplier if you notice any issues.