Tungsten inclusion
Tungsten inclusions occur in TIG welding when electrode particles contact the weld pool or from thermal overload. They cause discontinuities and increase hardness, contaminating the weld structure.
Physicochemical Mechanism of Action
Tungsten inclusions occur when tungsten particles from the electrode get into the weld pool or the electrode tip gets too hot. These particles become trapped in the weld metal and remain there as inclusions.
Metallurgical Relevance & Welding Risks
Tungsten inclusions increase the hardness of the structure, which can lead to crack-sensitive phases like martensite. They can also disrupt grain growth and impair the toughness of the material. Additionally, they often cause irregular weld structure and poor mechanical properties.
Workshop Practice & Operating Instructions
To minimize tungsten inclusions, pay attention to proper electrode care. Do not use overloaded or damaged electrodes. Make sure the weld pool is clean and temperature is controlled. At high currents or long welding times, it may be helpful to change the electrode regularly.