Magnetic Leakage Flux
Stray flux is the magnetic field that occurs at surface cracks or material interruptions in ferromagnetic materials and attracts magnetic indicators.
Physical-Chemical Mechanism of Action
Flux leakage occurs due to the excitation of electrons in the atomic nuclei of the material by magnetic fields. These excited electrons generate their own magnetic field, which differs from the original field and attracts magnetic indicators.
Metallurgical Relevance & Welding Risks
Flux leakage can occur if there is a lack of or insufficient deoxidation in the weld, leading to porosity. These pores can contaminate the material and impair mechanical properties. Furthermore, flux leakage can cause indicators to show false cracks or defects, leading to unnecessary repair.
Shop Practice & Working Instructions
To minimize flux leakage, careful deoxidation is essential. Use high-quality shielding gases and ensure the correct application of protective agents. During cooling, the workpiece should be cooled slowly and evenly to avoid porosity. When inspecting with magnetic indicators, it is important that the operator is aware of the possible causes of flux leakage to avoid false diagnoses.