Fluorescent Penetrant
Fluorescent penetrants are special penetrant liquids that glow under UV radiation and present surface flaws with high contrast. They help in detecting pores, cracks, and other defects.
Physico-chemical mechanism of action
Fluorescent agents contain chemical substances that become excitable under UV irradiation. These substances interact with the surface and then emit light in the visible spectrum, which is called fluorescence.
Metallurgical relevance & welding risks
Fluorescent agents are used to check weld quality. They can reveal pores and cracks in the weld that would not be visible to the naked eye. A missing or weak fluorescent signal can indicate that the weld is defective or was not cooled properly.
Workshop practice & instructions
Use fluorescent agents after welding, before the parts dry. Spray the medium on the weld and irradiate it with UV light. Make sure the surface is clean and free of dust particles, as these can affect the fluorescent signal. If defects are visible, redo the weld process or correct the cause of the defects.