Dilution
Dilution is the mixing ratio between the base material and the filler metal in the weld. Optimal dilution leads to homogeneous properties and enhances mechanical performance. With uneven dilution, local stresses, embrittlement, or porosity can occur.
Physical-Chemical Mechanism of Action
Dilution describes the mixing ratio between the molten base material and the added filler metal within the solidified weld bead. This process occurs by diffusion of atoms from the filler metal into the base material, leading to a homogeneous composition.
Metallurgical Relevance & Welding Risks
Optimal dilution ensures a uniform distribution of alloying elements and enhances mechanical properties such as strength and toughness. However, an uneven dilution degree can lead to local stresses, which in turn causes embrittlement or porosity of the weld. This can affect the service life and reliability of the welded joint.
Workshop Practice & Action Guidelines
To ensure optimal dilution, it is important that the filler metal and base material are well compatible with each other. This can be achieved by choosing the right filler and using the correct welding technique. The temperature during welding as well as the dwell time must be precisely controlled to ensure homogeneous dilution. If problems with embrittlement or porosity arise, the dilution ratio should be checked and adjusted if necessary.