Isolated slag inclusions
Isolated slag inclusions are non-metallic particles in the weld that result from inadequate interpass cleaning. They can cause strengthening and stress build-up.
Physical-Chemical Mechanism of Action
Isolated slag inclusions are particles that do not fully dissolve between the metal particles during welding and remain in the microstructure. These particles can consist of chemical compounds or mechanical abrasion.
Metallurgical Relevance & Risks in Welding
These inclusions can impair the mechanical strength of the weld by acting as stress raisers and causing cracks. They can also lead to corrosion and shorten the service life of the joint.
Shop Practice & Instructions
To minimize isolated slag inclusions, it is important to clean the interpasses thoroughly. This can be achieved through careful surface treatment and the use of cleaning agents. For severe inclusions, additional welding or another repair may be necessary.