Slag that stays locked inside the weld or along its fusion line instead of floating out, typical of stick, flux-cored and submerged arc welding. Causes include incomplete slag removal between passes, notches at the toes of previous beads, low current and a poor travel angle. Inclusions show on radiographs as dark irregular shapes and are limited by length in most codes.
Two inches of slag inclusion between the hot pass and fill, grind it out and refill it.
Also heard as
- slag inclusions
- entrapped slag
- SI
Related terms
Slag
The glassy crust that forms on top of a stick, flux-cored or submerged arc weld and is chipped off.
Wagon tracks
Radiographer slang for two parallel lines of slag trapped along the edges of a root pass.
Travel angle
The tilt of the electrode or gun along the direction of travel, described as push or drag.
RT
Radiographic testing: imaging a weld's interior with X-rays or gamma rays on film or a digital detector.