Welding Inspection & Metallurgy API ICP Self Study Notes

3.20 distortion: The change in shape or dimensions, temporary or
permanent, of a part as a result of heating or welding.
3.21 filler metal: The metal or alloy to be added in making a welded joint.
3.22 fillet weld size: For equal leg fillet welds, the leg lengths of the largest
isosceles right triangle that can be inscribed within the fillet weld cross
section.
3.23 fusion line: A non-standard term for weld interface.
3.24 groove angle: The total included angle of the groove between
workpieces.
3.25 heat affected zone (HAZ): The portion of the base metal whose
mechanical properties or microstructure have been altered by the heat of
welding or thermal cutting.