Weld heat affected zone graphitization is most frequently found in the heat affected zone adjacent to welds in a narrow band, corresponding to the low temperature edge of the heat affected zone. In multi-pass welded butt joints, these zones overlap each other covering the entire cross section. Because of its appearance, this type of graphitization is called________.
Weld heat affected zone graphitization that appears in a narrow band along the low temperature edge of the heat affected zone in multi-pass welded butt joints is called eyebrow graphitization. The term 'eyebrow' is used due to the visual resemblance of the graphitization pattern to an eyebrow shape, as it overlaps and covers the entire cross section in these zones.
The second and more damaging type of graphitization results in chains or local planes of concentrated graphite nodules. Because of its appearance, this type is also known as “eyebrow graphitization.” This form of graphitization can result in a significant reduction in load-bearing capability while increasing the potential for brittle fracture along this plane.