Til hovedinnhold

Filler metal distribution and processing stability in laser-arc hybrid welding of thick HSLA steel

Filler metal distribution and processing stability in laser-arc hybrid welding of thick HSLA steel

Kategori
Tidsskriftspublikasjon
Sammendrag
Welds made by high power laser beam have deep and narrow geometry. Addition of filler wire by the arc source, forming the laser-arc hybrid welding (LAHW) process, is very important to obtain required mechanical properties. Distribution of molten wire throughout the entire weld depth is of concern since it tends to have low transportation ability to the root. Accurate identification of filler metal distribution is very challenging. Metal-cored wires can provide high density of non-metallic inclusions (NMIs) which are important for acicular ferrite nucleation. Accurate filler distribution can be recognized based on statistical characterization of NMIs in the weld. In the present study, it was found that the amount of filler metal decreased linearly towards the root. The filler metal tends to accumulate in the upper part of the weld and has a steep decrease at 45–55 % depth which also has wavy pattern based on longitudinal cuts. Substantial hardness variation in longitudinal direction was observed, where in the root values can reach > 300 HV. Excessive porosity was generated at 75 % depth due to unstable and turbulent melt flow based on morphology of prior austenite grains. The delicate balance of process parameters is important factor for both process stability and filler metal distribution.
Språk
Engelsk
Forfatter(e)
Institusjon(er)
  • SINTEF Industri / Materialer og nanoteknologi
  • Luleå tekniska universitet
År
2020
Publisert i
Journal of Manufacturing Processes
ISSN
1526-6125
Årgang
54
Side(r)
228 - 239