Investigation of laser-arc hybrid welding utilizing CMT, effects upon oxygen and nitrogen contents as well as the weld stability due to oxygen contents of the shielding gas and gap oxides
2015 (English)Conference paper, Presentation (Other academic)
In this study, the effects upon weld arc stability and contents of oxygen and nitrogen inside the weld is investigated for laser-arc hybrid welding (LAHW) using the CMT arc mode. CMT is a controlled short arc technique that is here expected to be less sensitive to oxygen levels in the shielding gas. Having oxides or nitrogen inside the weld region is also known to alter the fluid mechanics such as surface tension, but also a cause for porosity. The gap preparation prior to welding is typically carried out by thermal cutting, water jet cutting or grinding. These edges are then placed to form the joint to be welded. In the case of thermal cutting, oxides are usually formed on the cut edge, adding oxygen into the melt pool when welding is conducted. The effects are studied by macroscopy, HSI and chemical analysis. The arc stability and oxygen and nitrogen levels in the welds are more affected by the oxides remaining from the laser cut edges than the oxygen in the shielding gas when the cutting oxides are removed.
Place, publisher, year, edition, pages
Research subject Manufacturing Systems Engineering
IdentifiersURN: urn:nbn:se:ltu:diva-35091Local ID: 97ae6e4b-1783-4bca-958d-ae87a4c27b91OAI: oai:DiVA.org:ltu-35091DiVA: diva2:1008343
Annual Assembly by the International institute of welding (IIW) 2015 : 29/06/2015 - 01/07/2015
Godkänd; 2015; 20151127 (jankar)2016-09-302016-09-30Bibliographically approved