Now showing 1 - 3 of 3
  • Publication
    Investigation of the gap bridgeability at high-power laser hybrid welding of plasma-cut thick mild steels with AC magnetic support
    ( 2021)
    Üstündag, Ö.
    ;
    Bakir, N.
    ;
    Gumenyuk, A.
    ;
    Rethmeier, M.
    One of the challenges of the high-power hybrid laser welding of thick steels is the sensitivity of the process of the process to manufacturing tolerances. This usually leads to a time-consuming preparation of the welding edges, such as milling. The study deals with the influence of the edge quality of milled and plasma-cut steel made of S355J2 with a wall thickness of 20 mm on the laser hybrid welded seam quality. Furthermore, the gap bridgeability and the tolerances towards edge misalignment was investigated. An AC magnet was used as backing support to prevent sagging and positioned under the workpiece, to generate an upwards directed electromagnetic pressure. The profiles of the edges and the gap on the top and root side were measured using a digital camera. Single-pass laser hybrid welds of plasma-cut edges could be welded using a laser beam power of just 13.7 kW. A gap bridgeability up to 2 mm and misalignment of edges up to 2 mm could be achieved successful. Additionally, the independence of the cutting side and the welding side was shown, so that samples were welded to the opposite side to their cutting. For evaluation of internal defects or irregularities, X-ray images were carried out. Charpy impact strength tests were performed to determine the toughness of the welds.
  • Publication
    Hybrid laser Arc Welding for The Production of Longitudinally Welded Pipes
    ( 2014)
    Gook, S.
    ;
    Gumenyuk, A.
    ;
    Rethmeier, M.
    The aim of the present work is to investigate the possibilities of the hybrid laser arc welding regarding the reliable and cost effective production of longitudinal welds on the high strength pipeline steels X80 and X120 and to evaluate the achievable mechanical properties of the laser hybrid welds. The study focused on the investigations of the weld seam toughness in the low temperature range (-60 °C and -40 °C). Suitable filler materials have been identified in the context of this task. It could be shown that the metal powder filler wires, micro alloyed with Ni and partly with Cr and Mo, guaranteed sufficient Charpy impact toughness at low temperature for the both investigated materials (average value 190 J for X80 at -60 °C and 53 J for X120 at -40 °C). The modern arc technologies such as modified pulsed spray arc have been used to promote the deeper penetration of the filler material in the narrow laser weld. The edge preparation with a root face of 14 mm has been proposed as optimum, because no penetration of the filler material could be detected over this depth limit and therefor any metallurgical influences on the properties of the weld metal through the welding wire are not possible.
  • Publication
    Laserstrahl-MSG-Hybridschweißen mit hochlegierten Massiv- und Fülldrahtelektroden
    ( 2009)
    Lorenz, S.
    ;
    Kannengießer, T.
    ;
    Michael, T.
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    Gumenyuk, A.
    ;
    Rethmeier, M.
    ;
    Posch, G.