STP755: A Portable 100-kW Electron Beam Welding System for Pressure Vessel Fabrication

    Farrell, WJ
    Senior Vice President, Sciaky Brothers, Inc., Chicago, Ill.

    Pages: 29    Published: Jan 1982


    Abstract

    A program to demonstrate the application of a 100-kW portable electron beam (EB) welding system to the production of girth welds in several pressure vessel shells in an industrial environment is detailed. Three-metre-diameter shells, one 80-mm-thick 304L, the other 135-mm-thick ASTM A 533 Type B, were EB welded to ASME Boiler and Pressure Vessel code requirements without the use of a large vacuum chamber. Drawing upon this experience, the author presents a manufacturing plan for applying EB welding in the fabrication of thick-wall pressure vessels.

    Potential fabrication cost savings are described in terms of a measure of welding time called Joint Completion Rate expressed in hours per foot of completed weld seam for 203-mm (8-in.)-thick plate. The values are: submerged arc welding (downhand), 3.0 h/ft; manual arc welding, 40 h/ft; and EB welding, 0.067 h/ft. Energy input is calculated for 135-mm-thick plate to be 7338 kJ/in. for submerged arc and 636 kJ/in. for EB welding.

    The results of testing a series of EB butt welds in 63.5-mm (2½-in.)-thick ASTM A 387 Grade 22 (2¼Cr-1Mo) produced without preheat or postheat, and subjected to various postweld heat treatments, are summarized. A T1 of −107°C (−160°F) and a T2 of −50°C (−58°F) were obtained.

    Additional inherent benefits of EB welding thick plate are described.

    Keywords:

    portable electron beam, thick-wall pressure vessels, potential fabrication cost savings, properties of electron beam weld 2¼Cr-1Mo steel


    Paper ID: STP28421S

    Committee/Subcommittee: A01.06

    DOI: 10.1520/STP28421S


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