摘要 |
<p>Links for heavy duty chains used by ships or in off-shore oil well drilling rigs can be made with increased strength by the use of electron beam or plasma-arc welding. A steel bar is first bent to form an ellipse with the joint lying on the minor axis of the ellipse. A bridge piece with its ends shaped to match the curved surface is then placed in position. The joint is then welded with an electron beam or plasma arc which fuses the ends of the bar to each other and also fuses the end of the bridge piece to the bar. Using an electron beam or plasma arc, avoids the formation of an excessive weld bead, which would have to be removed before joining on the next link.</p> |