High-Frequency Resistance Welding of Structural Shapes

The high-frequency welding process, based on 450-kcal resistance heating and subsequent forge welding is shown to be a versatile, productive, and highly economical method of producing lightweight structural beams. A single high-frequency welding line can produce 4-to 18-in I or H beams with up to ¿-in webs and ¿-in flanges, in a single pass, from three coiled strips, in ferrous or nonferrous materials at production welding rates of 20 to 150 ft/min depending on high-frequency generator and system size. Beams can be produced interchangeably, in special section shapes, asymmetric or hybrid configurations, as well as ``standard´´ sizes in improved form for increased section strength. Discussion includes process principles, metallurgical weld details and test results, production equipment description and capabilities, conversion costs, and significant market areas for high-frequency welded shapes.