Abstract: In a force freeze welding method and system for joining metal work pieces, a controlled and programmable electrical potential is applied to a circuit including a first work piece (130) and a second work piece (140). The first work piece (130) is linearly translated towards the second static work piece (140) to engage along a faying interface (190). The first work piece (130) and the second work piece (140) move together at a controlled rate and voltage is applied to the circuit which produces heat to soften or plasticize the faying interface (190) during a flashing stage (310). A position offset (210) or abrupt compression force is applied to at least one of the first work piece (130) and the second work piece (140) prior to applying an upset (330) to force the first work piece (130) and the second work piece (140) together to weld the first work piece (130) and the second work piece (140) along the faying interface (190).

Abstract: An electric resistance welder welds, hot reduces, tempers and planishes overlapped metal workpieces. The welder incorporates two transformers (50, 60) which are connected to two sets of wheel electrodes (26, 28 and 36, 38). Electric current from a first transformer (50) flows through workpieces (16) and returns through a second transformer (60). The first set of wheel electrodes (26, 28) creates a weld joint and the second set (36, 38), depending on the shape, area, and pressure of the wheels, either reduces the weld thickness, tempers the weld joint, or both. A control circuit (72) includes a current sensor (70) and power factor adjuster (80). The current sensor senses current flow through the first transformer during the welding process. As the current changes, particularly when the sets of wheel electrodes engage and disengage the workpieces, the power factor adjuster (72) adjusts the power factor to maintain constant heat to the workpieces.