DYNAMIC ANALYSIS AND CONTROL OF THE D. C. ELECTRIC-RESISTANCE BRAZING PROCESS FOR STRIP-WELDED PIPES

Dynamic analysis of the brazing process is made. First, the basic theoretical formulas for the dynamic analysis are derived, then the effects of stock cross-section fluctuation and welding velocity undulation on brazing temperature under either constant-current control or constant-voltage control are compared and studied. It shows that the constant-voltage control is an effective method of controlling brazing temperature for strip-welded pipes. It also shows that wall-thickness variations of strips should be as small as possible and the variation cycle should be as long as possible in order to ensure stable brazing temperature.