METHOD AND DEVICE FOR PRODUCING THIN WALLED ELECTRIC WELDED PIPE

摘要

PURPOSE:To produce a thin walled electric welded pipe while eliminating thoroughly end face strain by inserting a metallic bar or strip between forming rolls from diagonally above and subjecting the bar or strip to repeated forming while applying always an upward camber to the formed good. CONSTITUTION:An auxiliary device 6 which is adjustable in a vertical position is provided below a flat metallic bar or strip to be used as a material 5 to be formed and the material 5 is inserted to the 1st roll 4 by which an upward camber is given to a formed good 7. An auxiliary device 8 which is adjustable in a vertical position is provided to the lower part of the good 7 and is inserted into the succeeding 2nd roll 9 again from diagonal above. Such operation is repeated to form the steel rod or strip. The upward camber is thus given to the formed good and tension is exerted to the side end by which end face strain is thoroughly eliminated.