An electric resistance welded pipe or tube comprises a weld portion in a pipe or tube longitudinal direction, wherein a maximum value of a wall thickness distribution of the weld portion is less than or equal to 1.05 times an average wall thickness of the electric resistance welded pipe or tube, a width of a weld metal in the weld portion in a circumferential direction is 1 m or more and 800 m or less over an entire thickness of the electric resistance welded pipe or tube, and a ratio of a maximum value to a minimum value (=maximum value/minimum value) of the width of the weld metal is 1.0 or more and 2.5 or less.

An electric resistance welded pipe or tube comprises a weld portion in a pipe or tube longitudinal direction, wherein a maximum value of a wall thickness distribution of the weld portion is less than or equal to 1.05 times an average wall thickness of the electric resistance welded pipe or tube, a width of a weld metal in the weld portion in a circumferential direction is 1 m or more and 800 m or less over an entire thickness of the electric resistance welded pipe or tube, and a ratio of a maximum value to a minimum value (=maximum value/minimum value) of the width of the weld metal is 1.0 or more and 2.5 or less.

The invention belongs to the technical field of photovoltaic preparation equipment, in particular to a battery string typesetting and welding all-in-one machine, which comprises a frame, wherein a cross beam is arranged on the frame; A battery string transmission device arranged on the frame below one end of the cross beam; A typesetting deviation correcting device arranged at one end of the beam; A vacuum receiving device arranged in the middle of the rack; A battery string welding device arranged at the other end of the beam; The control device arranged on the frame comprises a control box arranged on the frame, and a controller and a touch display screen are arranged on the control box. By integrating the function of the typesetting machine and the welding, and optimizing the transmission structure, the invention simplifies equipment design, improves production processes, enhances efficiency, reduces costs, and maximizes economic benefits.

Disclosed are a steel pipe for a line pipe having excellent low temperature toughness in a welded zone thereof, and a method for manufacturing the same, in which alloy components and a ratio thereof are controlled, and high frequency heat-treatment is carried out on the welded zone, and immediately thereafter, a cooling process is performed thereon in a strictly controlled manner, thereby improving the low temperature toughness of the welded zone, such that a resulting steel pipe is suitable for use in a pipeline and an offshore structure.

Disclosed are a steel pipe for a line pipe having excellent low temperature toughness in a welded zone thereof, and a method for manufacturing the same, in which alloy components and a ratio thereof are controlled, and high frequency heat-treatment is carried out on the welded zone, and immediately thereafter, a cooling process is performed thereon in a strictly controlled manner, thereby improving the low temperature toughness of the welded zone, such that a resulting steel pipe is suitable for use in a pipeline and an offshore structure.