METHOD OF ARC WELDING OF PIPELINES Russian patent published in 2018 - IPC B23K9/235 B23K33/00 B23K101/10 

FIELD: electricity.

SUBSTANCE: welding groove of pipes edges, pipe assembly and preheating of the pipes edges from 180 to 270°C are performed. The superposition of welding rolls, forming a butt welded joint, is carried out with the exposure of temperature between the superposed welding rollers from 200 to 270°C. Then, arc welding is performed to form an annular butt joint along the entire perimeter of the pipe. After that, the welding joint is cooled in the temperature range from 600 to 500°C with a speed of no more than 10°S/c by continuous concomitant heating of the welded joint, and cooling of the welding joint from the temperature of 500°C and below is carried out by applying heat-insulating belts. When welding, the heat input into the metal is provided in the range from 0.5 to 1.5 kJ/mm.

EFFECT: invention makes it possible to increase the load-bearing capacity of pipeline at a construction temperature below minus 50 degrees by increasing the reliability of the welding joint when performing welding operations at low temperatures.

4 cl, 1 tbl