Lateral electro-conduction device and method for multi-wire submerged arc inner/outer welding of straight-seam steel pipe

A lateral electro-conduction device for multi-wire submerged arc inner/outer welding of a straight-seam steel pipe, comprising:

• a support device (1);
• a floating surface contact electro-conduction device (2);
• a lateral electro-conduction brush device (3);
• and
• a lateral electro-conduction metal plate (4);
• wherein
• the support device (1) is used to support a straight-seam steel pipe (5);
• the floating surface contact electro-conduction device (2) forms a surface contact with an outer surface of the straight-seam steel pipe (5) and is electrically connected with the straight-seam steel pipe (5);
• the lateral electro-conduction brush device (3) is located at a side of the support device (1), and the lateral electro-conduction brush device (3) comprises multiple electro-conduction brushes (3-1) and is electrically connected with the floating surface contact electro-conduction device (2);
• the lateral electro-conduction metal plate (4) is located at a side of the lateral electro-conduction brush device (3) and is electrically connected with a negative-pole wire harness of a welding machine (6);
• and
• the electro-conduction brushes (3-1) of the lateral electro-conduction brush device (3) are electrically connected with the lateral electro-conduction metal plate (4);
• in this way, an electro-conduction circuit is formed by the negative-pole wire harness, the lateral electro-conduction metal plate (4), the lateral electro-conduction brush device (3), the floating surface contact electro-conduction device (2), the straight-seam steel pipe (5) and a welding wire electrode for performing multi-wire submerged arc inner/outer welding on the straight-seam steel pipe (5, wherein the welding wire electrode connected with a positive pole of the welding machine (6) is arranged in advance in the welding seam before welding is performed on the straight-seam steel pipe (5).