High-performance welding device for thick-wall electrogas upright welding based on liquid nitrogen rapid cooling assistance

A high-performance welding device for thick-wall electrogas upright welding based on liquid nitrogen rapid cooling, wherein the welding device characterized in that the high-performance welding device comprising a welding torch (17), a back water-cooling assembly, and a front water-cooling assembly;

• the welding torch (17) is used for welding a welding groove through electrogas upright welding;
• the back water-cooling assembly is arranged on a back side of the welding surface of the thick plate (1) to be welded for performing water-cooling on a back side of the welding surface;
• the front water-cooling assembly is arranged on the welding surface of the thick plate (1) to be welded and moves with the welding torch (17);
• the front water-cooling assembly comprises a water-cooling slider (4) and a protective gas channel (7), a cooling water channel (12), and a liquid nitrogen injection channel (13) arranged inside the water-cooling slider (4);
• the protective gas channel (7) is used for providing protective gas during welding process;
• the cooling water channel (12) is used for introducing cooling water during the welding process to cool the water-cooling slider (4);
• the liquid nitrogen injection channel (13) is used for spraying liquid nitrogen onto a welded joint during the welding process to achieve local rapid cooling of a heat-affected zone of the welded join,
• wherein the protective gas channel (7) is arranged at a center of the water-cooling slider (4);
• a first water inlet (6) and a first water outlet (8) of the cooling water channel (12) are arranged on two sides of the protective gas channel (7), respectively;
• two liquid nitrogen injection channels (13) are arranged on two sides of the first water inlet (6) and the first water outlet (8), respectively,
• wherein each of the two liquid nitrogen injection channels (13) is provided with a first liquid nitrogen injector (5) and a second liquid nitrogen injector (9) therein;
• center lines of the first liquid nitrogen injector (5) and the second liquid nitrogen injector (9) are respectively distanced 1 mm to 2 mm away from outside of a weld fusion line;
• distances between ends of the first liquid nitrogen injector (5) and the second liquid nitrogen injector (9) to the welding surface of the thick plate (1) to be welded is 1 mm to 3 mm,
• wherein when a wall thickness of the thick plate (1) to be welded is greater than 30 mm and less than 50 mm, the welding groove is a single-sided V-groove, the back water-cooling assembly comprises a back water-cooling backing plate (2) and a water-cooling pipe (3) arranged inside the back water-cooling backing plate (2);
• the back water-cooling backing plate (2) is arranged along a length direction of the thick plate (1) to be welded at a root of the welding groove to be welded and clamped tightly to the thick plate (1) to be welded;
• the water-cooling pipe (3) is distributed in a serpentine pattern inside the back water-cooling backing plate (2) , and the back water-cooling assembly is applied to cool the back side of the welding surface in a way of indirect water-cooling;
• wherein that when the wall thickness of the thick plate (1) to be welded is greater than or equal to 50 mm, the welding groove is an X-groove, during welding of a first side, the back water-cooling assembly comprises a cooling water pipe (15), and the cooling water pipe (15) moves synchronously with the front water-cooling assembly during welding for spraying water towards a root of the welding groove, and the back water-cooling assembly is applied to cool the back side of the welding surface in a way of direct water-cooling;
• during welding of the other side, the back water-cooling assembly comprises a back water-cooling backing plate (2) and a water-cooling pipe (3) arranged inside the back water-cooling backing plate (2);
• the back water-cooling backing plate (2) is arranged at the root of the welding groove to be welded along a length direction of the thick plate (1) to be welded and clamped tightly to the thick plate (1) to be welded;
• the water-cooling pipe (3) is distributed in a serpentine pattern inside the back water-cooling backing plate (2), and the back water-cooling assembly is applied to cool the back side of the welding surface in the way of indirect water-cooling.