Penetration welding method for t and l thick plate joints

Abstract

The invention discloses a penetration welding method for T and L-shaped thick plate joints. First, a wheel-type groove cutting machine is used to cut the groove of the workpiece, so that the angle of the groove surface is uniform, and the blunt edge of the groove and the cutting edge are controlled. Deviation; adjust the angle of workpiece placement, place the workpiece at an angle of 25 to 30° on the ground, and make the welding wire extension line at the joint center of the workpiece during welding; check the positioning solder joints, and remove the influential positioning solder joints on the front with carbon arc gouging. Before reverse submerged arc welding, remove all positioning solder joints, and use a grinding wheel to grind and correct the carbon plane; adopt the method of reducing the thickness of the blunt edge and sealing the bottom with gas shielded welding to eliminate hidden dangers at the joints of traditional welding processes, and use gas shielded welds as the basis Submerged arc welding molten pool pad; adjust the parameters of the welding machine to match, and the first weld on the front and back is welded with high current and medium voltage; enhance the lighting intensity of the construction area and improve the operating environment. By using the method, the pass rate of the first detection of the weld seam is improved, and the appearance quality of the weld seam is improved.

Description

technical field [0001] The invention relates to a method for penetration welding of T-shaped and L-shaped thick plate joints. Background technique [0002] The I-shaped or box-shaped solid web structural parts welded by thick plates are more and more widely used in large-scale projects such as bridges, large venues, high-rise buildings, and power plants. T, L-shaped thick plate joint penetration welding has become the largest processing of thick plate steel structures Technical obstacles. In the early days, thick plate welding was mostly applied to compression members of non-penetration welding. In recent years, the development of steel structures has advanced by leaps and bounds, and the scope of application has become more and more extensive. Penetration welding of thick plates has also been developed accordingly. Due to the limited knowledge and experience accumulation in this area, people continue to use the same kind of thin plate penetration welding (using the larger...

AI Technical Summary

Problems solved by technology

[0003] 1. The cutting angle of the groove is not uniform, and the end of the welding wire is likely to be in contact with the groove surface during welding. During cover welding, in order to completely cover the edge of the groove, the number of covers can only be increased to make up for its defects. In this way, the welding workload will be increased, the weld will be overburned, and the quality of the weld will be affected.

The quality of the weld is not ideal, the amount of welding consumables used is large, and the welding labor is increased

[0004] 2. Use the blunt edge of the larger bevel as the molten pool pad. This method follows the same welding method for thin plates. For thin webs with a thickness less than 14mm, the T-joint webs may not be beveled, that is, uniform plate thickness as Weld pool pad; the thickness of the matching wing plate is relatively small, and it is easy to straighten. Generally, there is no assembly gap. When welding, a large current can be used more stably, that is, it can be completely penetrated, and the inclusion of the joint can be affected by the high current. The bottom enters the coating; there is inevitably an assembly gap at the joint of the thick plate workpiece (determined by the characteristics of the thick plate that is difficult to straighten), the groove cutting accuracy is not good (the deviation of the blunt edge is large), and the set large blunt edge and wing The large contact surface of the plate is prone to residue debris and other three reasons lead to an unstable molten pool pad, its uneven thickness, and the existence of uncertain gaps, which make its welding support performance extremely poor

In actual work, no matter how people control it, the actual results are quite different from the expectations. The pass rate of non-destructive testing is extremely low. The main performance is that the root of the weld is not fused, the slag inclusion at the root of the joint, the occlusal slag inclusion of the base metal on the side of the joint, and the edge of the weld surface Undercuts and welds are visibly poor in appearance