Submerged arc welding method of plank boards and jointing boards

Abstract

The invention discloses a submerged arc welding method of plank boards and jointing boards, which is characterized in that through steps of reasonable welding material selection, strict pre-welding preparation, scientific pre-welding preheating, welding process and welding technology, the welding quality of submerged arc automatic welding of plank boards with the thickness of 25mm to 45mm is controlled. The pass rate of welding seams by shooting once reaches 100 percent, and welding distortion is controlled ideally. The mechanical property of a welding joint meets standard requirements, and ensures the quality of products.

Description

technical field [0001] The invention relates to a submerged arc welding method, in particular to a submerged arc welding method for splicing thick plates, which can well control the welding deformation of the submerged arc welding of 25 mm to 45 mm thick plates, and belongs to the field of welding technology. Background technique [0002] The thick plate is welded by submerged arc automatic welding, which can not only improve labor efficiency, reduce labor intensity, improve the working environment, save welding materials, but also reduce labor costs. However, the submerged arc automatic welding of thick plates is prone to defects such as pores, cracks, slag inclusions, lack of fusion, and lack of penetration. The most important disadvantage is that the welding deformation is not easy to control, and the main reasons for its welding deformation are: [0003] 1. Due to the high structural rigidity of the large-thickness plate, the cooling rate after welding is fast, and the ...

AI Technical Summary

Problems solved by technology

However, the submerged arc automatic welding of thick plates is prone to defects such as pores, cracks, slag inclusions, lack of fusion, and lack of penetration

The most important disadvantage is that the welding deformation is not easy to control, and the main reasons for its welding deformation are:

[0003] 1. Due to the high rigidity of the structure of the large thickness plate, the cooling rate after welding is fast, and the weld seam is greatly restrained, so the residual stress on the weld seam is also large, which causes large deformation and cannot obtain satisfactory products

[0004] 2. During welding, the welding parameters have a great influence on the performance of the welded joint structure and the formation of defects

[0007] 5. When the thick plate is turned over and welded at the root of the 50° groove, if the arc voltage is too large, most of the heat of the welding arc will be absorbed by the base metal on both sides of the groove, and the bottom will not have enough heat to melt the base material and flux, which is easy to Incomplete fusion, incomplete penetration and slag defects

If the arc voltage is too small, it is easy to produce defects of unfused or broken arc

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