A Submerged Arc Welding Process for Welding Steel Plates with a Thickness Greater Than 40mm Without Root Cleaning

Abstract

The invention discloses a submerged-arc welding process for welding a steel plate with a thickness larger than 40mm without back gouging. According to the submerged-arc welding process, the steel plate produced through TMCP or microalloying serves as the base material; the shape of a groove is a double-Y-shaped arc chamfer, one end of the arc is perpendicular to a truncated edge, and the other end of the arc is tangent with a groove edge; the diameter of the matched welding wire is 3.0mm-5.0mm; welding parameters include that weld heat input of a first weld joint on the front surface is 15-25J / cm, weld heat input of a first weld joint on the back surface is 40-50J / cm under the conditions without back gouging, and vertical dislocation of truncated edges of two steel plates is not larger than 1.5mm; other procedures are performed according to the conventional submerged-arc welding mode. By means of the submerged-arc welding process, formation of the weld joints is good, no back gouging on the back surface is needed, time, labor, materials and energy are saved, welding efficiency is increased remarkably, and good economic benefit and social benefit can be created.

Description

technical field [0001] The invention relates to a submerged arc welding process for thick steel plates, in particular to a submerged arc welding process for welding steel plates with a thickness greater than 40mm without root cleaning. Background technique [0002] At present, for the welding of medium and thick plates, before welding the back weld, the welding groove must be cleaned until the front weld is seen (that is, the root of the weld is cleaned), which requires a lot of manpower, material resources and time, and the weld The shape is not very good, the process such as figure 1 shown. In addition to the time and cost of root cleaning, for a weld seam with a plate thickness of 50mm, this welding process needs to increase the weld seam filling by more than 30%. [0003] The applicant also used the double V-groove to carry out the submerged arc welding test without clearing the root. During the test, it was found that the arc of the first weld was easy to deflect, res...

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Problems solved by technology

[0003] The applicant has also used double V-shaped grooves to carry out submerged arc welding tests without cleaning the root. During the test, it was found that the arc of the first weld seam is easy to deflect, resulting in the problem of impenetrable welds.

After analysis, the reasons for the arc deviation are as follows: first, because the end of the welding wire is difficult to touch the tip of the V-shaped groove, the arc start is completed on the side; second, because the welding wire is closer to the side of the groove, the arc is easier to form and stabilized at the shortest thirdly, due to the unavoidable deviation in workpiece assembly and welding wire alignment, and this kind of groove is very sensitive to assembly and alignment accuracy, such as figure 2 shown

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