Y-shaped groove back-chipping-free submerged-arc welding technology for moderately thick plate in boiler and pressure container

Abstract

The invention relates to a Y-shaped groove back-chipping-free submerged-arc welding technology for a moderately thick plate in a boiler and a pressure container. The technology comprises the steps that cutting and assembling are carried out before welding, particularly, a Y-shaped groove is cut in a moderately thick plate barrel through machining or flame cutting according to the plate thickness, wherein the groove gap is 0-1 mm, the root face size is 4-6 mm, and the groove angle is (60-80)+/-5 degrees; Y-shaped groove front face submerged-arc welding bottoming is carried out, particularly, submerged-arc welding is directly adopted for carrying out welding on the front face of the Y-shaped groove, and the fusion depth is larger than 1/2 of the root face size in the welding process; the Y-shaped groove front face submerged-arc welding filling and facing are carried out, particularly, conventional current submerged-arc welding is used for carrying out repeated welding on the front face of the Y-shaped groove for groove front face filling and facing; and Y-shaped groove back face submerged-arc welding is carried out, particularly, submerged-arc welding is directly adopted for carrying out welding on the back face of the Y-shaped groove under the condition that back chipping is not carried out, and selection of welding parameters pays attention to control over the Y-shaped groove back face seam surplus height.

Description

technical field [0001] The invention relates to a welding process for a longitudinal circumferential seam of a medium-thick plate cylinder, in particular to a submerged arc welding process in which the longitudinal circumferential seam of a medium-thick plate cylinder of a boiler and a pressure vessel is unclear, and belongs to the field of welding technology. Background technique [0002] In the field of boilers and pressure vessels, the welding of the longitudinal circumferential seam of the medium-thick plate cylinder is an important part of product manufacturing. The traditional welding method of the medium-thick plate cylinder generally adopts the following two processes: 1) Open Y-type (or X-type ) groove, the front of the groove is welded by submerged arc welding, and the back of the groove is welded by carbon arc gouging and grinding. High; 2) Open Y-shaped (or X-shaped) grooves, the front of the grooves is welded by electrode arc welding or semi-automatic gas shield...

AI Technical Summary

Problems solved by technology

[0002] In the field of boilers and pressure vessels, the welding of the longitudinal circumferential seam of the medium-thick plate cylinder is an important part of product manufacturing. The traditional welding method of the medium-thick plate cylinder generally adopts the following two processes: 1) Open Y-type (or X-type ) groove, the front of the groove is welded by submerged arc welding, and the back of the groove is welded by carbon arc gouging and grinding. High; 2) Open Y-shaped (or X-shaped) grooves, the front of the grooves is welded b...

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