Unclear root welding method for thick plate Y-groove with unequal gap

Abstract

The invention discloses an unequal-gap non-back-gouging welding method of Y-type beveled edges of thick plates. The method includes the steps of (1) cutting and assembling before welding, (2) front face bottoming welding, (3) front face small-current submerged-arc welding, (4) front face filling and cosmetic welding and (5) back face large-current submerged-arc welding, wherein in the first step, steel plates are cut to form beveled edges, and the Y-type beveled edges are formed through unequal-gap assembly; in the second step, gas shielded welding is utilized, and swing welding is performed through solid welding wires; in the third step, a small current makes the submerged-arc welding not burn through the bottoming welding; in the fourth step, a plurality of streaks of welding is performed on the front faces with the conventional current submerged-arc welding to perform front face filling and facing; in the fifth step, under the condition that carbon back gouging is not performed, a large current is directly utilized to perform submerged-arc welding on the back faces, and the large current makes the fusion depth of the back face submerged-arc welding larger than the size of truncated edges of the Y-type beveled edges.

Description

technical field [0001] The present invention relates to steel structure manufacturing technology, and more particularly, to thick plate welding technology. Background technique [0002] Thick plate butt tailor welding is an important link in the manufacture of steel structure products. The traditional thick plate welding method generally adopts V-shaped (or X-shaped) grooves, front welding, carbon planing on the back, and then welding, and its production efficiency is low. , high energy consumption, serious environmental pollution, and a large amount of weld metal filling, high welding cost, so it is urgent to develop a new method of efficient thick plate unclear root welding. [0003] The traditional V-shaped (or X-shaped) groove with unclear root submerged arc welding technology is front submerged arc welding, and the back is not carbon planed after turning over, and submerged arc welding is directly used. This method has great impact on the quality of groove processing an...

AI Technical Summary

Problems solved by technology

At the production site, flame-cut grooves are usually used for thick plates. The quality of the grooves is poor, the straightness is not high, and the gap after the steel plates are assembled is not uniform. Various defects such as inclusions and lack of fusion

[0004] At present, I-type groove with unequal gap and unclear root welding technology is widely used in steel plates with a thickness of less than 16 mm. However, when the thickness of the plate is further increased, it is impossible to realize the front and back weld metal by simply increasing the submerged arc welding current. good fusion between

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