Gouging-less complete penetration welding method, and welded joint

Abstract

In single bevel groove or double bevel groove welding, an initial welding bead (21) is formed between a first steel plate (11) and a second steel plate (12) using an initial welding bead welding current of 130 to 300 A, while a weaving action is repeatedly carried out by moving a welding torch (31) forward in a direction of welding progress to a second steel plate (12) weaving end (P2), and then moving the welding torch (31) backward with respect to the direction of welding progress from said weaving end (P2) to a first steel plate (11) weaving end (P1), after which single-layer welding is performed from the front side, and in addition single-layer or multilayer welding is performed on the reverse side using a reverse-side welding current of 280 to 450 A. In this way, the present inventionprovides a gouging-less complete penetration welding method and a welded joint with which welding defects are suppressed, even in cases in which there is a wide a root gap, assembly accuracy is poor,or the root gap is non-uniform, and which can be applied to semi-automatic welding and automatic welding of both single bevel grooves and double bevel grooves.

Description

technical field [0001] The invention relates to a root cleaning-free full-penetration welding method and a welded joint for welding a レ-shaped groove or a K-shaped groove without root cleaning. Background technique [0002] Conventionally, in the full penetration welding of レ-type groove joints and K-type groove joints that do not use a liner method, after welding the first layer, the first layer and Clean the welding defects that occur in the first layer (shoveling, clearing the root), arrange the welding place (groove) to the best state, and then weld again. [0003] However, full-penetration welding for backrooting has poor work efficiency compared with welding by the pad method, and high skill and experience are required for rooting and rewelding. In addition, the accuracy of rooting (depth and surface shape) is unstable, and when the root gap is wide due to low assembly accuracy, the back surface is likely to fall off, so there are problems such as welding defects and ...

AI Technical Summary

Problems solved by technology

[0010] However, according to Patent Document 1, the welding conditions are limited, and it cannot be dealt with when the root gap is empty or uneven, and there is a possibility of voids due to falling off.

In addition, the problem of difficulty in setting the target position of the back surface that occurs when welding with a welding robot has not been solved

[0011] In addition, according to Patent Document 2, it cannot be applied to レ-shaped grooves, etc., and the degree of freedom for the groove shape is low, and there is still room for improvement.

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