METHOD OF AUTOMATIC ARGON-ARC WELDING OF AUSTENITIC STEEL PIPES Russian patent published in 2007 - IPC B23K9/167 B23K9/23 B23K31/02 B23K33/00 B23K101/06 B23K103/04 

FIELD: mechanical engineering; argon-arc welding.

SUBSTANCE: invention relates to methods of automatic argon-arc welding of austenitic steel pipes in manufacture of important constructions, such as high-pressure pipes used at nuclear power stations. Proposed method includes mechanical preparation of welding surface zone, veeing edges to miter of 3.0-3.5 mm and subsequent multiple-pass welding with nonconsumable negative electrode using filler wire. Welding edges are veed to miter of 2.7-3.0 mm. Welding at first pass is carried out with heat input of 0.35-0.55 MJ/m by impulse current. Welding at second pass is done with heat input of 0.6-0.86 MJ/m by impulse current at cross oscillations of electrode. Welding at third and subsequent passes is carried out with heat input of 0.62-1.16 MJ/m by steady current with cross oscillations of electrode.

EFFECT: increased capacity art welding and quality of weld joint owing to reduction of intercrystalline cracking of weld joint.

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