Welding of ring joints of field pipelines with internal corrosion-resistant surfaced layer

Abstract

The purpose of this work was to study the issues of ensuring the standard quality indicators of installation of welded pipes of field pipelines with a deposited layer of high-chromium steel. The research was performed on pipes made of steel 09G2S of the K48 strength category with a diameter of 258 mm and a wall thickness of 6 mm. The formation of the deposited layer on the inner surface of the pipe ends was performed by electric arc welding in protective gases with a wire SV-12X13 with a diameter of 1.2 mm. Welding of ring joints of pipes was performed with LB-52U type E50A electrodes according to GOST 9467 in accordance with the developed technology. Experimental testing of welding technology with an assessment of the quality of the resulting welds and their corrosion resistance was evaluated using non-destructive and destructive testing methods. Research results have shown the possibility of obtaining a corrosion-resistant welded joint with appropriate quality standards. Regulatory requirements for the welded connection of pipes with an internal surfaced layer were defined, which can be used in the implementation of projects for the construction of field pipelines with this design. It was shown, that to provide normative values of mechanical properties of welded joints of pipes with internal weld layer requires the development of additions to existing welding technology to the preparation of pipes prior to welding and temperature control prior and concomitant heating, to avoid embrittlement of the metal of the root seam layer when its alloying.