Ударна в’язкість при односторонньому високошвидкісному зварюванні труб для газо- і нафтопровідних магістралей

Abstract

One-sided high-speed pipes welding for gas and oil pipelines, which are made of 10G2S1, 09G2S high-strength steels and are operated at high pressures and low temperatures, is limited with the difficulties to ensure the process stability, the welded joints and impact toughness. Therefore, the process development of one-sided high-speed pipes welding for gas and oil pipelines, which provides increase in the arc self-regulation, in the process stability, in the welded joints quality and in the impact toughness, is an important scientific and technical problem. An effective way to increase the welded joints impact toughness is high-speed welding at low heat input, which secures decrease in heat input into the base metal and in welding stresses, increase in the crystallization rate of the weld pool liquid metal and interatomic bonds, the microstructure refinement, the interatomic distance reduction. Energy minimum ensures process stability and welded joints impact toughness maximum. It has been found that at argon-arc welding, the static and the arc energy characteristics change, the near-electrode voltage drops sum decreases, as well as the arc column potential gradient, arc voltage, heat input, welding stresses, the interatomic distance; while interatomic bonds, arc self-regulation, stability process and welded joints impact toughness increase; the microstructure is refined. Argon-arc one-sided high-speed pipes welding for gas and oil pipelines process has been developed, which due to argon use, provides decrease in near-electrode voltage drops sum, in potential gradient and arc voltage, in heat inputand heat energy, ensures welding stresses reduction, and welding baths liquid metal crystallization rate increase, microstructure grinding, increase in arc self-regulation, process stability, the quality increase as well as increase in welded joints impact toughness by 2-2,5 times