Keyword: «welding»

Existing technologies for welding polyethylene pipes with embedded heaters allow welding in the ambient air temperature range from -10℃ to 40℃. In this article presents the results of the implementation of the technology developed at the Institute of Oil and Gas Research, Siberian Branch of the Russian Academy of Sciences, which makes it possible to weld polyethylene pipes using fittings with embedded heaters in an extended range of ambient temperatures from -50℃ to 40℃. A description is given of a prototype of a welding machine that allows welding for an extended temperature range. Using the developed software, the device performs the operations of preheating, temperature equalization, reflow and controlled cooling in automatic mode. A description of the technical implementation of the prototype welding machine for low temperatures is given and some test results of specimens welded by the prototype at low temperatures are shown.

The paper substantiates the direction associated with the solution of the interdisciplinary problem of finding ways to improve the reliability and survivability of resource-determining parts and products of equipment operating in the conditions of natural low climatic temperatures of the Northern and Arctic re-gions of the Russian Federation. Prompt provision of services for the repair of worn-out equipment reduces the costs of downtime of production facilities operating in conditions of low climatic temperatures: marine and river marine equipment, port infrastructure, mining, construction and installation, automotive and road construction equipment, pipeline and railway transport. The paper substantiates the need for scientifically based support of the tasks to be solved, not only for the conditions of stationary repair and restoration and welding and assembly complexes of wear-out parts and products of equipment of northern execution, but also for the conditions of their use in mobile complexes.

The paper provides a brief overview of the technological methods studied at the Institute of Physics and Technical of the Siberian Branch of the Russian Academy of Sciences. Impact-mechanical treatment is proposed as one of the promising methods for hardening surfaces and reducing residual welding stresses. The development of fundamental research in the field of development and improvement of technological methods of post-weld processing to improve the physical and mechanical properties of welded joints of metal structures operated at low climatic temperatures is an important area with high opportunities for their intro-duction into production.

The problem of ensuring the reliability and strength of equipment and structures operating at low climatic temperatures is an urgent scientific and technical task today. Ensuring sufficient cold resistance and strength means preventing brittle fracture of structural elements at loads that are significantly lower than the calculated ones. One of these characteristics is impact strength. The paper presents the results of studies of the impact strength of a welded joint of steel 10ХСНД obtained by DC welding and pulsed arc welding.