These proceedings of the International Conference ‘Welding in Russia 2019: State-of-the-Art and Perspectives’, which was held from 3 to 7 September 2019 in Tomsk (Russia), are generalization of the presented and discussed achievements as well as problems in this area of science. It was the first large-scale meeting in the post-Soviet region covering all parts of welding production including international cooperation aimed at strengthening ties between leading scientists and specialists. Representatives of large corporations and industrial associations, scientific and educational institutions took part in the Conference. Many important issues were discussed: new materials and equipment for welding; repair of critical structures operated under extreme conditions, their reliability, reducing risks of man-made accidents as well as negative impact on the environment.Welding, as the main technological process for production of metal structures for various industrial purposes, is a multi-disciplinary science covering a wide range of subjects such as materials science, physics, mathematics, chemistry, electrical and computer engineering. Its development requires the results of numerous investigations because the main drawback affecting the performance of the welded structure is application of materials that do not meet operation conditions, ineffective technologies for their joining or incorrect parameters of welding modes. As a result, various micro- and macro-discontinuities, stresses and deformations are formed in welds. This contributes to different problems such as low strength and corrosion resistance, brittle fracture under load (especially at low temperatures), etc. Therefore, special attention should be paid to heat input control during welding. This may significantly improve quality of welded joints. In order to develop knowledge about the listed welding features, the following sections are presented in the proceedings:New materials for production and repair of critical structures and special-purpose equipment operated under extreme loads and low climatic temperatures of the Far North and the Arctic.Directions and trends in application of conventional heat sources (electric arc, plasma, etc.) as well as high-performance ones (laser and electron beams) significantly expanding the boundaries of physical capabilities to control processing of metals and alloys, stresses and deformations formed in complex-shaped products.Welding and technological properties of materials and equipment: registration methods, assessment of reliability, expert assessment.Reliability of critical structures, reducing risks from industrial accidents, as well as negative environmental impacts.The presented papers may be interesting to a wide range of specialists in the fields of materials science, hydrodynamics, chemistry and mechanics of solids, reliability and technogenic safety, welding control in the manufacture of structures for critical purposes.The Editor of the Proceedings,Professor, Doctor of Technical Science, Yuriy SaraevInstitute of Strength Physics and Materials Science, Siberian Branch, Russian Academy of ScienceTomsk, Russialitsin@ispms.tsc.ru