Actual Problems in Machine Building 2018 Vol. 5 No. 1-2

Актуальные проблемы в машиностроении. Том 5. № 1-2. 2018 Инновационные технологии в машиностроении ____________________________________________________________________ 19 8. Equipment and technologies of air-plasma spraying of functional coatings / V. Kuzmin, I. Gulyaev, D. Sergachev, S. Vaschenko, E. Kornienko, A. Tokarev // MATEC Web of Conferences. – 2017. – Vol. 129. – P. 01052. ANALYSIS OF WELDING EFFICIENCY-SURFACING WORKS IN REPAIR Tokarev A.O. , D.Sc. (Engineering), Associate Professor, e-mail: aot51@ngs.ru Mironenko I.G , D.Sc. (Engineering), Associate Professor, e-mail: mig60@ngs.ru Fedotova E.S. , Post-graduate Student, e-mail: ekaterina-lin@mail.ru Makagon L.D. , Senior Lecturer Siberian State University of Water Transport, 33 Schetinkina st., Novosibirsk, 630099, Russian Federation Abstract Analysis of the causes of breakdowns propeller shaft: assembled by welding, the restored coating is subjected to an accidental arc. It is established that the damage occurred as a result of initiation of cracks with various welding defects: no fusion of the weld with the base metal, craters at the beginning and end of seams, undercuts, ridges, pores, as well as the inconsistency of quality mechanical, thermal processing and others. A contributing factor to the spread of cracks, were: the presence of hardening structures in heat affected zone of the weld, non-metallic inclusions in mostly metal. Proposed measures on prevention of welding defects. Keywords Fatigue destruction, mikrocrack, weld, heat-affected zone microstructure, welding, welding defects, propeller shaft