Improvement of the technology of welding high-temperature diaphragms in steam turbine flow section

A.K. Tsaryuk, V.Yu. Skulsky, M.A. Nimko, A.N. Gubsky, A.V. Vavilov, A.G. Kantor
2016 The Paton Welding Journal  
Special features and causes for operational damage in welded components of high-temperature diaphragms are considered. Comparative testing was performed of welding-technological properties of some commercially available coated electrode grades for welding heat-resistant steels of Cr-Mo and Cr-Mo-V compositions. Implant procedure and welding of Tekken technological samples were used to assess the delayed fracture susceptibility of 15Kh12VNMF + 15Kh1M1FL steel welded joints at application of
more » ... ted electrodes. It is established that to ensure a high cold cracking resistance of these steel welded joints, it is necessary to apply preheating at 200-250 °C. Proceeding from the data of measurement of metal hardness in welds and HAZ of welded joints and weld metal impact toughness, an optimum mode of heat treatment of 15Kh12VNMF + 15Kh1M1FL steel welded joints was determined. It is shown that a softening zone of lower hardness forms in the HAZ metal structure of 15Kh12VNMF steel, in which the samples fail at testing for static tension at working temperature of 570 °C. 8 Ref., 4 Tables, 10 Figures. K e y w o r d s : arc welding, heat-resistant steels, dissimilar steel welded joints, cold cracks, heat treatment * Based on materials of the work performed under purpose-oriented integrated program of the NAS of Ukraine «Problems of residual life and safe operation of structures, constructions and machines» (2013-2015).
doi:10.15407/tpwj2016.03.05 fatcat:royr6rvcvreczkaq7ooe4zarrm