Bartash S. Improvement of technology of mechanized welding in mix of shielding gases steam lines of electric power plants for increase of fieldperformance data.

Research object - process mechanized welding creep resistant Cr-Mo-V steel pearlite mixed shielding gas Ar + CO2. Purpose - to improve technology for mechanized welding steam mixed shielding gas Ar + CO2 to improve the quality characteristics of the structure of welded joints, which increases resource exploitation. Research methods: the use of optical and electron microscopy, and X-ray microprobe analysis, applied mathematics, determining the mechanical properties. Novelty - established that the prolonged use of welded joints steam (> 200 000 hours) of heat-resistant pearlitic steels under creep and low-cycle fatigue damage by weld on the mechanism of pore formation is supplemented by the mechanism of damage to the formation of fatigue cracks; Idea about damageability that occurs in long-term operation weld steam, an association of damage to the structure of the weld and found that the fracture behavior of welded joints under creep and low-cycle fatigue occurs by brittle fracture, which is associated with the restructuring, improved mathematical model of welding heating, heat-resistant pearlitic steels, which allowed us to determine heat input required to produce high quality welds, found that the welding heat input to 1,2 MJ / m gives welds with improved quality characteristics: weld metal is characterized by equiaxed fine grain structure, the area has no large grain fusion and phase; plot overheating is a fine-grained structure of sorbitol or trostita, structure plot incomplete recrystallization presented new products of austenite decomposition in the form trostita, sorbitol or bainite. The results: improved process of mechanized welding creep resistant steels pearlite mixed shielding gas CO2 + Ar, which allows us to obtain a structure with improved properties, set in a protective relationship of the CO2 and Ar, which should be 75% +25%, which provides reduced spatter, refined dependence of sticking to the nozzle spray gun to their heating temperature and the percentage of CO2 + Ar gas mixture, developed and implemented a new design for the welding torch, which is protected by the copyright certificate and the results of the tested and implemented at JSC ZEMI (Kharkiv) TPP (g Serpent), which established the proposed acquisition of the total annual economic impact of 210 thousand UAH. Industry - combined heat and power.