Kozulin S. Multipass consumable nozzle electroslag welding under repair the unique equipment

Work is devoted to studying of features of formation of metal of a seam at multipass consumable nozzle ESW (MESW CN) in a wide gap medium-carbon steels for the purpose of development of industrial technology of effective repair of through cracks in large steel details of the unique equipment on a place of their operation. Installed cyclical resizing energy core in the molten slag, forms the metal bath, the instantaneous power and the process temperature of the slag bath in the melting of the base metal, which lasts 0.3 - 0.6 s. Established that the required depth of penetration of the base metal is melted and permissible width of the walls in the gap provided at the value of the specific energy of welding within 220 - 340 kJ/cm2. Proposed and tested methods of selecting the basic values of geometrical parameters of the melting zone to within 10%, sufficient for the solution of technological problems by MESW CN. The influence of the shape and location of the seams on their technological strength and proposed a set of measures to prevent hot cracking. As a result of research developed an effective technology for repair through cracks in large steel parts unique equipment at the site of operation using MESW CN and specialized equipment. The technology is introduced at six cement plants at repair of through cracks in bandages rotary kilns. Application of the developed technology at repair of through cracks in bandages rotary kilns allowed to reduce the general time of recovery work by 3 times in comparison with repair by two-arc automatic submerged arc welding.