The Paton Welding Journal, 2021, #10, 33-37 pages
Electroslag technologies for repair of through-thickness cracks in thick parts
S.M. Kozulin1, I.I. Lychko1 and H.S. Podyma2
E.O. Paton Electric Welding Institute of the NAS of Ukraine
11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine. E-mail: email@example.com
National Technical University of Ukraine «Igor Sikorsky Kyiv Polytechnic Institute»
6/2 Dashavska Str., 03056, Kyiv, Ukraine
Results of investigations are presented, which were performed in order to develop a highly-productive technology for repair of
through-thickness cracks in thick parts in their operation site. The aim of the work is to study and establish the main principles
of a high-efficient technology of repairing defects of the type of through-thickness cracks in thick parts in their operation site
by the method of consumable nozzle multipass electroslag welding. The main tasks of the study were selection of principal
diagram of electroslag welding, development of a procedure for calculation of geometrical parameters of edge preparation,
that the most fully meet the conditions for formation of sound metal of the welded joint in a wide gap, development of basic
principles of the technique of making welds and creation of routing technology of repair. Performed studies were the base for
development of decision taking algorithms and general principles of the technology for repair of large-sized parts of unique
equipment in its operation site, using the proposed method. Technological recommendations for repair of through-thickness
cracks in such parts are based on the following postulates, elaborated proceeding from the features of the proposed method: domain
of rational values of welding specific energy, providing sound weld formation, techniques allowing hot crack prevention
in the weld central parts, conditions of minimizing the welding stresses when welding rigid joints, conditions of controlling the
weld chemical composition that provide reduction of the fraction of base metal participation in weld formation, and lowering
of harmful impurities level in it, and recommendations on selection of electrode and auxiliary materials, etc. Technological
recommendations were successfully tried out in six cement works at repair of through-thickness cracks in rotary kiln tires.
multipass electroslag welding, consumable nozzle, through-thickness cracks, repair, specific heat input, hot
cracks, welding voltages, decision taking algorithm, technology recommendations
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