Reduction of oxides formation at surfact depositsitson of wear-resistant alloys

Abstract

The article deals with the issues of reducing the content of harmful substances when surfacing alloyed wear-resistant alloys. Studies have been carried out to determine the possibility of reducing the formation of oxides during surfacing of high-alloy wear-resistant alloys of the sormite type using a closed filter-ventilation system, which ensures minimal losses of alloying elements during the formation of the deposited layer. The loss of alloying elements during surfacing is influenced by a number of metallurgical and technological factors, including the share of the base metal in the deposited, surfacing modes, oxidation processes during melting of the electrode material and in the melt of the weld pool when interacting with the surrounding gas environment.

To reduce the oxygen content in the gas-air mixture formed during the surfacing process, special absorbent substances are used in a closed filtering and ventilation system, which reduce the course of oxidative processes with the formation of oxides of alloying elements. At the same time, the gas-air mixture is taken from the zone of arc burning and the weld pool, filtered through a system of special filters, in which solid and gaseous components of the welding aerosol are removed, after which the purified gas mixture is used as gas protection during surfacing.

We used powder tapes containing a mechanical mixture of powder components and a complex-alloyed alloy in the core. A complex-alloyed alloy, an alloy previously melted in an induction furnace, containing the necessary alloying elements. Particles of the required sizes were obtained by hydrogranulation, which were then introduced into the core of a flux-cored tape. The indicated flux-cored strips provided the same chemical composition of one alloying system in the deposited layer. After surfacing, the chemical composition of the deposited metal was determined for the content of carbon, manganese, silicon, nickel. The use of a closed filtering and ventilation system makes it possible to reduce the formation of oxides of alloying elements, which requires the determination of specific parameters for each surfacing process. Creation and use of closed fil'tro vent system (CFVS), serve of the filtered air in area of surfacing and providing safe  labour in the workplace of welder. It corresponds the international standard of ISO and norms of European Union. Therefore, to execute a requirement to impermissibility of hit of harmful questions in an atmosphere concordantly  Kiotskomuo and to Parisian protocols.