Effect of Method of Silicon Dioxide Nanopowder Introduction into Weld Pool on Wear Resistance and Structure of Low-Alloyed Weld Metal
V. D. Kuznetsov$^{1}$, D. V. Stepanov$^{1}$, V. V. Peremitko$^{2}$, O. L. Kosynska$^{2}$, A. I. Panfilov$^{2}$, I. V. Kolomoyets$^{2}$
$^{1}$National Technical University of Ukraine ‘Igor Sikorsky Kyiv Polytechnic Institute’, 37 Peremohy Ave., UA-03056 Kyiv, Ukraine
$^{2}$Dniprovsk State Technical University, 2 Dniprobudivska Str., UA-51918 Kamianske, Ukraine
Received: 16.07.2019; final version - 22.04.2020. Download: PDF
The effect of the SiO$_2$ nanopowder’s adding into the welding bath on the wear resistance and structure of low-alloyed weld metal is studied. Silicon dioxide is fixed by preliminary spraying onto the surface of the alcohol solution, by applying a mixture of nanopowder with fluxes or a paraffin pencil and SiO$_2$. Hardfacing is carried out on the templates of steel 09Г2С with wires Нп-30ХГСА under flux АН-60 and Св-08Г2С under flux АН-348А. For correct comparison surfacing regime is constant. Test of durability are carried out for friction conditions of metal by metal according to the scheme of shaft-pads. The amount of wear received as a result of test is determined by weighing or measuring of templates before friction process and after it. The dependence of changes nature in the weld metal on the adding method of additional materials is revealed. The most noticeable increasing of hardness is observed with adding of nano-oxide in a mixture with flux АН-60 with spray technology and using the wire Нп-30ХГСА. Templates welded with the same wire with adding of nanopowder fixed with paraffin to weld bath have maximum wear resistance. The efficiency of adding schemes depends on welded metal’s alloying schemes: during hardfacing with wire increasing of hardness and wear resistance is not observed. Adding of silicon nanoxide in mixture with flux causes the formation of a fine structure with ferrite-carbide composition. The combination of ferrite with different morphologies is recorded: there is polygonal ferrite at the borders of grains which grows outrageous ferrite and divergent plates of needle-shaped ferrite. The number of cementitious secretion increases because of adding the silicon dioxide nanopowder in a mixture with paraffin. Proportionality of hardness increasing to grinding of ferrite-carbide structural component and of wear-resistance increasing to number of cementitious secretions is found.
Key words: arc surfacing, deposited nanopowder, variations of schemes, hardness, wear resistance, structural-phase composition of the weld metal.
URL: http://mfint.imp.kiev.ua/en/abstract/v42/i08/1107.html
DOI: https://doi.org/10.15407/mfint.42.08.1107
PACS: 06.60.Vz, 62.20.Qp, 62.23.Pq, 81.20.Vj, 81.40.Pq, 81.65.-b
Citation: V. D. Kuznetsov, D. V. Stepanov, V. V. Peremitko, O. L. Kosynska, A. I. Panfilov, and I. V. Kolomoyets, Effect of Method of Silicon Dioxide Nanopowder Introduction into Weld Pool on Wear Resistance and Structure of Low-Alloyed Weld Metal, Metallofiz. Noveishie Tekhnol., 42, No. 8: 1107—1118 (2020) (in Ukrainian)