| 2020 №05 (03) |
DOI of Article 10.37434/tpwj2020.05.04 |
2020 №05 (05) |
The Paton Welding Journal, 2020, #5, 24-28 pages
Improvement of crack resistance of banded support rolls at high-speed surfacing with low energy input
S.V. Shchetynin, V.I. Shchetynina and S.P. Desyatskii
Priazovskyi State Technical University 7 Universitetskaya Str., 87555 Mariupol, Ukraine. E-mail: shchetynin.sergey2012@gmail.com
Abstract
The objective of the work is improvement of deposited metal crack resistance and development of the process of highspeed surfacing of banded support rolls with a low energy input. In order to achieve the set objective, we developed the process of improving the crack resistance due to high-speed surfacing of banded support rolls with a low energy input. In keeping with the equation of heat propagation at high-speed surfacing with a low energy input, increase of deposition rate is accompanied by lowering of the heat input, narrowing of melting isotherm width and HAZ. Calculation and experimental methods were used to establish that at increase of deposition rate, lower heat input results in decrease of deformations and welding stresses, and reduction of the HAZ, where cold cracks form, that prevents delamination of the deposited metal. Melting and solidification rates rise, time of the pool staying in the liquid state is reduced that prevents liquid metal flowing out of the weld pool and improves deposited metal formation. Established regularities were the base for development of the process of high-speed surfacing with low energy input, at which the heat input and welding stresses decrease, HAZ is reduced and deposited metal delamination is prevented, melting and solidification rates increase, time of the pool staying in the liquid state becomes shorter, and crack resistance of banded support rolls becomes higher. Developed process of high-speed surfacing of banded support rolls with a low energy input provides a lowering of the heat input and welding stresses, HAZ reduction, increase of melting and solidification rates and crack resistance, and absence of deposited metal delamination or band failures. 11 Ref., 6 Figures.
Keywords: high-speed surfacing with low energy input, melting isotherms, heat input, welding stresses, HAZ, crack resistance, banded support rolls
Received 24.10.2019
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