ON ACCELERATED COOLING MECHANISMS IN THERMAL HARDENING OF ROLLED METAL
https://doi.org/10.17073/0368-0797-2017-12-1005-1007
Abstract
A mechanism is proposed that explains high value of heat transfer coefficient for accelerated cooling of rolled products. At velocities greater than the critical value, the Kelvin-Helmholtz instability arises in nanoscale, which leads to formation of nanodroplets. Cooling is carried out with the help of nanotubes moving through such a vapor film. This allows using the coefficient of heat transfer calculated by the formula in which thermal conductivity of water is taken into account when modeling structural-phase transformations. The second role of nanodrops is to generate a thermal shock, due to which powerful thermoelastic waves are formed. The role of elastic waves is to increase the toughness, since the cracks that appear in the first cooling stage in subsequent sections when the elastic wave interacts with the free shores of the cracks, collapse.
Keywords
accelerated cooling of rolled products,
heat transfer coefficient,
Kelvin-Helmholtz instability,
nanodrops,
thermal shock
Supporting agencies: The work was performed with the partial financial support of the RFBR grant no. 16-48-420530.
About the Authors
V. D. Sarychev
Siberian State Industrial University, Novokuznetsk
Russian Federation
Cand. Sci. (Eng.), Assist. Professor of the Chair of Science named after V.M. Finkel
Russian Federation
Cand. Sci. (Eng.), Assist. Professor of the Chair of Science named after V.M. Finkel
S. A. Nevskii
Siberian State Industrial University, Novokuznetsk
Russian Federation
Cand. Sci. (Eng.), Assist. Professor of the Chair of Science named after V.M. Finkel
Russian Federation
Cand. Sci. (Eng.), Assist. Professor of the Chair of Science named after V.M. Finkel
A. V. Il’yashchenko
Siberian State Industrial University, Novokuznetsk
Russian Federation
Student
Russian Federation
Student
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For citations:
Sarychev V.D., Nevskii S.A., Il’yashchenko A.V. ON ACCELERATED COOLING MECHANISMS IN THERMAL HARDENING OF ROLLED METAL. Izvestiya. Ferrous Metallurgy. 2017;60(12):1005-1007. (In Russ.) https://doi.org/10.17073/0368-0797-2017-12-1005-1007
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