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Doustahadi, Ali

University of British Columbia

The microstructure and mechanical properties of hot-rolled steel are influenced by the cooling process on the runout table. Accelerated cooling has become a key technology to improve the properties of hot-rolled steel. In this study, spray cooling was evaluated for bottom cooling in a pilot scale runout table using rollers. Stainless-steel plates were heated up to ~900 ℃, and bottom spray cooling under various testing conditions was applied to the plates, and temperature variations 1mm above the cooling surface were recorded until ~100 ℃. An inverse heat conduction method was applied to temperature measurements to calculate surface heat flux values. Six stationary-plate tests as well as eight moving plate tests were performed, and the effect of flow-rate (between 50-160 ˡ ⁄𝑚𝘪𝘯), water temperature (10-40℃), and plate speed (0.5-1.6 ᵐ⁄s) on heat transfer were evaluated. The effect of using rollers on heat transfer was studied as well. Here, a decrease in heat fluxes in the stagnation zone as well as an increase away from the stagnation zone was observed. Additionally, a comparison between spray cooling and planar cooling was made, and an increase in heat fluxes was observed for spray cooling at steel surface temperature ~400 ℃. Further, a previously developed model for a bottom planar nozzle was upgraded to describe bottom spray cooling results. The model to describe cooling of moving plates needs further upgrades based on additional experimental studies.

Text

2024-05-30

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/88394

Materials Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/