%0 Journal Article %A Shi, Deheng %A Zou, Fenghui %A Zhu, Zunlue %A Sun, Jinfeng %D 2018 %I Begell House %K spectral emissivity, emissivity model, oscillation, surface oxidation, heating time, oxide layer %N 15 %P 1445-1458 %R 10.1615/HeatTransRes.2018019355 %T MODELING THE NORMAL SPECTRAL EMISSIVITY OF BRASS H62 AT 800–1100 K DURING OXIDE LAYER GROWTH %U https://www.dl.begellhouse.com/journals/46784ef93dddff27,1cac9afc1a566f6a,40315dda19ff3ddb.html %V 49 %X This work aims to model and predict the normal spectral emissivity of brass H62 at 800–1100 K during the growth of an oxide layer on the surface of specimens. During the experimental period, a specimen was completely exposed to air, so that the oxide layer could grow freely on its surface. The normal spectral emissivity was measured during a 6-h heating period at certain temperatures from 800 to 1100 K in steps of 20 K. The radiance from specimens was measured by an InGaAs detector, which worked at a wavelength of 1.5 μm with a bandwidth of 20 nm. The specimen temperature was measured by averaging the readings of two thermocouples. The observed strong oscillations of the normal spectral emissivity were examined and were confirmed to originate from the interference effect between the radiation from the oxide layer on the specimen surface and the radiation from the substrate. The uncertainties of the normal spectral emissivity and the temperature, to which only the surface oxidation contributed, range approximately from 3.3% to 15.9% and from 3.0 to 11.5 K, respectively. The variation of the normal spectral emissivity with the heating time was evaluated at a certain temperature. The variation of the normal spectral emissivity with the temperature for a given heating time is discussed. A simple functional form is derived which reproduces well the variation of the normal spectral emissivity with the heating time at a given temperature, including the strong oscillations occurring during the initial heating period. %8 2018-07-31