Normal Spectral Emissivity of Steel HS2-9-1-8 at 684.5 nm

Abstract

Within this study, the normal spectral emissivity at melting and in the liquid state of the highly alloyed steel HS2-9-1-8 at 684.5 nm is presented. Measurements were performed with a division-of-amplitude photopolarimeter, as part of a fast ohmic pulse heating system reaching heating rates of about 10 8 K · s −1 . The determined data show an increasing emissivity throughout the liquid phase, with the value at liquidus T liquidus = 1687 K being ε = 0.371 and at the highest temperature T max = 2307 K of ε = 0.404. This trend was approximated by a linear least-squares fit yielding ε(T) = 0.282 + 52.88 × 10 −6 T. Although the ε-value at melting is similar to pure iron, the increase in ε with temperature is much higher for HS2-9-1-8 and should be taken into account whenever better accuracies are needed for optical temperature measurements.

Effect of Surface Oxidization on the Normal Spectral Emissivity of Straight Carbon Steel at 800–1100 K in Air

“…8), 10) and 11). As pointed out above, obvious oscillations of normal spectral emissivity appears only at the first several min from the heating start in this work, whereas those reported in the literature 2,[8][9][10][11]14) appeared at very different heating times, typically from several seconds to an hour in the oxidizing surroundings.…”

“…Campo et al 10) observed a number of weak oscillations over the wavelengths ranging from 1.28 to 25 μm at seven different heating times. Wen 11,14) observed few oscillations during the first-hour heating time. Pujana et al…”

“…Several groups of theoretical 9) and experimental work 7,8,[10][11][12][13][14] have sketchily studied the effect of surface oxidization on the spectral emissivity of various steels in the past fifteen years. In detail, Kobayashi et al 7) in 1999 surveyed the time variation in the spectral emissivity of cold-rolled steel surface in the oxidization processes by measuring the spectral emissivity with a sufficiently small time interval.…”

“…Wen et al 11,12) in 2010 studied the spectral emissivity of several kinds of steels, and briefly evaluated the effect of heating time on their spectral emissivity over the wavelengths ranging from 2.91 to 4.13 μm and temperatures of 700, 800 and 900 K. Shortly after, Wen 13) in 2011 reported the spectral emissivity measurements of a variety of steels, and also briefly discussed the effect of heating time on the spectral emissivity of these steels. Reschab et al 14) in 2011 reported the spectral emissivity of highly alloyed steel HS2-9-1-8 at 684.5 nm at melting and in the liquid state. They 14) found out that the variation of spectral emissivity with the temperature was linear.…”

“…Reschab et al 14) in 2011 reported the spectral emissivity of highly alloyed steel HS2-9-1-8 at 684.5 nm at melting and in the liquid state. They 14) found out that the variation of spectral emissivity with the temperature was linear.…”