In Situ and Real-Time Mold Flux Analysis Using a High-Temperature Fiber-Optic Raman Sensor for Steel Manufacturing Applications

Abstract

Continuous casting in steel production uses specially developed oxyfluoride glasses (mold fluxes) to lubricate a mold and control the solidification of the steel in the mold. The composition of the flux impacts properties, including basicity, viscosity, and crystallization rate, all of which affect the stability of the casting process and the quality of the solidified steel. However, mold fluxes interact with steel during the casting process, resulting in flux chemistry changes that must be considered in the flux design. Currently, the chemical composition of mold flux must be determined by extracting flux samples from the mold during casting and then processing these samples offline to estimate the working chemical composition and, therefore, the expected properties of the flux. Raman spectroscopy offers an alternative method for performing flux analysis with the potential to perform measurements online during the casting process. Raman spectroscopy uniquely identifies specific chemical bonds and symmetries in the glassy flux by revealing peaks that are a fingerprint of the vibration modes of molecules in the flux. The intensities of specific peaks in Raman spectra can be correlated with the chemical composition of the melt and associated properties such as basicity and viscosity. This paper reports on the first use of a portable fiber-optic Raman sensor for in situ Raman spectroscopic measurements of molten flux at 1400 °C. The work demonstrates the advantages of fiber-optic Raman spectroscopy to document the structure and chemical composition of flux samples at temperatures typically encountered in the mold during continuous caster operation. Experimental results demonstrate that the composition-dependent Raman signal shifts can be detected at caster operating temperatures, and the use of hightemperature Raman analysis for in-line flux monitoring shows significant promise for the in situ detection of changes in flux composition and physical properties during casting.

Structural analysis of molten materials by a remote fiber optic Raman sensor

“…Therefore, by examining all Raman spectra at the same temperature, the intrinsic temperature dependence of Raman scattering can be eliminated. In our previous studies, we proposed a background subtraction method to eliminate the background thermal radiation signal [15,16]. In the high-temperature experiments, an empty furnace was first heated to 1400 °C and held for thermal stability.…”

“…Comparing with the traditional electronic devices, Fiber optic sensors offer numerous advantages over traditional sensors, including high sensitivity, immunity to electromagnetic interference, and the ability to operate in harsh environments [9][10][11][12][13][14]. Recent advancements in fiber optic sensors Raman spectroscopy have opened up new avenues for studying the molecular structure of molten materials [15,16]. Raman spectroscopy is a non-destructive analytical technique that can be used to identify the molecular structure of a material by analyzing the scattering of laser light.…”

Enhancing aluminum casting efficiency through real-time optical fiber sensor monitoring at the metal-mold interface

“…Fiber-optic sensors have become increasingly popular in various industries due to their exceptional sensitivity and selectivity, utilizing light to detect environmental changes. They find applications in civil structures, biomedical, environmental monitoring, security, and steel industries [5][6][7][8][9][10][11]. Their ability to operate reliably in harsh environments is a significant advantage, as they can withstand extreme temperatures, radiation, and high pressures.…”

Effects of Pb nanosheets substrates on the optical and electrical properties CrSe thin films

“…This feature makes the use of CrSe in high k optoelectronics hardly possible. In addition as the properties of chromium selenide are highly influenced by the growth method and substrate type there is a need to use time resolved in situ monitoring systems like x-ray diffraction, scanning electron microscopy, time-Resolved Raman/ Infrared spectroscopy and differential scanning calorimeter to visualize the phase formation [14][15][16].…”