Automated Inclusion Microanalysis in Steel by Computer-Based Scanning Electron Microscopy: Accelerating Voltage, Backscattered Electron Image Quality, and Analysis Time

Dai, Tang; Ferreira, Mauro E.

doi:10.1017/s1431927617012648

Cited by 34 publications

(13 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since the smaller inclusions are below the resolution limit of backscattered electron (BSE) images of polished crosssections, these would not have been detected during automated inclusion analysis. Figure 10 includes (at right) simulated BSE images of inclusion cross-sections, based on the measured spatial resolution of the two SEMs (Tang et al, 2017). The simulated images are consistent with the suggestion that many smaller inclusions would not be detected during automated inclusion analyses.…”

Section: Mechanismsupporting

confidence: 62%

See 1 more Smart Citation

Liquid Inclusion Collision and Agglomeration in Calcium-Treated Aluminum-Killed Steel

2021

Self Cite

View full text Add to dashboard Cite

This work addresses conflicting results in the literature regarding liquid inclusion agglomeration. To assess whether liquid calcium aluminates do agglomerate in liquid steel, laboratory experiments were performed: melting electrolytic iron, deoxidizing the melt with aluminum and subsequently calcium treating the deoxidation products (alumina and magnesia-alumina spinel inclusions). Under laboratory conditions, solid spinels and alumina inclusions were successfully modified, producing a new population of much smaller calcium aluminate inclusions. The new population of inclusions forms because the presence of calcium in the liquid steel destabilizes alumina and MgO-alumina inclusions, which then dissolve into the melt. The liquid inclusions exhibited a weak but statistically significant tendency to agglomerate. Laboratory results were assessed in the light of different collision mechanisms. Agglomeration mainly occurs by Stokes and laminar fluid flow collision when no external stirring is imposed. Monte Carlo simulations of collisions agree reasonably well with experimental results. For industrial conditions, where the liquid steel is agitated by argon bubbling and/or electromagnetic stirring, turbulent collisions dominate.

show abstract

Section: Mechanismsupporting

confidence: 62%

“…INCA Feature software was used with the Quanta 600 for automated inclusion analysis. Detailed explanation of SEM conditions for automated inclusion analysis can be found elsewhere (Tang et al, 2017). The main settings are summarized in Table 1.…”

Section: Methodsmentioning

confidence: 99%

Liquid Inclusion Collision and Agglomeration in Calcium-Treated Aluminum-Killed Steel

2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…Chemical composition, size distribution, and inclusion classification were obtained; with all this information being paramount to evaluate steel cleanliness. 30,31) Pure alumina, spinel, calcium aluminates, and CaO-MgO-Al 2 O 3 -SiO 2 oxide inclusions were defined as Al 2 O 3 based-inclusions and selected to further analyses. diagram using software RStudio v.3.5.1 with ggplot2 and ggtern package.…”

Section: Methodsmentioning

confidence: 99%

Evaluation of Thermodynamic Driving Force and Effective Viscosity of Secondary Steelmaking Slags on the Dissolution of Al<sub>2</sub>O<sub>3</sub>-Based Inclusions from Liquid Steel

et al. 2021

View full text Add to dashboard Cite

Dissolution of Al 2 O 3 -based inclusions are paramount during production of special steel and slag engineering is key to enhance this phenomenon. This work evaluates the influence of thermodynamic driving force (ΔC) and effective viscosity (η e ) on steel cleanliness of three distinct steel grades and slag composition (Steel/Slag A, Steel/Slag B and Steel/Slag C). Initial and final steel and slag samples were withdrawal on an electric steelmaking facility. The first samples after addition of aluminum as deoxidizer and the second after vacuum degassing stage. X-ray fluorescence and optical spectrometry obtained initial and final samples chemical composition. An ASPEX Explorer acquired inclusions data and FactSage v.7.2 performed thermodynamic calculations. Analysis of steel Al and O content highlighted an inefficient dissolution of Al 2 O 3 -based inclusions for Steel/Slag A, deteriorating steel cleanliness. Furthermore, this phenomenon is supported by average inclusions composition on initial and final samples plotted in pseudo-ternary diagram. Steel/Slag B and C provided improved results regarding the dissolution of Al 2 O 3 -based inclusions with a final inclusion density below 0.50 mm -2 . These two slags composition achieved values of ΔC above 25 and η e close to 0.10 Pa•s. In addition, their combined effect (ΔC/η e ) presented values above 250 and had the highest linear fit among these analyses. These properties are influenced by slags chemical composition and can be improved controlling parameters as binary basicity and CaO/Al 2 O 3 ratio. Slags B and C were selected to define an optimal range for these parameters, with binary basicity between 3.00-3.50 and CaO/Al 2 O 3 ratio in a range from 2.50-3.50.

show abstract

“…And in order to obtain a better final product, it is important to evaluate the interactions between the steel and the materials present in the tundish that could lead to the formation of new inclusions by reoxidation. There are automated methods, such as scanning electron microscopy coupled with energy‐dispersive X‐ray spectrometry (SEM/EDS), that are indicated to study these new inclusions . With this analysis, it is possible to obtain the size distribution, chemical composition, and morphology of non‐metallic inclusions.…”

Section: Introductionmentioning

confidence: 99%

“…With this analysis, it is possible to obtain the size distribution, chemical composition, and morphology of non‐metallic inclusions. This information is a paramount for the steel cleanliness analyses and can be used to achieve higher levels of steel cleanliness …”

Section: Introductionmentioning

confidence: 99%

Laboratorial Analysis of Inclusions Formed by Reoxidation in Tundish Steelmaking

Alves

Pereira

Rocha

et al. 2018

steel research int.

View full text Add to dashboard Cite

In order to investigate the formation of inclusions by reoxidation in the tundish, an MgO-CaO gunning mass (GM1), an MgO gunning mass (GM2), a calcium aluminate tundish slag (TS), and a rice husk ash (RHA) silica based are evaluated. The interaction between the steel and these materials is analyzed under laboratory conditions. The experimental results for the chemical composition of steel and the types of inclusions formed satisfactory reach the thermodynamic equilibrium calculated by FactSage. GM1 presents better results for inclusion density and average size of inclusions compared to GM2. The experiment with TS presents a good steel cleanliness despite the formation of numerous alumina inclusions, caused by the reaction between the slag and the alumina crucible. The addition of RHA increases the inclusion density and average size of inclusions, and also the formation of CaO-Al 2 O 3 -SiO 2 oxides inclusions is favored. RHA has harmful effects concerning reoxidation events, deteriorating the good cleanliness obtained with the TS. The experiments with GM1 and TS are less reoxidative and presents a better steel cleanliness. Thus, the usage of this gunning mass and a calcium aluminate slag without RHA is preferable in order to diminish reoxidation during the tundish steelmaking.

show abstract

Automated Inclusion Microanalysis in Steel by Computer-Based Scanning Electron Microscopy: Accelerating Voltage, Backscattered Electron Image Quality, and Analysis Time

Cited by 34 publications

References 12 publications

Liquid Inclusion Collision and Agglomeration in Calcium-Treated Aluminum-Killed Steel

Liquid Inclusion Collision and Agglomeration in Calcium-Treated Aluminum-Killed Steel

Evaluation of Thermodynamic Driving Force and Effective Viscosity of Secondary Steelmaking Slags on the Dissolution of Al<sub>2</sub>O<sub>3</sub>-Based Inclusions from Liquid Steel

Laboratorial Analysis of Inclusions Formed by Reoxidation in Tundish Steelmaking

Contact Info

Product

Resources

About