The Role of Selenium on the Formation of Spheroidal Graphite in Cast Iron
Sulfur, an element that belongs to group 16 (chalcogens) of the periodic table, is an excellent promoter of nucleation substrates for graphite in cast iron. In ductile iron, sulfur favors a higher nodule count, which inhibits the risk of carbides and of microporosity. It is reasonable to expect that...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-10-01
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| Series: | Metals |
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| Online Access: | https://www.mdpi.com/2075-4701/11/10/1600 |
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| author | Gorka Alonso Doru Michael Stefanescu Edurne Aguado Ramon Suarez |
| author_facet | Gorka Alonso Doru Michael Stefanescu Edurne Aguado Ramon Suarez |
| author_sort | Gorka Alonso |
| collection | DOAJ |
| description | Sulfur, an element that belongs to group 16 (chalcogens) of the periodic table, is an excellent promoter of nucleation substrates for graphite in cast iron. In ductile iron, sulfur favors a higher nodule count, which inhibits the risk of carbides and of microporosity. It is reasonable to expect that other elements from group 16, such as selenium or tellurium, play similar roles in the nucleation of graphite. The objective of this paper was to investigate the effect of selenium on the process of graphite formation. Thermal analysis cups were poured to evaluate the nodule count and size distribution. Some of the cups were not inoculated, while others were inoculated with a Ce-bearing inoculant, or with the Ce inoculant and additions of Se. Cross-shaped castings were also poured to quantify the microporosity regions by tomography. It appears that selenium additions modify the number and size of graphite particles, as well as the volume of microshrinkage. Direct correlations between these three parameters were found. Advanced Extensive Field Emission Gun Scanning Electron Microscope (FEG-SEM) techniques were used to identify the nature of the main nucleation compounds. Selenides, combined with Mg and rare earths, were observed to serve as nuclei for graphite. Their presence was justified by thermodynamics calculations. |
| first_indexed | 2024-03-10T06:23:22Z |
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| id | doaj.art-c5a54d5e2bcb41d99d7332c4621281af |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-10T06:23:22Z |
| publishDate | 2021-10-01 |
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| spelling | doaj.art-c5a54d5e2bcb41d99d7332c4621281af2023-11-22T19:09:18ZengMDPI AGMetals2075-47012021-10-011110160010.3390/met11101600The Role of Selenium on the Formation of Spheroidal Graphite in Cast IronGorka Alonso0Doru Michael Stefanescu1Edurne Aguado2Ramon Suarez3AZTERLAN, Basque Research and Technology Alliance (BRTA), 48200 Durango, SpainDepartment of Materials Science Engineering, The OHIO State University, Columbus, OH 43210, USAAZTERLAN, Basque Research and Technology Alliance (BRTA), 48200 Durango, SpainAZTERLAN, Basque Research and Technology Alliance (BRTA), 48200 Durango, SpainSulfur, an element that belongs to group 16 (chalcogens) of the periodic table, is an excellent promoter of nucleation substrates for graphite in cast iron. In ductile iron, sulfur favors a higher nodule count, which inhibits the risk of carbides and of microporosity. It is reasonable to expect that other elements from group 16, such as selenium or tellurium, play similar roles in the nucleation of graphite. The objective of this paper was to investigate the effect of selenium on the process of graphite formation. Thermal analysis cups were poured to evaluate the nodule count and size distribution. Some of the cups were not inoculated, while others were inoculated with a Ce-bearing inoculant, or with the Ce inoculant and additions of Se. Cross-shaped castings were also poured to quantify the microporosity regions by tomography. It appears that selenium additions modify the number and size of graphite particles, as well as the volume of microshrinkage. Direct correlations between these three parameters were found. Advanced Extensive Field Emission Gun Scanning Electron Microscope (FEG-SEM) techniques were used to identify the nature of the main nucleation compounds. Selenides, combined with Mg and rare earths, were observed to serve as nuclei for graphite. Their presence was justified by thermodynamics calculations.https://www.mdpi.com/2075-4701/11/10/1600microporositysulfurseleniuminoculantnuclei |
| spellingShingle | Gorka Alonso Doru Michael Stefanescu Edurne Aguado Ramon Suarez The Role of Selenium on the Formation of Spheroidal Graphite in Cast Iron Metals microporosity sulfur selenium inoculant nuclei |
| title | The Role of Selenium on the Formation of Spheroidal Graphite in Cast Iron |
| title_full | The Role of Selenium on the Formation of Spheroidal Graphite in Cast Iron |
| title_fullStr | The Role of Selenium on the Formation of Spheroidal Graphite in Cast Iron |
| title_full_unstemmed | The Role of Selenium on the Formation of Spheroidal Graphite in Cast Iron |
| title_short | The Role of Selenium on the Formation of Spheroidal Graphite in Cast Iron |
| title_sort | role of selenium on the formation of spheroidal graphite in cast iron |
| topic | microporosity sulfur selenium inoculant nuclei |
| url | https://www.mdpi.com/2075-4701/11/10/1600 |
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