Effect of austempering temperature on microstructure and mechanical properties of ductile cast iron modified by niobium
Owing to their exceptional physical, mechanical, and technological properties, ductile cast irons have been increasingly used, especially in automotive industries. Alloying elements and heat treatment routes can increase the strength of ductile irons. In this work, the effects of austempering temper...
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Elsevier
2021-05-01
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| Series: | Journal of Materials Research and Technology |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785421003859 |
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| author | Wilson Sckudlarek Manar N. Krmasha Kassim S. Al-Rubaie Orlando Preti Julio C.G. Milan Cesar E. da Costa |
| author_facet | Wilson Sckudlarek Manar N. Krmasha Kassim S. Al-Rubaie Orlando Preti Julio C.G. Milan Cesar E. da Costa |
| author_sort | Wilson Sckudlarek |
| collection | DOAJ |
| description | Owing to their exceptional physical, mechanical, and technological properties, ductile cast irons have been increasingly used, especially in automotive industries. Alloying elements and heat treatment routes can increase the strength of ductile irons. In this work, the effects of austempering temperature and time on the microstructure and mechanical properties of a ductile cast iron modified by 0.35% Nb have been studied. Two austempering temperatures of 320 °C and 360 °C for a holding time of 15, 30, 60, and 90 min were applied. The niobium addition was found to be effective in homogenizing the size and distribution of graphite nodules, maintaining the degree of nodularization above 90%, favoring pearlite refining, increasing the volume fraction of pearlite, forming niobium carbides in dispersed blocks in the matrix and graphite nodules, increasing both the yield and tensile strength, and reducing the elongation. Both the niobium addition and austempering temperature improved the yield and tensile strength but decreased the elongation compared to those of the reference ductile iron. The best combination of strength and ductility was observed at an austempering time of 60 min. The effect of austempering temperature on the microstructure and tensile mechanical properties of tested irons was found to be crucial. |
| first_indexed | 2024-12-17T07:22:34Z |
| format | Article |
| id | doaj.art-757eda953f4249958e671a750663fa97 |
| institution | Directory Open Access Journal |
| issn | 2238-7854 |
| language | English |
| last_indexed | 2024-12-17T07:22:34Z |
| publishDate | 2021-05-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Materials Research and Technology |
| spelling | doaj.art-757eda953f4249958e671a750663fa972022-12-21T21:58:43ZengElsevierJournal of Materials Research and Technology2238-78542021-05-011224142425Effect of austempering temperature on microstructure and mechanical properties of ductile cast iron modified by niobiumWilson Sckudlarek0Manar N. Krmasha1Kassim S. Al-Rubaie2Orlando Preti3Julio C.G. Milan4Cesar E. da Costa5Universidade Do Estado de Santa Catarina - UDESC, R. Paulo Malschitzki 200, Joinville, SC, 89219-710, BrazilMechanical Engineering, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4L7, CanadaMechanical Engineering, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4L7, Canada; Corresponding author.Sociedade Educacional de Santa Catariana, Rua Albano Schmidt 3333, Boa Vista, Joinville, SC, BrazilUniversidade Do Estado de Santa Catarina - UDESC, R. Paulo Malschitzki 200, Joinville, SC, 89219-710, BrazilUniversidade Do Estado de Santa Catarina - UDESC, R. Paulo Malschitzki 200, Joinville, SC, 89219-710, BrazilOwing to their exceptional physical, mechanical, and technological properties, ductile cast irons have been increasingly used, especially in automotive industries. Alloying elements and heat treatment routes can increase the strength of ductile irons. In this work, the effects of austempering temperature and time on the microstructure and mechanical properties of a ductile cast iron modified by 0.35% Nb have been studied. Two austempering temperatures of 320 °C and 360 °C for a holding time of 15, 30, 60, and 90 min were applied. The niobium addition was found to be effective in homogenizing the size and distribution of graphite nodules, maintaining the degree of nodularization above 90%, favoring pearlite refining, increasing the volume fraction of pearlite, forming niobium carbides in dispersed blocks in the matrix and graphite nodules, increasing both the yield and tensile strength, and reducing the elongation. Both the niobium addition and austempering temperature improved the yield and tensile strength but decreased the elongation compared to those of the reference ductile iron. The best combination of strength and ductility was observed at an austempering time of 60 min. The effect of austempering temperature on the microstructure and tensile mechanical properties of tested irons was found to be crucial.http://www.sciencedirect.com/science/article/pii/S2238785421003859Austempered ductile ironNiobium carbideAustempering temperatureAustempering timeMicrostructureMechanical properties |
| spellingShingle | Wilson Sckudlarek Manar N. Krmasha Kassim S. Al-Rubaie Orlando Preti Julio C.G. Milan Cesar E. da Costa Effect of austempering temperature on microstructure and mechanical properties of ductile cast iron modified by niobium Journal of Materials Research and Technology Austempered ductile iron Niobium carbide Austempering temperature Austempering time Microstructure Mechanical properties |
| title | Effect of austempering temperature on microstructure and mechanical properties of ductile cast iron modified by niobium |
| title_full | Effect of austempering temperature on microstructure and mechanical properties of ductile cast iron modified by niobium |
| title_fullStr | Effect of austempering temperature on microstructure and mechanical properties of ductile cast iron modified by niobium |
| title_full_unstemmed | Effect of austempering temperature on microstructure and mechanical properties of ductile cast iron modified by niobium |
| title_short | Effect of austempering temperature on microstructure and mechanical properties of ductile cast iron modified by niobium |
| title_sort | effect of austempering temperature on microstructure and mechanical properties of ductile cast iron modified by niobium |
| topic | Austempered ductile iron Niobium carbide Austempering temperature Austempering time Microstructure Mechanical properties |
| url | http://www.sciencedirect.com/science/article/pii/S2238785421003859 |
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