The Effect of Electroslag Remelting on the Microstructure and Mechanical Properties of CrNiMoWMnV Ultrahigh-Strength Steels
The effect of electroslag remelting (ESR) with CaF<sub>2</sub>-based synthetic slag on the microstructure and mechanical properties of three as-quenched martensitic/martensitic-bainitic ultrahigh-strength steels with tensile strengths in the range of 1250−2000 MPa was investiga...
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| Format: | Article |
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MDPI AG
2020-02-01
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| Series: | Metals |
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| Online Access: | https://www.mdpi.com/2075-4701/10/2/262 |
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| author | Mohammed Ali David Porter Jukka Kömi Mamdouh Eissa Hoda El Faramawy Taha Mattar |
| author_facet | Mohammed Ali David Porter Jukka Kömi Mamdouh Eissa Hoda El Faramawy Taha Mattar |
| author_sort | Mohammed Ali |
| collection | DOAJ |
| description | The effect of electroslag remelting (ESR) with CaF<sub>2</sub>-based synthetic slag on the microstructure and mechanical properties of three as-quenched martensitic/martensitic-bainitic ultrahigh-strength steels with tensile strengths in the range of 1250−2000 MPa was investigated. Ingots were produced both without ESR, using induction furnace melting and casting, and with subsequent ESR. The cast ingots were forged at temperatures between 1100 and 950 °C and air cooled. Final microstructures were investigated using laser scanning confocal microscopy, field emission scanning electron microscopy, electron backscatter diffraction, electron probe microanalysis, X-ray diffraction, color etching, and micro-hardness measurements. Mechanical properties were investigated through measurement of hardness, tensile properties and Charpy-V impact toughness. The microstructures of the investigated steels were mainly auto-tempered martensite in addition to small fractions of retained austenite and bainite. Due to the consequences of subtle modifications in chemical composition, ESR had a considerable impact on the final microstructural features: Prior austenite grain, effective martensite grain, and lath sizes were refined by up to 52%, 38%, and 28%, respectively. Moreover, the 95th percentiles in the cumulative size distribution of the precipitates decreased by up to 18%. However, ESR had little, if any, the effect on microsegregation. The variable effects of ESR on mechanical properties and how they depend on the initial steel composition are discussed. |
| first_indexed | 2024-12-11T23:06:03Z |
| format | Article |
| id | doaj.art-7d94f85ee36f4caf99fd0210788af419 |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-12-11T23:06:03Z |
| publishDate | 2020-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Metals |
| spelling | doaj.art-7d94f85ee36f4caf99fd0210788af4192022-12-22T00:46:56ZengMDPI AGMetals2075-47012020-02-0110226210.3390/met10020262met10020262The Effect of Electroslag Remelting on the Microstructure and Mechanical Properties of CrNiMoWMnV Ultrahigh-Strength SteelsMohammed Ali0David Porter1Jukka Kömi2Mamdouh Eissa3Hoda El Faramawy4Taha Mattar5Materials and Mechanical Engineering, Centre for Advanced Steels Research, University of Oulu, P.O. Box 4200, 90014 Oulu, FinlandMaterials and Mechanical Engineering, Centre for Advanced Steels Research, University of Oulu, P.O. Box 4200, 90014 Oulu, FinlandMaterials and Mechanical Engineering, Centre for Advanced Steels Research, University of Oulu, P.O. Box 4200, 90014 Oulu, FinlandSteel Technology Department, Central Metallurgical Research and Development Institute (CMRDI), Helwan, Cairo 11421, EgyptSteel Technology Department, Central Metallurgical Research and Development Institute (CMRDI), Helwan, Cairo 11421, EgyptSteel Technology Department, Central Metallurgical Research and Development Institute (CMRDI), Helwan, Cairo 11421, EgyptThe effect of electroslag remelting (ESR) with CaF<sub>2</sub>-based synthetic slag on the microstructure and mechanical properties of three as-quenched martensitic/martensitic-bainitic ultrahigh-strength steels with tensile strengths in the range of 1250−2000 MPa was investigated. Ingots were produced both without ESR, using induction furnace melting and casting, and with subsequent ESR. The cast ingots were forged at temperatures between 1100 and 950 °C and air cooled. Final microstructures were investigated using laser scanning confocal microscopy, field emission scanning electron microscopy, electron backscatter diffraction, electron probe microanalysis, X-ray diffraction, color etching, and micro-hardness measurements. Mechanical properties were investigated through measurement of hardness, tensile properties and Charpy-V impact toughness. The microstructures of the investigated steels were mainly auto-tempered martensite in addition to small fractions of retained austenite and bainite. Due to the consequences of subtle modifications in chemical composition, ESR had a considerable impact on the final microstructural features: Prior austenite grain, effective martensite grain, and lath sizes were refined by up to 52%, 38%, and 28%, respectively. Moreover, the 95th percentiles in the cumulative size distribution of the precipitates decreased by up to 18%. However, ESR had little, if any, the effect on microsegregation. The variable effects of ESR on mechanical properties and how they depend on the initial steel composition are discussed.https://www.mdpi.com/2075-4701/10/2/262ultrahigh-strength steelelectroslag remeltingmicrostructureprecipitatesmicrosegregationmechanical properties |
| spellingShingle | Mohammed Ali David Porter Jukka Kömi Mamdouh Eissa Hoda El Faramawy Taha Mattar The Effect of Electroslag Remelting on the Microstructure and Mechanical Properties of CrNiMoWMnV Ultrahigh-Strength Steels Metals ultrahigh-strength steel electroslag remelting microstructure precipitates microsegregation mechanical properties |
| title | The Effect of Electroslag Remelting on the Microstructure and Mechanical Properties of CrNiMoWMnV Ultrahigh-Strength Steels |
| title_full | The Effect of Electroslag Remelting on the Microstructure and Mechanical Properties of CrNiMoWMnV Ultrahigh-Strength Steels |
| title_fullStr | The Effect of Electroslag Remelting on the Microstructure and Mechanical Properties of CrNiMoWMnV Ultrahigh-Strength Steels |
| title_full_unstemmed | The Effect of Electroslag Remelting on the Microstructure and Mechanical Properties of CrNiMoWMnV Ultrahigh-Strength Steels |
| title_short | The Effect of Electroslag Remelting on the Microstructure and Mechanical Properties of CrNiMoWMnV Ultrahigh-Strength Steels |
| title_sort | effect of electroslag remelting on the microstructure and mechanical properties of crnimowmnv ultrahigh strength steels |
| topic | ultrahigh-strength steel electroslag remelting microstructure precipitates microsegregation mechanical properties |
| url | https://www.mdpi.com/2075-4701/10/2/262 |
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