E-Thesis 348 views 408 downloads
Optimisation of Next Generation Galvanising Pot Hardware / GIOVANNI ALPARONE
Swansea University Author: GIOVANNI ALPARONE
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Copyright: The author, Giovanni Paolo Alparone, 2024 Distributed under the terms of a Creative Commons Attribution 4.0 License (CC BY 4.0).
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DOI (Published version): 10.23889/SUThesis.69771
Abstract
The aim of this research is to study the corrosion behaviour and tribological properties of ceramics for use as roll bearing materials in the zinc bath of continuous galvanising lines.Bulk ceramic materials were investigated, including hexagonal BN, BN Grade M26,Macor®, AlN-BN, Y2O3-ZrO2, Si3N4 and...
| Published: |
Swansea University, Wales, UK
2025
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| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | Ph.D |
| Supervisor: | Penney, D., Sullivan, J., Mills, C., and Edy, J. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa69771 |
| Abstract: |
The aim of this research is to study the corrosion behaviour and tribological properties of ceramics for use as roll bearing materials in the zinc bath of continuous galvanising lines.Bulk ceramic materials were investigated, including hexagonal BN, BN Grade M26,Macor®, AlN-BN, Y2O3-ZrO2, Si3N4 and Al2O3, and their performance was compared to stainless steel 316L and WC-Co coatings. Microscopic examination after static testing in Zn-Al and Zn-Al-Mg found that Zn and Al diffusion occurred in stainless steel, and the thickness of WC-Co coatings was reduced from 150 to around 90 µm. Bulk ceramics, however, were observed to not react with the molten bath. Pin-on-disc testing was conducted on the ceramics and hexagonal BN displayed the lowest coefficient of friction (< 0.1).SiAlON, hexagonal and cubic BN ceramic composites were produced with Field Assisted Sintering Technology by varying the content of BN. Additions of hexagonal BN lubricant did not drastically improve the tribological properties, although static corrosion tests confirmed the corrosion resistance of the ceramic composites to molten Zn-Al and Zn-Al-Mg. Static testing was also conducted on Al2O3 coatings; however, the coatings were prone to damage caused by the large thermal expansion mismatch of 13 × 10−6 K−1 with steel and interactions with the Zn-Al-Mg bath occurred.A bespoke rig enabled dynamic testing of two potential bearing system upgrades. The first upgrade involved replacing Wallex6TM with Wallex4TM and the second upgrade replaced WC-Co with Al2O3 coatings. All the WallexTM grades were similarly corroded, although the diffusion of Zn into the WallexTM alloys was reduced by approximately 60% in the Zn-Al-Mg bath compared to Zn-Al. The wear coefficient k determined that minimal wear damage in both Zn-Al (k = 9.7 × 10−6 K−1 mm3N-1m-1) and Zn-Al-Mg (k =3.6 × 10−6 mm3N-1m-1) was obtained when coupling Al2O3 coatings with Wallex6TM. |
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| Item Description: |
A selection of content is redacted or is partially redacted from this thesis to protect sensitive and personal information. |
| Keywords: |
Continuous Galvanising, Steel, Ceramics |
| College: |
Faculty of Science and Engineering |
| Funders: |
EPSRC, Tata Steel |