| DOI | Resolve DOI: https://doi.org/10.1016/0257-8972(87)90103-4 |
|---|
| Author | Search for: Dallaire, S.1 |
|---|
| Affiliation | - National Research Council of Canada
|
|---|
| Format | Text, Article |
|---|
| Conference | 14th International Conference on Metallurgical Coatings, March 23-27, 1987, San Diego, CA |
|---|
| Abstract | In high temperature environments graphite has excellent physical properties. However, when it is exposed to oxidizing atmospheres it does not form solid oxides that could provide protection against further attack. Thus, the problem of protecting graphite electrodes against oxidation in air above 1000 °C has not yet been solved satisfactorily.
This paper is concerned with a study to reduce oxidation of graphite electrodes with an inexpensive protective coating. The proposed coating was not designed to be inert to oxygen but to lower the graphite loss noticeably during a steel melting operation. This coating is composed basically of two layers that become modified when the coated graphite part is used. The first layer deposited onto graphite acts as a diffusion barrier for carbon. This layer also has to withstand oxidation because pores within graphite could contain oxygen. The second layer behaves as an oxygen retention material. The plasma spraying technique was deliberately selected to perform the coating. Nevertheless, the process chosen was found to avoid noxious reactions that could occur between the coating components.
Coated graphite samples were first tested at 1600–1700 °C in air under isothermal as well as under cyclic conditions. After it had been exposed for 6 h at 1700 °C, the coating did not spall off and still provided protection to the graphite. Furthermore, industrial graphite electrodes were coated and tested in a steel making plant. The coating was found to reduce the graphite loss significantly. |
|---|
| Publication date | 1987-11-01 |
|---|
| Publisher | Elsevier |
|---|
| In | |
|---|
| Language | English |
|---|
| Peer reviewed | Yes |
|---|
| NRC number | CNRC 26582
NRC-IGM86-301-428 |
|---|
| Export citation | Export as RIS |
|---|
| Report a correction | Report a correction (opens in a new tab) |
|---|
| Record identifier | cb488c8e-a502-485d-8be9-e4a14b9f3841 |
|---|
| Record created | 2020-02-15 |
|---|
| Record modified | 2020-03-17 |
|---|
