Test Background
The AK Middletown 225t ladle slides normally utilize a four-sliding ZIRC composite plate combined with a single-sliding standard plate. To meet the steel mill’s requirement for a 24-heats upper nozzle with a longer service life, and to minimize the number of plates sets required to reduce labor intensity and associated costs, HYRE and Vesuvius applied for high-performance slide testing with an eight-heats service life.
HYRE provided AK Middletown with six sets of test slide gate plate These high-performance slide gate plate were designed with a 77mm aperture. Testing began on March 18, 2015, with the last set concluding on March 26, 2015.
The first set of slide gate plate was installed on the No. 26 ladle and was used five times off the production line. The second through fifth sets of slide plates were installed on the No. 29 ladle, with the second set used five times, and the third, fourth, and fifth sets used six times each. The sixth set of slides was originally scheduled for inspection in the steel mill’s laboratory, but was ultimately used on the No. 24 ladle and was used six times off the production line. The steel mill was quite satisfied with the test plates provided by HYER.Vesuvius
Three sets of test slides were tested on the 21st and 22nd, each lasting six heats. Field test results revealed that after six heats, all three Vesuvius slide plate exhibited significant erosion from the upper and lower plate hole expansions, as well as significant roughening of the cast hole runners, potentially hindering continued use.
Hole expansion of HYRE products：
The original aperture of the slide plate is：77mm
Transverse hole expansion of upper and lower plates：82~86mm Average:84mm
Longitudinal aperture expansion of upper and lower plates：85~90mm Average 87.5mm
Testd plate | heats | Lower or upper plate | lateral expansion (mm) | Longitudinal expansion (mm) |
1# ALECT steel | 5 | Upper plate | 84 | 90 |
Lower plate | 82 | 85 | ||
2# ZUDCT steel | 5 | Upper plate | 86 | 90 |
Lower plate | 86 | 87 | ||
3# ZURST steel | 6 | Upper plate | 83 | 86 |
Lower plate | 86 | 86 | ||
4# ZURST steel | 6 | Upper plate | 85 | 86 |
Lower plate | 84 | 85 | ||
5# ZURST ZUGTT steel | 6 | Upper plate | 83 | 86 |
Lower plate | 84 | 86 | ||
6# AMGCT ZUGTT steel | 6 | Upper plate | 87 | 84 |
Lower plate | 84 | 84 |
- Hole expansion is relatively uniform, slightly elliptical. The amount of hole expansion is also related to slag blowing from the nozzle oxygen pipe.
- Cracks: After use, a small number of radial cracks have developed in the plate holes, and transverse cracks are prone to forming in the lower portion of the plate with large longitudinal dimensions. Otherwise, the plate surface is not severely scratched due to overburning.
- No steel pinching was observed.
- The shroud edge: Strength is somewhat insufficient, becoming jagged after use, making it prone to steel catching. The contact with the shroud is insufficient. Compared to the Vesuvius product, the shroud edge remains intact and significantly stronger than ours. We hope to improve this aspect during expanded testing.
Based on the results of the testing with the two suppliers’ products, the steel mill has agreed to further expand the testing. For details, please see the follow-up report from Mike.
