NIST Standard Reference Database 30
Last Update to Data Content: 2002
"Analysis of Candidate Silicon Carbide Recuperator Materials Exposed to Industrial Furnace Environments," J.J. Federer, T.N. Tiegs, D.M. Kotchick, and D. Petrak, ORNL Report Number: ORNL/TM-9677, pp. 1-61 (1985), published by Oak Ridge National Laboratory.Language: English
"The...materials (were)...commercially available SiC ceramics....The specimens were mostly tubes measuring nominally 25mm or 89 mm outer diameter (1 or 3.5 in.) and 25cm to 30 cm long (10 to 12 in.). ... The corrosion testing program involved installation of tubular specimens... in... industrial furnaces for exposure to high temperature combustion environments. Although all furnaces burned natural gas, the composition of the flue gases depended on the type of furnace operation... and, possibly, on specific location within the flue. The exposures occurred during typical furnace operations involving feed materials, heating and cooling cycles, maximum temperatures, fluxes, and air-fuel mixtures. The aluminum remelt furnaces were charged with NaCl-KC1-Na3AlF6 flux along with metal to be melted. In addition, the molten aluminum in furnace No. 2 was sparged with chlorine gas during a portion of each normal cycle. ... Steel billets in the soaking pits were covered with topping compounds, which is standard industry practice to minimize oxidation. Although flue gases in the furnaces were not analyzed, analysis of material that deposited on some specimens revealed significant quantities of metals. Gaseous species in the fuel combustion products... included N2, O2, CO2, and H2O."
"The outer diameters of exposed specimens were measured to determine changes indicative of corrosion. Measurements were made with a micrometer on apparently clean specimens, i.e., those from the forge, steel reheat, and steel soaking pit furnaces. Specimens from the aluminum remelt furnaces ... had deposits on the surfaces, which required that their diameters be measured with a microscope on samples prepared for ceramographic examination. In either case, three or four measurements were made at approximately equal intervals around the circumference."C-ring test
"C-ring specimens cut from tubes... Tubes were cut into 5 mm wide rings using a cutoff wheel impregnated with 75 µm diamonds. C-rings were made by cutting approximately 5 mm long arcs from the rings. The final thickness of the rings was obtained by grinding both sides with 75 µm diamond abrasive. The outer edges of specimens were beveled with a 30 µm diamond lapping wheel. The specimens were loaded so that a tensile stress was applied to the outer surface at a point opposite the open part of the ring. Specimens were heated to 1100 °C in air, then the loading ram was advanced at 8.5 µm/s ... until fracture occurred."
| Amount of Element ( formula units ) |
Element ( no unit ) |
|---|---|
| 1 | Si |
| 1 | C |
| Exposure Time ( h ) |
Maximum Temperature ( °C ) |
Furnace |
Corrosion Rate ( mg cm-2 h-1 ) |
|---|---|---|---|
| 5545 | 1040 | Al Remelt1 | - 36 |
| 4440 | 1175 | Forge | + 7 |
| 1455 | 1100 | Reheat | - 7 |
| 2280 | 925 | Soak Pit 1 | - 7 |
| 3460 | 1250 | Soak Pit 2 | -468 |
Surface recession rates were converted to corrosion rates.
| C-ring Test Temperature ( °C ) |
Pre-Test Furnace |
Flexural Strength ( MPa ) |
|---|---|---|
| 1100 | Al Remelt1 | 204 |
| 1100 | Forge | 238 |
| 1100 | Reheat | 231 |
| 1100 | Soak Pit1 | 233 |
| Amount of Element ( formula units ) |
Element ( no unit ) |
|---|---|
| 1 | Si |
| 1 | C |
| Exposure Time ( h ) |
Maximum Temperature ( °C ) |
Furnace |
Corrosion Rate ( mg cm-2 h-1 ) |
|---|---|---|---|
| 5545 | 1040 | Al Remelt1 | - 54 |
| 530 | 1150 | Al Remelt2 | -241 |
| 4440 | 1175 | Forge | - 14 |
| 1455 | 1100 | Reheat | - 90 |
| 2280 | 925 | Soak Pit 1 | - 22 |
| 3460 | 1250 | Soak Pit 2 | -540 |
Surface recession rates were converted to corrosion rates.
| C-ring Test Temperature ( °C ) |
Pre-Test Furnace |
Flexural Strength ( MPa ) |
|---|---|---|
| 1100 | Al Remelt1 | 184 |
| 1100 | Al Remelt2 | 220 |
| 1100 | Reheat | 325 |
| 1100 | Soak Pit 1 | 162 |
| Amount of Element ( formula units ) |
Element ( no unit ) |
|---|---|
| 1 | Si |
| 1 | C |
| Exposure Time ( h ) |
Maximum Temperature ( °C ) |
Furnace |
Corrosion Rate ( mg cm-2 h-1 ) |
|---|---|---|---|
| 3460 | 1250 | Soak Pit 2 | -540 |
Surface recession rates were converted to corrosion rates.