ASTM C1171 – Standard Test Method for Quantitatively Measuring the Effect of Thermal Shock and Thermal Cycling on Refractories
Description:
Significance and Use
3.1 This test method indicates the ability of a refractory product to withstand the stress generated by sudden changes in temperature.
3.2 Because the recommended furnace temperature of this cycling test is 1200 °C (2190 °F), this test method may not indicate the ability of a refractory product to withstand cycling at higher or lower temperatures, especially if the existing morphology of the refractory product changes.
3.3 This test method is useful for research and development, as well as for comparing refractory products. The precision should be considered when using this test for specification purposes.
3.4 Ruggedness tests found the following variables to be rugged:
| Temperature | +5 °C |
| Hot spacing | 1/2 to 3/4 in. (12.77 to 19 mm) |
| Cold spacing | 1/2 to 3/4 in. (12.77 to 19 mm) |
| Center versus end gripping of the bars | |
| Hot hold time | 10 to 15 min |
| Cold hold time | 10 to 15 min |
| Operator air speed | 0 to 2 mi/h (0 to 3.2 km/h) |
| Initially cold or heated samples | |
| Last in, first out (LIFO); or first in, first out (FIFO) removal from the furnace | |
| Sawed or original surface as tensile face during MOR testing | |
| Bar thickness | 0.96 to 1.04 in. (24.5 to 26.4 mm) |
Scope
1.1 This test method is used for determining the strength loss or reduction in continuity, or both, of prism-shaped specimens which are cut from refractory brick or shapes and subjected to thermal cycling.
1.2 The strength loss is measured by the difference in modulus of rupture (MOR) between uncycled specimens and the specimens subjected to thermal cycling.
1.3 The reduction in structural continuity is estimated by the difference in sonic velocity before and after thermal cycling.
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
ASTM C117