The mechanical properties of metallic materials at high temperatures differ significantly from those at room temperature, and the influencing factors are much more complex. At room temperature, the mechanical properties of materials have little relation to the load holding time, but at high temperatures, the material properties are closely related to time.

The high-temperature furnaces adopt cascade temperature control. Three fixed thermocouples measure the furnace chamber temperature, and three thermocouples measure the specimen surface temperature. The armored thermocouples are equipped with elastic connection devices, which can maintain good contact with the specimen surface throughout the test and accurately measure the specimen surface temperature. A rotating sliding guide bracket is adopted, and the extensometer is fixed on a height-adjustable support. The extensometer is designed with two ceramic rod extension arms that contact the specimen in the furnace chamber through gaps in the side walls of the high-temperature furnace. The gauge length of the extensometer can be fixed or variable, covering the requirements of 25mm and 50mm gauge lengths. The measurement range is ≥15% for tensile absolute strain and ≥5% for compressive absolute strain, meeting the requirements of ISO 9513 Class 0.5 and ASTM E83 B1, with an applicable temperature ≤1100℃.