Proven Excellence. Refractories under Load and Creep in Compression - RUL/CIC 421 Analyzing & Testing

The testing of refractories - clearly an essential process - includes the following applications: ■ Prediction of service conditions ■ Quality control of the process and the product ■ Mathematical modeling for product improvements Today, selection of the proper refractory material is more crucial than ever when it comes to improving the cost-effectiveness of a process and prolonging the life cycle. Appropriate selection of the refractory furnace lining can only be made with accurate knowledge of the properties of the refractory materials and the stresses on the materials during service. Thermomechanical...

NETZSCH Instruments for Testing Refractories under Thermal and Thermomechanical Stress Thermal and Thermomechanical Properties Temperature Range Refractoriness under Load (RUL) Refractoriness under Load/ Creep in Compression (CIC) Creep in Compression (RUL/CIC 421) Thermal Expansion (DIL) Dilatometer Volume Stability (DIL) (DIL 402 E, DIL Expedis series) Thermal Stress Specific Heat Capacity (LFA) Specific Heat Capacity (DSC) Thermal Diffusivity/ Temperature Range Laser/Light Flash Apparatus (LFA 427, Differential Scanning Calorimeter (DSC 404 F1/F3 Pegasus®) Laser/Light Flash Apparatus (LFA...

Refractoriness under load evaluates the behavior of fired refractory bricks under rising temperature and constant load conditions. Refractoriness under load (RUL) is a measure of the resistance of a refractory product to subsidence when subjected to the combined effects of load, rising temperature at a predefined heating rate. The range in which softening occurs is not identical with the melting range of pure raw materials, but it is influenced by the content and the degree of distribution of low melting point fluxing agents. The RUL test method is described in ISO 1893, Refractoriness under...

Creep in Compression Variable load Loading column Heating element Sample Protective tube Inner thermocouple Outer thermocouple Control thermocouple Outer tube Inner tube Hood type furnace Supporting column Sample with coaxial bore and inner tube Bellows Vacuum-tight seal Variable contact force Gastight casing Evacuating system Inductive transducer Gas inlet Schematic of the gas-tight RUL/CIC 421 for measurements in protective gas atmosphere Measuring Unit – Specimen Signal Generation – Expansion The measuring unit consists of a console, furnace guide frame, furnace (max. 1700°C), balance weight...

Test Atmosphere Measurements can be carried out in static air (basic version) or using an optional device for inert gas purge within the test piece area. For testing carbon-containing materials (e.g., magnesia-carbon graphite bricks), a non-oxidizing test atmosphere can be realized with a gas-tight test chamber (optional; see figure on previous page). This chamber can be evacuated and then purged with protective gas. Measurements can be carried out up to 1600°C. Optionally, the loading device can be equipped for load variation. The preload can be up to 300 N and the verifying load can be applied...

The upper plot shows a RUL measurement (differential) on a test piece of a fireclay brick with increasing temperature. At 1387°C, the test piece reaches its maximum expansion. Deformations of 0.5% and 1.0% occurred at 1565°C (T0.5) and 1600°C (T1), respectively. Peak: Peak: 1387.0 1387.0 °C °C Peak: 1387.0 °C 800 1000 800 1000 Temperature // °C 800 Temperature °C 1000 Temperature / °C Refractoriness under Load; test conditions: 0.2 N/mm², 5 K/min, static air The lower one shows the timescaled creep over 25 hours at a constant temperature of 1280°C. 1.0 1.0 1.0 Peak: Peak: 1283.0 1283.0 °C °C...

Refractoriness under Load (RUL) of Andalusite Bricks This plot shows three measurements on andalusite bricks fired at three different temperatures: 1430°C, 1470°C and 1510°C. At approx. 1425°C, all three test pieces reach their maximum expansion. After applying sample or calibration curve correction, the software calculates the characteristic T0.5, T1 and T2 temperatures from the RUL tests where 0.5%, 1% or 2% shrinkage is reached after the maximum expansion. The influence of the firing temperature can be clearly seen. RUL behavior of andalusite bricks (approx. 65% Al2O3) fired at three different...

Creep in Compression (CIC) of Andalusite Bricks Test pieces of the andalusite bricks fired at different temperatures are used for CIC tests. In these tests, the load is applied once the temperature is reached (here, at 1425°C). This is contrary to RUL tests, where the load is applied from the very beginning of the measurement. This plot only shows the time-scaled creep at constant temperature (the heating segment is not depicted). 1430 of andalusite bricks (approx. 65% Al2O3) fired at three different 0.1 CIC behavior 1470 temperatures; test conditions: 0.2 N/mm2, 5 K/min, static air, 25 h at...

State-of-the-Art Software Including Various Evaluation Routines ■ Graphic and tabulated results, calculated according to ISO/DIN ■ Correction of the measured data by calibration curves ■ Determination of characteristic data according to user's requirements ■ Automatic softening point detection ■ Derivation of curves for determination of the temperature-or time-dependent linear expansion rates ■ Possibilities for temperature control (max. 96 isothermal or dynamic temperature program steps) ■ Presentation of the measuring values temperature- or time-scaled for RUL and time-scaled for CIC ■ Determination...

RUL/CIC 421 E/6 The RUL/CIC runs under Proteus® software on Windows® for the fully automatic test run, data acquisition, storage and offline evaluation. Temperature range Heating elements Test atmosphere Safety switch Test piece Load range Measuring range Measuring system Digital resolution Thermocouples Power Supply Electronics ■ Semi-automatic routines for the determination of reaction steps as extrapolated onset, point of inflection, peak, peak end ■ Output or ASCII file export of the corrected measuring data ■ Data transfer of the sample length from an external gauge (optional) Static air;...