Thermophysical data

based on the 100 steels program of Friedhelm Richter Investigated properties / measuring methods and measuring instruments

  • Density
    The density was determined by weighing in air and under water using a thermostated semi-microbalance.

  • Thermal expansion
    For measuring the thermal expansion, i. the average linear thermal expansion coefficient and the differential linear thermal expansion coefficient, a specially constructed Dilatometermessplatz was used with vertical sample positioning.

  • Young’s modulus and transverse contraction number
    The two elastic sizes, the modulus of elasticity and the transverse contraction number, were recorded by measuring the resonance frequencies of free-swinging rod-shaped samples. The “dynamic” quantities determined in this way can differ from the “static” sizes, in particular at higher temperatures, as determined in the tensile or bending test. For these investigations, the measuring arrangements with the designation “Elastomat” and “Tectanel” were available.

  • Specific heat capacity
    An adiabatic calorimeter was used to determine the heat content and thus the true specific heat capacity and the average specific heat capacity. The recent studies used a dynamic power-difference calorimeter.

  • Specific electrical resistance
    A specially constructed experimental setup allows the measurement of the specific electrical resistance. On rod-shaped samples, the specific electrical resistance in a thermostatted bath at 20 ° C can be determined. To determine the temperature dependence, thin sample plates are used, in which antiparallel Sägeschnitte be introduced to increase the electrical resistance.

  • Thermal conductivity
    Based on the law of Wiedemann-Franz-Lorenz, the thermal conductivity can be calculated, especially if one has derived the coefficients in the relationship of heat conductance and resistance measurements on samples of the steel to be examined with the same or similar composition.

  • Thermal conductivity
    From the determined values ​​of thermal conductivity, true specific heat capacity and density, the numerical values ​​for the thermal diffusivity result. For the direct measurement, the laser flash method was used for some steels.