Studies of the Thermophysical Properties of Selected Hot-Working Tool Steels in a Wide Temperature Range

In this work, measurements of the thermal diffusivity and thermal expansion of hot-working tool steel WLV (1.2365) were carried out in the temperature range from (-)50 °C to 500 °C. The results of these measurements were compared with those published earlier by the authors for other selected hot-working tool steels, i.e., 38HMJ (1.8509) and WCL (1.2342), in the temperature range from (-)50 °C to 500 °C and from room temperature (RT) to 1100 °C. This paper describes the procedures used to relate the thermal characteristics of the thermal diffusivity and thermal expansion obtained at low temperatures to those obtained at high temperatures. Thermal diffusivity and thermal expansion of WLV, 38HMJ and WCL steels in the temperature range from (-)50 °C to 1100 °C were used as input data for numerical simulations of heat transfer in devices made of these steels and operating in a wide temperature range. Thermophysical properties were tested using specialized NETZSCH test stands. Thermal diffusivity was studied using a LFA 467 light flash apparatus in the temperature range from (-)50 °C to 500 °C and a LFA 427 laser flash apparatus in the temperature range from RT to 1100 °C. Thermal expansion was tested using a DIL 402 Expedis dilatometer in the range from (-)50 °C to 500 °C and a DIL 402 C dilatometer in the temperature range from RT to 1100 °C. Finally, the results of tests on thermophysical properties of selected steels in the temperature range from (-)50 °C to 1100 °C were summarized.