High-temperature processing parameters in steel production (Casting, rolling, hot forming, heat treatment) are significantly influenced by the kinetics of grain growth, recrystallization, precipitations and phase transformations. Over the last 20 years, High-temperature Laser Scanning Confocal Microscopy (HT-LSCM) has been established for the in-situ observation of these processes. One focus of the present master thesis is the development of a continuous investigation method for austenite grain growth, which consists of sample production and adaptation, in-situ observation, and analysis. This master thesis shows that remelting and centrifugal casting of samples with subsequent hot forging leads to homogeneous samples and excellent reproductive measurement results. The prepared method is used for observation of the grain growth in binary and ternary iron-based alloys at temperatures between 950 and 1250 degrees. The influence of alloying elements such as carbon, chromium and molybdenum is as clearly visible as that of precipitates, especially aluminum nitrides. Finally, the austenite transformation during the cooling process is observed. The determined transformation temperatures are then compared with the results of dilatometer measurements and model calculations. This method proves to be very sensitive to the influence of the austenitization temperature, the holding period and cooling rate. The accordance with the results of the dilatometer measurement is excellent. The HT-LSCM turns out to be an efficient and precise method for observation of grain growth and phase transformations in steels at high temperature. In the future, the compiled method will be used as a standardized measurement procedure.