QUANTITATIVE METALOGRAPHY OF HEAT TREATED S6K SUPERALLOY

Alloy S6K is former USSR superalloy used in DV – 2 jet engine. It is used for turbine rotor blade and whole cast small sized rotors with working temperature up to 800 ÷ 1050°C. This alloy was evaluated after annealing at 800 °C/ 10 and followed by cooling with various rate, presented with cooling in water, oil and air. Cooling rates, represented by various cooling mediums, have a significant influence on diffusion processes, which are going in structure. Methods of quantitative metallography (Image Analyzer software NIS – Elements for carbides evaluation, measuring of secondary dendrite arm spacing and coherent testing grid for gama' - phase evaluation) are used for evaluation of structural characteristics on experimental material – Ni base superalloy S6K.