The dependence of the martensite structure on the volume fraction of coherent inclusions inherited from aged austenite has been studied. An explanation for the considerable martensite lattice tetragonality in the case of thin martensite twins in comparison with their inclusion diameter is suggested. A reason for surface relief height decreasing for alloys with narrow temperature hysteresis of transformation has been discovered.

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The paper describes the temperature cross-correlation velocimetry method applied to flows of water or liquid metal. The technique allows us to measure temperature waveforms and averaged longitudinal velocity in a flow simultaneously. This approach is a simple and reliable method for measuring the velocity in flows of opaque coolants. At the same flow parameters, liquids of different origins provide non-similar spatial-temporal characteristics having a different impact on the applicability of the temperature correlation method. This work is devoted to the development of practical methods allowing to form a set of specific recommendations on the application of the technique of temperature correlation velocimetry and to determine the metrological characteristics of the technique in various conditions. Calibration was carried out using water and mercury as a model liquid. Used experimental facility and measuring system are described, accompanied by a detailed description of the developed temperature-correlation sensor. Measuring directly from within a flow is made possible by a unique micro thermocouple immersion probes technique. Data obtained are presented as fields of temperature and intensity of temperature fluctuations. Autocorrelation and cross-correlation functions are compared and analysed for two studied fluids under identical conditions.

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