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The work develops the models of two principal diffusional transformations in high-chromium iron alloys on continuous cooling, viz. precipitation of secondary carbides (Cr, Fe)7C3 from aus-tenite and pearlitic decomposition of the latter. Literature experimental data for alloys of various composi-tion were used for analysis. Chemical composition of austenite by the end of austenitizing holding was de-termined using previously developed models, and then the exact expression describing isothermal precipita-tion of carbides from supercooled austenite was found based on the general equation following from the ki-netic theory of phase transformations. It was found out that the time exponent n in that expression equals to 3/2, which corresponds to the case of preferred precipitation of very fine carbide particles. For transition to the continuous cooling condition the C-curve of isothermal carbide precipitation was approximated by a square parabola. This permitted to find the relation between cooling rate and the amount of precipitated car-bide phase by means of the Scheil–Steinberg integral. Further comparison with the experimentally observed increase of martensitic point allowed to determine the numerical parameters of the model and their depend-ence on carbide composition of a given alloy. For the pearlitic transformation, a previously developed mod-el describing the parameters of temperature dependence of the Avrami equation coefficients on austenite composition was employed. That model was generalized for the continuous cooling case in the same was as above. As a result, CCT diagrams of diffusional austenite transformations in high-chromium alloys were calculated, that in general corresponded well the experimental ones.

The paper presents the results of industrial testing parts made of experimental wear-resistant alloys. Cast iron was smelted with a high content of nickel and vanadium and steel with alloying elements, which vary widely over from 15% to thousandths. The prototypes wear resistance was increased by about 30-34%. The work was performed at Karaganda State Technical University. These studies were carried out as a part of the grant of the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan BR05236295 “Designing, Developing and Implementing Technologies of Producing and Machining New Generation Wear-Resistant Materials for Obtaining Parts of Metallurgical Units”.

The paper presents the results of studying the structure of products made of titanium carbide hardened by the impregnation method. As a bonding alloy a high-temperature alloy of the Fe-Cr-Ni-Co system was used. Samples of different porosity were impregnated with that alloy, then their structure was investigated by the methods of mercury porosimetry and electron microscopy. The data of the parameters of porosity and some mechanical properties are given. It was found that there is a correlation between the average size of open pores and the tensile strength and the ultimate strength limit. It is shown that this relationship is logical if to consider the resulting structure as a composite material: the matrix of titanium carbide which pores are filled with a metal bond. It is shown at what parameters of the porous structure the impregnation process proceeds most fully.