Effect of preliminary thermal treatment on decomposition kinetics of austenite in low-alloyed pipe steel in intercritical temperature interval

The decomposition kinetics of austenite that appears in the 13KhFA low-alloyed pipe steel upon heating the samples in an intercritical temperature interval (ICI) and exposure for 5 or 30 min has been studied by the method of high-speed dilatometry. The results of dilatometry are supplemented by the microstructure analysis. Thermokinetic diagrams of the decomposition of the γ phase are represented. The conclusion has been drawn that an increase in the duration of exposure in the intercritical interval leads to a significant increase in the stability of the γ phase.     

Study of the Thermal Technical Characteristics of a Combined Solar Desalination and Drying Plant

The paper presents the results of calculated research on determining the thermal technical indicators of a combined solar desalinization and drying plant. The structure of the plant is developed and proposed. A mathematical model is developed that describes the thermal processes occurring in the plant based on heat-balance equations solved using the Laplace method.     

Improvement of a Set of 13Cr11Ni2W2MoV Steel Mechanical Properties for Critical Components of Stop Valves of Oil and Gas Pipelines Using Intercritical Quenching

Metallurgist - A heat treatment regime for steel 13Cr11Ni2WMoV quenched from 980°C with the aim of simultaneous achievement of the required values of impact toughness and strength is...     

Technique for calculating geometric dimensions of a greenhouse-type solar-based one-cascade apparatus for demineralizing water

The results of studying a portable solar-based oblique multistep water demineralizer having increased productivity in obtaining distilled water are presented. The apparatus was designed taking the correlation for its geometric dimensions into account and using a capillary-porous material.     

Possibilities of strengthening of Fe-Cu alloys upon isothermal aging

The kinetic theory of diffusion phase transformations is used to calculate the time it takes for the ɛ phase to form in Fe-Cu alloys at various temperatures. The fine structure and hardness of alloys containing from 0.6 to 5.5 at % Cu and aged in the martensite state are studied. The calculated and experimental data are in good agreement. The cooling rate of copper-bearing alloys that provides the maximum hardness upon the precipitation of ɛ-phase particles of a given size is estimated.     

Impact toughness and plastic properties of composite layered samples as compared to monolithic ones

Effects of testing conditions on the mechanical properties and fracture of a material in the course of impact loading have been studied. Using steels of various phase compositions (ferritic steel 08Kh18T1 and austenitic steel 10Kh18AG19) tested in a wide temperature range (from 20 to ?196°C), the advantage of layered structures has been established as compared to monolithic. It has been shown that the testing of composite samples simulates the loading-affected behavior of the ferritic steel 08Kh18T1 with an inhomogeneous layered microstructure obtained during repeated hot rolling with a reduction of no less than 65%.     

On the mechanism of nucleation of copper precipitates upon aging of Fe-Cu alloys

Structure of the Fe-5.5% Cu alloy has been studied after aging at 500°C to show that the lattice of copper precipitates changes with increasing time of holding at a temperature from bcc to 9R to fcc. The free energy of the solid solutions and the phase-separation diagrams of the bcc and fcc phases of copper have been calculated. Barriers for the nucleation of copper particles with the bcc and fcc lattices have been evaluated. Factors that favor the appearance of intermediate structural forms of copper, which precede the formation of the stable fcc phase, are discussed.