An industrial technology for thermal diffusion deposition of complex-alloyed protective coatings of the Ni-Al-Si-Cr-La system on heat-resistant nickel alloys ChS-70VM and EP-539LM has been developed and optimized. Saturation was carried out in powder mixtures based on ferroaluminum, ferrosilicon, and specially smelted Fe-Al-Si master alloys (20-30% Al, 15-25% Si) with the activator Na2SiF6 at 900-950 degrees C. The influence of temperature and time conditions of saturation and subsequent annealing on the coating growth kinetics, phase composition, and microstructure of the base was determined. It was shown that the optimal conditions (quenching at 1160 degrees C + aging at 1050 degrees C + saturation at 950 degrees C, 6-8 hours) provide a coating thickness of 40-60 & micro;m, a microhardness of 7500-9000 MPa, and the preservation of the structural stability of the gamma '-phase of the alloy. The coatings demonstrate twice the heat resistance and corrosion re-sistance in diesel fuel combustion products with the addition of sea salt compared to traditional aluminide coatings. Bench and engine tests (600 hours) confirmed the resource efficiency of the developed technology.
Abstract Problem Statement. Statistical methods of information gathering have been used for more than three hundred years, but each industry has its own specific output and input parameters for providing a general or separate assessment. In radiation safety, the Monte Carlo method has found wide application, which has a fairly clear toolkit but is highly dependent on the number of iterations, as well as on the parameters and speed of the computing machinery. The purpose of the study is to model changes in the formation of the total radiation dose of personnel at radiation-hazardous facility (RHF) depending on the selected input parameters; to determine the radiation risk; to select and compare analytically derived pairs of blocks using the graph method, matrix method, and SWOT analysis that occur at the RHF of the former uranium using artificial intelligence technologies in the Grok software package. Objectives of the research. The objectives of the research are: to consistently apply the method of graph, the matrix method, and the SWOT analysis method; to identify the comprehensive list of influencing factors present on the territory of the radiation-hazardous facility; to perform modeling; to determine the most significant factors affecting the formation of the total radiation dose of personnel; to select and compare analytically derived pairs of blocks using SWOT analysis, based on the existing technical, physicochemical, geological, and other conditions of the sites of the former uranium production facility of PCP. Conclusions. Based on the results of the developed models, using the methods: MG, MM and SWOT analysis, the values (possible ranges of variation) of: DER, IRD, SED, the total dose of radiation exposure to personnel of a radiation-hazardous facility were determined, depending on the model and the number of selected factors. A general flowchart was constructed for decision-making on optimizing the system “Radionuclide - Source of ionizing radiation - Technical regulations - Personnel - Radiation dose”.
The operation of full-scale columns within the bent of one-story and single-span industrial building with a foundation and a girder has been experimentally investigated under conditions similar to real operation. The full-scale tests have made it possible to reliably assess the stress-strain state of the columns undergoing compression and bending, to determine the horizontal displacements of the bent, to analyze the performance of joints, to study both global and local instability, and to identify the actual reserves of load-bearing capacity in the columns. These full-scale experimental studies have provided an objective assessment of the rationality of regulatory requirements to the design of such steel structures.
The paper presents the results of a study of the effect of hydrogen sulphide (H2S) on the mechanical properties and microstructure of heat-resistant 25CrMo4 steel subjected to heat treatment and exposure to H2S for 730 hours without external loading. An analysis of the fractal dimension of tempered martensite and lower bainite was performed, which revealed a direct dependence of the tensile strength and yield strength on the fractal dimension of martensite, as well as an inverse correlation of relative elongation and contraction with the fractal dimension of bainite. Heat treatment, which included quenching at 880°C and tempering at 650°C to achieve a hardness of no more than 22 HRC, ensured initial stability, but exposure to H2S caused hydrogen embrittlement, manifested in a decrease in plasticity. Fractal analysis provides the ability to predict the mechanical properties of 25CrMo4 heat-resistant steel in aggressive environments by analysing structural elements (tempered martensite and lower bainite). This approach suggests the possibility of optimising heat treatment modes to improve the corrosion resistance of steels.
The work compares various radiometry methods for accurately mapping fault zones in complex and simple mining and geological conditions. It also examines the conditions required for their application to confidently evaluate the degree of geodynamic activity of the identified tectonic fault zones, including minimizing negative impacts during the construction of various facilities, including linear transport and energy infrastructure. The authors analysed various materials on previously conducted research on this topic to compare approaches to the problem and develop numerical dependencies. In addition, it was evaluated the dependencies obtained by many researchers and their advantages and disadvantages. After thoroughly analysing previously developed methods and numerical dependencies for determining the degree of activity of tectonic faults, the most preferable method was selected from the list based on several criteria. The applicability parameters of the previously proposed numerical scale of fault activity based on radonometry data were clarified. The numerical scale itself was significantly improved. Based on the analysis of existing radonometry methods, the most acceptable method and an improved universal scale for determining the activity of tectonic faults, which is quite suitable for practical purposes, were proposed. The developed universal numerical scale still has no analogies. Radonometry in its various forms can be used to reliably evaluate the degree of geodynamic activity of the identified tectonic fault zones. For this purpose, the corresponding methodology and numerical scale were chosen.
