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Russkikh, I. M.; Shatsov, A. A.
doi: 10.1007/s11041-023-00904-3pmid: N/A
The effect of thermocycling treatment (TCT) on the physical and mechanical properties of low-carbon martensitic steel 15Kh2G2NMFB is studied. The thermocycling treatment consists of 3, 5, 7, 9 and 10 cycles. Each cycle involves air quenching from 950°C and subsequent tempering at 650°C. The microstructure of the steel is studied by metallographic, electron microscope and x-ray diffraction analyses. The values of the resonance frequency are determined for each mode of TCT. High values of resonance frequency (115,900 Hz) and minimum range of the temperature coefficient of frequency are obtained after 9 and 10 cycles of TCT.
Fakhurtdinov, R. S.; Puchkov, Yu. A.; Karpukhin, S. D.; Medvedev, P. N.; Degtyareva, A. G.
doi: 10.1007/s11041-023-00905-2pmid: N/A
The effect of quenching modes on the structure, phase composition and hardness of austenitic-ferritic stainless steel 20Kh25N8AD3M2 is studied by optical microscopy, x-ray diffraction phase analysis and hardness measurement. Corrosion tests are conducted in a 3% aqueous solution of NaCl with the use of potentiometry and potentiodynamic analysis. Heat treatment modes improving the resistance of steel 20Kh25N8AD3M2 to general and pitting corrosion are suggested. It is shown that aluminum and titanium used to deoxidize the steel can cause pitting corrosion even after quenching.
Shaburova, N. A.; Pashkeev, I. Yu.
doi: 10.1007/s11041-023-00906-1pmid: N/A
The possibility of acceleration of processes of thermal diffusion chromizing of steels by introducing additions (electron and oxygen anion emitters) into the saturating mixture is considered. A microscopic x-ray spectrum analysis of specimens chromized in powder mixtures with and without emitters is performed. The composition and the thickness of the diffusion layer are determined. It is shown experimentally that electric current emerges in the filler at the saturation temperature. The influence of the intrinsic thermionic field on the diffusion processes is explained.
doi: 10.1007/s11041-023-00907-0pmid: N/A
Comparative analysis of the effect of microalloying with niobium, vanadium and titanium on the processes of structure formation in low-alloy low-carbon steels subjected to hot plastic deformation by controlled rolling is performed. The concentration and temperature ranges of the influence of these elements on formation of austenite preceding the hot plastic deformation or occurring in the final stage of the controlled rolling before the start of polymorphic γ → α transformation are determined. It is shown that the inhibitory effect of the microalloying elements on the growth of the austenite grains in heating in the γ -range intensifies in the V → Nb → Ti order, and the capacity to retard recrystallization of the hot-deformed austenite intensifies in the V → Ti → Nb order. The microadditions of niobium are shown to have a dual effect on the kinetics of the polymorphic γ → α transformation.
Sorokina, S. A.; Vorob’ev, R. A.; Gorshunov, M. G.; Chernigin, M. A.
doi: 10.1007/s11041-023-00908-zpmid: N/A
A fragment of a pipe from a chromium-manganese steel of type 12Kh15G9ND (AISI 201) is studied after 1.5 years of operation in an apartment building. The chemical composition of the steel is determined. The Vickers hardness of straight and curvilinear parts of the pipe is measured. The temperatures Ms and Md of martensitic transformations are computed. The macrostructure and the microstructure of the steel are studied. Places of through corrosion damage and causes of their formation in hot water supply (HWS) pipes are analyzed. A method of scratch testing is suggested for assessing the surface condition. The adhesive properties of the coating are estimated. It is inferred that steel 12Kh15G9ND is suitable for service in HWS systems and that total replacement of the chromium-nickel steel in pipelines by a chromium-manganese corrosion-resistant one requires further study.
Patro, Sudhansu; Saxena, Kuldeep Kumar; Behera, Ajit
doi: 10.1007/s11041-023-00909-ypmid: N/A
The dependence of microstructure and mechanical properties on the thickness of Ni/Ti coatings deposited on a Si(100) substrate by magnetron sputtering and on the temperature of their subsequent annealing is studied. The thickness and the surface roughness of the coatings are determined using profilometry and atomic force microscopy. Nanoindentation is used to determine the penetration resistance, the hardness, and the modulus of elasticity. The layers with minimum thickness are shown to possess the highest mechanical properties. Annealing conducted after the sputtering results in gradual retardation of the process of coarsening of atomic clusters and improvement of the mechanical properties of the layer.
Rashidov, B. P.; Abdullaev, B. A.; Rakhimov, R. V.
doi: 10.1007/s11041-023-00910-5pmid: N/A
Corrosion resistance of aluminum and aluminum-based alloys is analyzed from the standpoint of their use for railroad transport (freight and passenger) in aggressive environments. The effect of alloying elements on the operating characteristics of the aluminum alloys is considered. The advantages of aluminum-based alloys with expected high corrosion resistance for replacing container and car steels are presented.
Raheja, Gagandeep Singh; Prakash, Chander; Sehgal, Shankar
doi: 10.1007/s11041-023-00911-4pmid: N/A
A novel surface engineering technology involving a powder-fed friction stir process (APF-FSP) is suggested for fabricating an Al5086 – GRN – ηSiC hybrid surface composite. The structure of the composite is studied by scanning and transmission electron microscopy. The ultimate compressive strength, the HV hardness and the modulus of elasticity of the composite are determined. It is shown that the structure of the composite is represented by aluminum matrix grains up to about 8 μm in size and uniformly distributed graphene/nano-SiC (GRN/nano-SiC) reinforcements. The graphene forms multilayer atomic clusters in the aluminum matrix due to mechanical exfoliation of the graphite. The composite obtained has high hardness (145 HV0.3) and ultimate compressive strength (385 ± 5 MPa).
Emurlaev, K. I.; Lozhkin, V. S.; Bataev, I. A.
doi: 10.1007/s11041-023-00912-3pmid: N/A
Special features of structural transformations in steel 40Kh under friction observed in an operando experiment are studied using diffraction of synchrotron radiation. Variation of the chemical inhomogeneity of martensite under friction loading is determined and the effect of this phenomenon on defects of the crystal lattice of martensite is analyzed. It is shown that the interaction in the “alloy VK20 – steel 40Kh” pair under the specified conditions causes oxidation of the iron-carbon alloy and thus contributes into occurrence of steady friction wear.
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