Metal Science and Heat Treatment

Maisuradze, M. V.; Ryzhkov, M. A.; Kuklina, A. A.; Antakov, E. V.; Nazarova, V. V.

doi: 10.1007/s11041-024-01063-9pmid: N/A

An improved method is suggested for predicting the fractions of microstructure constituents formed in alloy steels during austempering and one-step quenching-partitioning in the temperature range of martensitic transformation. The temperature dependence of exponent n of the Austin–Rickett equation modeling the kinetics of isothermal bainitic transformation at a temperature below Ms is obtained using dilatometric studies of a number of steels. The developed method also allows for the equilibrium condition of the α- and γ-phases, which characterizes suspension of the bainitic transformation during isothermal holding, as well as the inevitable formation of carbides. The method enhances the adequacy of prediction as compared to the traditional methodology.

Yurgin, A. B.; Ruktuev, A. A.; Lazurenko, D. V.; Shikalov, V. S.; Chakin, I. K.

doi: 10.1007/s11041-024-01064-8pmid: N/A

The method of non-vacuum electron beam cladding is used to obtain coatings based on a high-entropy Cantor alloy reinforced with Cr3C2 particles. The microstructure of the coatings is studied; the chemical and phase compositions are determined; microhardness measurements, wear resistance and heat resistance tests are performed. The structure of the coatings is represented by an fcc matrix with Me7C3 carbides. Increase in the percentage of reinforcing particles leads to elevation of the proportion of the carbide phase in the cladding layer. The addition of carbide particles results in growth of the microhardness, wear resistance and oxidation resistance. The structure of the coating obtained from a powder mixture with 50 wt.% Cr3C2 exhibits a 60% volume fraction of carbides. The properties have the highest values in the coating obtained from a mixture with 50 wt.% carbide particles in the initial composition. Its hardness is 1071 ± 114 HV0.1, and the wear resistance and the oxidation resistance increase with respect to the unreinforced coating by a factor of 15.3 and 3.3 respectively.

Burkov, A. A.; Kulik, M. A.; Bytsura, A. Yu.

doi: 10.1007/s11041-024-01065-7pmid: N/A

Al – Ni – Fe coatings on steel 35 deposited by the electrospark method using a non-localized electrode and mixtures of nickel and aluminum granules are studied. The kinetics of the mass transfer of mixtures of granules of three compositions during application of the coatings is investigated. The phase composition, the microstructure and the hardness of the coatings are determined. Corrosion and wear tests are carried out. It is shown that the deposition of Al – Ni – Fe coatings on the steel can reduce its susceptibility to spontaneous corrosion, lower the corrosion current density by a factor of 1.6 – 2.6, raise the wear resistance by a factor of 3.7 – 6.2 and elevate the heat resistance.

Kondrat’ev, S. Yu.; Ermakov, B. S.; Shvetsov, O. V.; Alfimov, A. D.

doi: 10.1007/s11041-024-01066-6pmid: N/A

Comparative tests of mechanical characteristics of aluminum and steel pipes under static and cyclic loading are described. The mechanism of fatigue failure of drill pipes made of aluminum alloy 1953T1 and steel G-105 is analyzed. The endurance limit of the drill pipes made of 1953T1 alloy and G-105 steel is 192 and 507 MPa, and the ratio of the endurance to the yield strength is 32 and 66%, respectively. However, the strength/density ratio under cyclic loading of aluminum alloy 1953T1 is at the same level as that of steel G-105, and under static loading it significantly exceeds the values for steel G-105. This makes it possible to recommend the use of aluminum alloys for manufacturing drill pipes instead of steel ones for service under rigid operating conditions.

Lukyanova, E. A.; Dobatkina, T. V.; Tarytina, I. E.

doi: 10.1007/s11041-024-01067-5pmid: N/A

The effect of additional alloying with several rare earth metals in an amount of up to 5 wt.% on the aging kinetics of a high-strength heat-resistant magnesium alloy IMV7-1 of the Mg – Y – Gd – Zr system is studied. Features of influence of the added rare earth metals on the properties of alloy IMV7-1 are determined depending on their atomic number and belonging to the cerium or yttrium group.

Konovalov, M. S.; Lad’yanov, V. I.; Mokrushina, M. I.; Ovcharenko, P. G.

doi: 10.1007/s11041-024-01068-4pmid: N/A

Metal matrix composites based on a Fe – Cr – Mn – Mo alloy obtained by the method of self-propagating high-temperature synthesis in the version of aluminobarothermy are studied. It is shown that the reinforcing particles in the composite are structured conglomerates, in which two regions can be distinguished: central (mainly composed of magnesium oxide) and peripheral (mainly composed of aluminum nitride) ones. Increase in the content of the nonmetallic phase first leads to an increase in the number of similar predominantly single inclusions (at 1.09 – 1.73 wt.% phase), and then they are combined into groups (at 1.90 – 3.38 wt.% phase). The influence of the concentration of the structured conglomerates on the mechanical properties and the wear resistance during dry friction of the composites is determined.

Calik, Adnan; Ucar, Nazim; Semercý, Alper

doi: 10.1007/s11041-024-01069-3pmid: N/A

The weldability and mechanical properties of welded joints of pipeline steels of grades API 5L (X52, X60, X65 and X70) manufactured by submerged arc welding (SAW) are investigated. It is shown that the SAW process makes it possible to obtain high-quality welded joints. It is shown that such welded joints fracture during tensile tests over the base metal region. The weld region has the highest hardness and ultimate tensile strength, which are 214 HV10 and 713 MPa for steels X70 and X65 respectively. These values are higher than that of the base metal.

Belgibaev, E. R.; Semenov, M. N.; Kayumov, R. R.; Gaisin, Az. F.; Gaisin, Al. F.

doi: 10.1007/s11041-024-01070-wpmid: N/A

The possibility of using plasma-liquid welding with direct current electric discharge at atmospheric pressure to manufacture products from electrical steel E-310 is studied. The samples are welded by immersing a metallic cathode (the welded parts) into a liquid (non-metallic) anode. The electrophysical parameters of the welding process are determined, including the current-voltage characteristic and the current and voltage fluctuations. The results of the analysis of the morphology and of the microhardness of the weld are presented. The prospects of plasma-liquid welding of parts from electrical steel E-310 are demonstrated at an appropriately chosen mode of the variable resistor.

Arkhipov, V. E.; Kuksenova, L. I.; Moskvitin, G. V.; Pugachev, M. S.

doi: 10.1007/s11041-024-01071-9pmid: N/A

The process of formation, the structure, and the phase composition of coatings based on copper and zinc and deposited by cold gas-dynamic spraying are studied. It is shown that a multiphase structure is formed in the coating based on a solid solution of copper in zinc, a solid solution of zinc in copper and solid solutions based on electron compounds CuZn3 and Cu5Zn8. At a low spraying temperature (270°C), the formation of the structure is mainly influenced by interboundary diffusion. The total diffusion rate is Dc = 0.15 × 10–12 m2/sec. When the spraying temperature is increased to 360°C and higher values (450°C), the vacancy diffusion mechanism prevails. The diffusion rate increases to Dc = 0.56 × 10–12 m2/sec, which is accompanied by an increase in the mass fraction of the transformation products. A model of formation of the multiphase gradient coating structure is suggested and the influence of the spraying parameters on the formation of the structure is discussed.

Filyakov, A. D.; Pochetukha, V. V.; Romanov, D. A.; Vashchuk, E. S.; Gromov, V. E.

doi: 10.1007/s11041-024-01072-8pmid: N/A

The microstructure of a new TiB2 – Ag metal matrix composite coating deposited by electrical explosion spraying and modified by electron beam treatment is studied using x-ray diffraction analysis and scanning and transmission electron microscopy. It is shown that the phase composition of the coating depends on the deposition mode, and the subsequent electron beam treatment normalizes it. The main phases of the resulting modified coating are Ag, TiB2 and B2O. After the electron beam treatment, the microstructure of the coating transforms. The nanostructure of the silver matrix is transformed into a nanocrystalline structure with an average crystal size of tens to hundreds of nanometers.