PSI - Issue 81

Anatolii Babinets et al. / Procedia Structural Integrity 81 (2026) 353–359

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materials with the purpose of improving the performance properties of the deposited metal have been largely exhausted. In this regard, modification (microalloying) methods, which open additional ways to control the structure and properties of the metal, are becoming increasingly relevant; however, as shown in the work of Babinets et al. (2021), they are still rather limitedly used in surfacing of parts. In the work of Babinets et al. (2021), it was shown that the main reasons for this are the rather complex effect of modifying additives (especially complex ones) on the peculiarities of structure formation of the deposited metal and its properties, as well as technological difficulties associated with the methods of introducing modifying additives into the deposited metal during arc surfacing processes. At the same time, in the works of Lobanov et al. (2023) and Ryabtsev et al. (2023), it was shown that the modification of deposited metal of heat-resistant steel type 25Cr5MoVSi (the European analogue of which is steel X37CrMoV5 1 according to EN 4957 (2018)) with boron and titanium carbides, by their introduction into the core of metal powder-cored wires (MPW), leads to an increase in the performance properties of the deposited metal by 1.5 times. MPW are multifunctional electrode materials consisting of a metallic sheath and a core in the form of a powder mixture. The core composition may include powdered materials such as pure metals, alloys, ferroalloys, carbides, and other additives that determine the chemical composition, structure, and properties of the deposited layer, as shown in the works of Pokhmurs`ka et al. (2018), Ilyushenko et al. (2019), Peremitko et al. (2022), and Trembach et al. (2025). One of the determining factors that affects the quality of deposited metal formation is the granulometric composition of the powder components. As experimentally confirmed in the work of Ryabtsev et al. (2024), the size and shape of the particles determine the stability of the wire melting process, the uniformity of distribution of alloying elements, as well as the homogeneity of the structure and properties of the deposited metal. As shown in the works of Zhudra et al. (2014), Babinets (2024), Ryabtsev et al. (2024), Adeeva et al. (2025), and Sivak et al. (2025), the available literature data on the influence of granulometry of metal powders on the processes of arc surfacing with MPWs remain limited and contradictory. The results of previous studies presented in the work of Babinets et al. (2025) showed that the use of fine-dispersed (50 –100 µm) metal granules formed by atomization from high -speed steel HS6-5-2C according to EN 4957 (2018) contributes to the improvement of surfacing stability and the refinement of the metal structure, whereas the use of granules with a wide granulometric composition (50 –300 µm) containing a significant amount of coarse powder fraction (200 –300 µm) negatively affects the process stability and the quality of the deposited layer. However, in most cases, the core of MPW contains metallic components in the form of ferroalloy powders and other metallic materials that differ significantly in morphology, chemical composition, and physical properties. Similar studies regarding the influence of dispersity of such MPW core components are practically absent, which creates a scientific gap in this field. Considering the above, a comprehensive study of the influence of introducing modifying additives, in particular B ₄ C, and the granulometric composition of metal powders in the MPW core on the structure and performance properties of the deposited metal is relevant. This will make it possible to optimize the process of arc surfacing with MPWs and to ensure the formation of defect-free coatings with enhanced heat and wear resistance. The purpose of this work is to study the influence of the introduction of B ₄ C modifying additives and the granulometric composition of the core of metal powder-cored wires on the peculiarities of structure formation of deposited metal of the 50Cr2Ni2MoVSi type, as well as its thermal stability and wear resistance under high-temperature friction conditions according to the “metal–metal” scheme. 2. Material and Research Methods For comparative studies, a series of five MPWs was manufactured. The sheath was formed from a steel strip of low-carbon steel DC01 according to EN 10130 (2006), 12 mm wide and 0.4 mm thick. The core contained a mixture of ferroalloys and metallic powders providing the required chemical composition of the deposited metal of the C – Cr – Ni – Mo – V – Si system. The wire design was tubular with edge overlap, 1.8 mm in diameter, and with a filling coefficient of 25%. The chemical composition of the core was selected to obtain deposited metal of wear- and heat-resistant steel 50Cr2Ni2MoVSi, whose closest European analogue is steel 55NiCrMoV7 according to EN 4957 (2018). As a reference, MPW No. 1 without modifying additives and with a standard granulometric composition (50 –300 µm) was used. Experimental MPWs (Nos. 2 – 5) were modified by introducing into their core B ₄ C powders in amounts ensuring boron content in the deposited metal within 0.01 – 0.1%. The granulometric composition of the core for MPWs Nos. 2 – 4 was 50 – 300 µm, while for MPW No. 5 it was 50–100 µm. Surfacing was performed on plates made of steel 41Cr4 according to EN 10083- 3 (2006), with dimensions 200×50×15 mm. The technological process was carried out under a flux layer by separate beads in four layers under identical conditions: voltage – 24 V, current – 220 A, surfacing speed – 20 m/h, bead spacing – 4 mm, reverse polarity, direct current. After surfacing, the samples were cooled in still air. The welding and technological properties were evaluated using a comprehensive method that included expert visual and calculated assessment. Visually, the stability of arc ignition, the quality of deposited metal formation, and the ease of slag crust separation were evaluated. The presence of defects in the deposited metal was determined using dye penetrant testing. Each parameter was assessed from 0 points (worst) to 2 points (best), and their total sum was determined. The process productivity was calculated based on melting, deposition, and loss coefficients. Process stability was evaluated by calculated coefficients of variation for current and voltage.