This work studied the effect of the amount of additives and the composition of refining slags on the metallurgical of steel grades of the S355G10, S420G2, and S460G2 types. The objects of study were samples of industrial melts after out-of furnace refining of steel with different amounts and nature of additives. Based on the results obtained, the recommended amounts of additives and the composition of the refining slag have been developed, which makes it possible to reduce the metal contamination with non-metallic inclusions.

Cast alloy steel grade 35KhGSL is widely utilized in various industries. Sometimes, wear resistance and hardness become highly essential for different machine parts. Additions of ultradispersed powders in melt as modifiers, external impact on crystallizing alloy are two important approaches to enhance the mechanical characteristic. In this work, a combination of ultrafine modifier in the form of titanium carbide TiC and mechanical vibration was used for the first time on cast alloy steel grade 35KhGSL in order to study changes in hardness and wear resistance. The method of introducing a modifying additive into the melt is indicated. The analysis has been carried out based on hardness, tribological properties, and microstructural characterization. The microstructural was analyzed using metallographic microscope and scanning electron microscope (SEM) analysis. In addition, the Vickers microhardness values were measured, and dry abrasion test was conducted to check the steel's variation in hardness and tribological characteristic after treatment. The combination of mechanical vibration of the crystallizing melt with the simultaneous introduction of titanium carbide powder maximized the hardness of 285 HV (by 36%) and wear resistance. It was recommended to include modification and mechanical vibration operations in the production technology of the "Sprocket" casting at the Parkhomenko Foundry Machine-Building Plant (Karaganda, Republic of Kazakhstan). This type of casting is used in conditions of intensive wear.

This study aimed to improve the hardness and wear behavior of medium-carbon alloy steel through the addition of titanium carbide ultradispersed powder and low-frequency vibration treatment during solidification. It was shown that the complex effect of low-frequency vibration with the additional introduction of a small amount of titanium carbide ultradispersed powder with the size of 0.5–0.7 μm during the casting process had a positive effect on structural changes and led to improved mechanical properties, and so increasing the value of microhardness by 37.2% was notable. In the process of shock dynamic impact, imprints with crater depths of 13.69 µm (500 N) and 14.73 (700 N) were obtained, which, respectively, are 23.34 and 42.34% less than that on the original cast sample. In the process of tribological testing, decreasing the depth of the wear track (50.25%) was revealed with decreasing the value of the friction coefficient by 14.63%.