| Abstrakt: |
Currently, in the view of industrial development, there is a need to obtain steel products designed for heavy loads. As known, the most common approaches are used to obtain steels with an advanced set of mechanical, service, and operational properties: regulating the carbon content, determining the rational content of basic elements, heat-treatment and microalloying regimes. The purpose of the paper is to study the features of the microstructure, structural components, and microsegregation during titanium microalloying of steels with an increased carbon content of 0.70-0.76% wt. Samples are studied after casting and hot deformation with subsequent heat treatment. Metallographic analysis, mechanical test, chemical analysis, x-ray diffraction method are used. The studies carried out in this work show that the microalloying of steel with titanium contributes to the reduction of grain sizes and structure imperfection, leads to a decrease in the size of dendrites of γ-iron solid solution and the interdendritic distance, compared to steel without microalloying. In addition, it is shown that the use of such microalloying leads to an increase in the number of types of the phases formed. According to the results of x-ray diffraction analysis, the following phases are additionally detected: MnSi, Fe0.4Mn3.6C, FeSiC and TiC, in comparison with steel without titanium microalloying. The obtained result enables to conclude that titanium reduces the solubility of carbon, manganese, and silicon in structural components. After a full circle processing, steels microalloyed with titanium have an improved set of mechanical properties (increase in strength limit and yield stress by ≅ 10%, compared to steel without titanium microalloying). [ABSTRACT FROM AUTHOR] |
