Development and improvement of roll casting technologies for universal beam mills

The object of this research is the casting technology of double-layer rolls for universal beam mills (UBM). They are critically important components of the metallurgical industry, ensuring the production of beams, profiles, and other structural elements, widely used in construction, mechanical engineering, transport, energy, and other industries. Developing innovative approaches to manufacturing rolls is strategically important for strengthening Ukraine's production potential. Since one of the most problematic areas is the dependence on imported rolls, which leads to significant economic losses, logistical risks and restrictions on the country's technological independence. Existing domestic technologies do not always lead to achieving the necessary operational characteristics, such as wear and heat resistance, and durability, complicating the competitiveness of products on the international market. The work proposes an innovative technology for manufacturing two-layer rolls, using stationary casting molds, a bainite-martensitic outer layer structure, and optimization of temperature conditions. This provides high hardness, heat resistance, and wear resistance of the outer layer. The inner layer, made of high-plasticity materials, compensates for residual stresses and improves structural stability. The use of alloying elements (nickel, molybdenum, copper) in combination with mathematical modelling of temperature fields made it possible to reduce the number of structural defects, such as porosity and delamination while ensuring uniform connection of the layers. This is because the proposed technology combines modern approaches to alloying, heat treatment optimization, and high-tech modelling of temperature conditions during casting. A notable characteristic is the optimization of materials to withstand elevated mechanical and thermal stresses, complemented by an advanced casting mold design that enhances interlayer adhesion and minimizes the likelihood of defects. This facilitates the reliable performance of rolls under challenging operational conditions, characterized by elevated mechanical and thermal stresses. Compared with similar known solutions, the proposed technology increases the service life of rolls by 20–25 %, reduces repair and maintenance costs by 15–20 %, and increases the efficiency of production processes by reducing the frequency of equipment shutdowns.