Influence of wet wire drawing speed on the brass-plated steel cord properties

Steel cords are a reinforcing phase of the rubber-steel-canvas composite, and their properties, including strength, depend on the quality of the wires. The novelty of the work is a multi-parameter analysis of the cord production process, which showed that there is a relationship between the rheological properties of the lubricating emulsion, the friction conditions and deformation of the brass coating, and the properties of the wires and their resistance to cracking when braiding into a steel cord. It was shown that the friction conditions depend on the wire temperature and the rheological properties of the emulsion. As the drawing speed increases, the emulsion viscosity improves. The grease reaches its optimum at a specific drawing speed depending on the type of emulsion and the type of wire. Further increases in drawing speed result in an increase in temperature at the material/tool interface. This leads to a decrease in the viscosity of the emulsion and the breakdown of the lubricant film in the contact zone. Inappropriate selection of wet drawing speed contributes to a decrease in plastic properties and a reduction in the number of twists and bends of the wire, which leads not only to wire breakage at the stage of cord braiding but also to its premature breaking during the tensile test.