No abstract

The thermal regime of rolling in the finishing block of stands and the cooling path after rolling largely determines the mechanical properties of the wire rod. One of the main challenges that must be addressed in the cooling design phase is reduction of temperature non-uniformity over the cross section of a wire rod. The use of adjustable cooling allows getting closer in finishing rolling mill to the regimes of the controlled rolling, thermo mechanical processing and two-phase rolling, which greatly extend the capabilities of the mill in the obtaining of high consumer properties of products. The paper presents the theory and experimental analysis of controlled cooling after rolling in the finishing rolling mill, with the aim to rise temperature heterogeneity over the cross section of the wire rod.

The article pesents the drawing process of the circular cross-section rod. The mechanical model of plastic deformation in the process of wire drawing is represented by the regularities of yielding of metal at the level of forward flow during the rolling based on theoretical solutions proposed by A. I. Tselikov. The method for determination of drawing forces was probed about by decomposing it into two problems of planar deformation and the superposition of these solutions. The results of the theoretical solution of wire drawing task were used to determine the coefficient of friction during the deformation of low carbon steel in diameter 5.5 mm by means of comparison with the known experimental results of the wire drawing efforts. Satisfactory results were obtained for evaluation of frictional forces during deformation under high plastic deformation zone conditions. The obtained values of friction coefficients can be used to solve the wire drawing tasks and under conditions of a high hearth of plastic deformation as well.

The article is devoted to the study of mechanical properties of pipe steels after rolling on a broadband hot rolling mill. Using the methods of mathematical statistics, a close pair correlation between all the characteristics of the mechanical properties of hot-rolled sheet pipe steel is revealed. The results are obtained in production practice, they create additional opportunities to verify the results of expensive mechanical tests of pipe steels in order to reduce the cost of testing and improve the reliability of the results of their evaluation.

The article is devoted the experimental studies of deformation and temperature parameters of rolling the pipe steel on the rolling mill 5000 PJSC “MMK”. Knowledge of the regularities of the change in the surface temperature of work piece during hot rolling under the conditions of thermo mechanical deformation processes is of great theoretical and practical importance. The temperature conditions determine the energy and force parameters of rolling, as well as the mechanical properties and microstructure of the finished products. The experimental rolling was carried out in two stages: roughing at 6 passes at a temperature of 1050-900 ° C and finishing at 18-20 passes at a temperature below the start of the phase transformation of 900 ° C. The finishing rolling has been carried out in a two-phase region at the stage of polymorphic transformation in the steel. Significant differences in the nature of temperature changes at different stages of rolling are revealed.