EVRAZ (Russia)

The article touches upon the problem of inconsistencies and insufficient accuracy of quantitative methods applied in analyzing mergers and acquisitions. The authors point out that the criteria for the effectiveness of the concluded deals used by the majority of researchers do not conform to the real factors which are not taken into consideration by companies’ top managers when making decisions about a deal. This results in the gap between theoretical developments and their practical application and also limits the implementation of scientific results in practice. The authors study and identify the main disadvantages of the most common analysis methods: Cumulative Abnormal Returns, or CARs, Buy and Hold Abnormal Returns, or BHAR, and also, they suggest hypotheses of medium-term profitability and long-term payback illustrating the criteria of predicting the success of mergers and acquisitions from the viewpoint of management. The authors have developed new approaches to statistical analysis of the market of mergers and acquisitions that allow to identify the deals the results of which differ significantly from the average in one direction or another. Further development and empirical testing of the suggested approaches can provide for the introduction of new techniques of evaluation of effectiveness of mergers and acquisitions, as well as for creation of sectoral and universal recommendations for top managers of the buyer companies on their basis.

Timely and full tapping of liquid smelting products is an important condition for forcing the blast-furnace process. Unstable tapping of iron and slag leads to fluctuations of the liquid level in the hearth, changes in the charging rate, and fluctuations in the time the burden stays in the blast furnace. This, in turn, affects the thermal state and the composition of the liquid products. The ratio of tapped slag weight to the hot metal weight is determined by the physical properties of slag and the length and diameter of the taphole. An analysis of the operation of the EVRAZ NTMK blast furnaces revealed substantial fluctuations of this ratio. When the volume of tapped slag is 340 to 360 kg per ton of pig iron, the slag/metal weight ratio is between 200 and 850 kg per ton of pig iron. The objective is to analyze the causes of unstable tapping and the effect of the instability on the furnace performances using the laws of fluid mechanics. It is assumed that the melt flow in the taphole is stratified. The effect of the slag properties and the dimensions of the taphole on the velocity of the melt and, hence, on the slag/metal weight ratio in the taphole is studied. Since the velocity of the melt depends on its physical properties, a mathematical model was developed to assess the slag/metal weight ratio from the viscosity of the slag and the dimensions of the taphole. The results of modeling are validated against the industrial data acquired by the EVRAZ NTMK. It was established that an increase in the tapped slag/metal weight ratio leads to worse performance and lower vanadium recovery from pig iron.

We develop a technology of assembling of composite mill rolls for the universal stands of the rail and structural steel shop at the JSC “EVRAZ ZSMK.” The proposed technology is based on the method of thermal shrink-fitting, including the application of bandage made of cast iron. The investigations are carried out to determine the optimal temperature and time parameters of the process of assembly.

We presented the results of scientific and practical investigations of the technology of rolling of asymmetric rail sections, namely, of point and wing rails, performed on a universal rail and structural steel mill. The detected disadvantages are described according to the initial calibration and the causes of formation of the surface defects in the course of rolling of these profiles are established. The results of the performed analysis made it possible to develop calibrations for the analyzed asymmetric rail sections with evaluation of the stressed state of the metal in the course of rolling.

Long multiturn coiled reinforcement may be produced by drawing without torsion. It offers several benefits over existing Vr-1 reinforcement. The influence of the roller inclination and the number of helical turns on the drawing force is studied. The mechanical properties of a four-turn helical profile are compared with those of Vr-1 reinforcement (diameter 4 mm).

Optimization of the lining life in converters is considered. The relation between the converter productivity and the lining life is established. With long lining life, the time for lining maintenance is greatly increased, with corresponding decrease in converter productivity. The optimal lining life is calculated for the converter shop at AO EVRAZ NTMK.

The paper contains the analysis results of technological features of asymmetric rail profiles production in the conditions of a universal rail-mill, as well as the stages of the development of intensified rolling mode of switch point rails, the introduction of which allowed the productivity of the rail-and-structural steel mill to be increased and the quality of the finished rails to be improved. On the example of the operating rail-and-structural steel mill of EVRAZ ZSMK JSC the technological difficulties in the production of asymmetric rail profiles with the use of a continuous universal train are illustrated. Ways for optimization of rolling modes for asymmetric rail profiles (switch point rails are taken as an example) are shown using the developed technique for calculating the resistance to deformation of rail steels and modeling the flow of metal using modern software systems. The existing standards regulating the quality parameters of switch point rails is analyzed and the recommendations for its improvement are given.

It is possible to produce hot-rolled I-beams characterized by high strength and excellent performance. The basic chemical composition of the steel required, the corresponding smelting conditions, and the rolling technology are presented. The results of tensile tests and the impact strength of the I-beams are considered. The welding properties of the metal are assessed: the strength and cold strength of the weld joints and the susceptibility to laminar and cold cracking. The requirements on the microstructure of the I-beams to prevent brittle failure are outlined. The I-beams produced from the new steel may be used in the construction of mass-produced buildings and also in one-off structures.