O. N. FILONCHIK

The article defines the optimal equipment necessary for the repair of the body stands of apipe-rolling reduction-stretching mill. The body stand of the mill crate, made of 40X structural alloy steel, undergoes wear of the bearing seats during operation. Body stands restoration is carried out by surfacing the worn surfaces of the part with subsequent machining to the dimensions specified in the design documentation. In the process of surfacing medium-carbon steels, carbides are formed, which leads to a sharp in-crease in hardness in the zone of thermal influence, which affects the durability of carbide plates and processing accuracy. It is necessary to consider the geometric shape, dimensions, weight and material of the part while choosing equipment for repairing the body stand. Using a horizontal boring machine with a horizontal spindle performing rotational and translational movement of the axial feed, it is necessary to take into account the rigidity of the spindle, which affects the accuracy of processing, especially when restoring deep holes after surfacing with hardening surfacing materials. Bending the spindle can cause vibration and beating, which will affect the quality of the work performed. An increase in the rigidity of the machining can be achieved by using a drilling rod or by increasing the diameter of the spindle. Since it is necessary to restore deep blind holes in the repaired housing, it is impossible to use a drilling rod. In the process of work, the optimal diameter of the spindle of the horizontal boring machine was determined, taking into account the design features of the work piece.

A. I. TOVSTELEVA   In the article, the current problem of reducing the cost of pipe?rolling products, which is especially acute in the world market of metal products high competition conditions is considered. A significant share in the cost of pipe products stands at the cost of rolling tools. Reducing the cost of buying adeforming tool allows you to make considerable savings in the seamless pipes’ production. The article presents: analysis of the economic efficiency of manufacturing long cylindrical mandrels from a semi?finished product – forged billet at OJSC «BSW – management company of «BMC» holding»; development of the technological process for the production of long mandrels depending on the required size; the results on the manufacture of long cylindrical mandrels from forged billet at OJSC «BSW – management company of «BMC» holding», as well as their industrial tests in the conditions of the pipe rolling shop. A positive result of using long mandrels of the PQF mill made of forged blanks was obtained.   Read more...

E. S. SEREGINA, T. N. AYUPOV       The article examines the breaks of thin brass?plated wire for metal cord and high?pressure hoses of the “sparking” type and the causes of their formation. The wire was manufactured in OJSC “BSW”? the Management Company of the Holding” BMC “ in the conditions of steel?wire workshops. The appearance and microstructure of breaks of thin brass? plated wire of the “sparking” type are investigated. As a result of the analysis of the appearance and microstructure of the breaks, it was assumed that surface defects are formed on the brass?plated wire – billet during the welding connection in the jaws of the welding machine during annealing. To confirm this, experiments were carried out with the implementation of welded joints of brass – plated wire?blanks in wet drawing areas, the appearance and microstructure of the obtained samples of welded joints were studied. As a result of experiments and metallographic studies, the assumption was confirmed that local defects such as “cauterization from sparking” on the surface of the workpiece wire are formed during welding during the annealing operation, it was established that the cause is a violation of contact between the wire and the pressure jaws of the welding machine, wear of the pressure jaws. Photos of the defect, a description of its appearance and microstructure are given. Based on the obtained studies, a number of measures were carried out aimed at eliminating the causes of this defect. Read more...

S. S. KONOVALCHUK, I. M. LIVSHITS     In order to reduce the cost of producing metal cord in the hardware shops of OJSC “BSW” – the Management Company of the Holding “BMC”, work is underway to modernize and select materials for replaceable technological equipment. In the process of twisting the metal cord on the unwinding of the power coils of rope machines, brake devices are used, consisting of a disk and sectors (pads) fixed in a chain. The elements of the unwinding unit are in constant contact, providing the necessary tension force for unwinding a thin wire. The performance of the braking devices affects the manufacturability of the twist, the absence of breaks, the density and geometric arrangement of the wires in the twisted metal cord that meets the requirements of consumers. Due to constant contact friction at high linear speeds, the brake pads wear out, which leads to emergency operation of the equipment. The article considers the test results of the modified thin wire unwinding unit and the impact of modernization on the service life of brake pads. Read more...