Simulation of the ductile damage during the metal forming

It was shown in this paper that the damage degree is estimated by the scalar value , that is equal to 00before plastically strain and is equal to 11at the macrocracs moment. There are two criteria that describe micro damage. The value corresponds to the generation of micro voids that couldn’t be recovered by recrystallization but do not reduce the metal strength. The value corresponds to the generation of micro voids that reduce the metal strength and material longlife. The models of metal damage accumulation during pure and alternate forming also the model of metal damage recovery under the recrystallization are developed. The speciment testing at high loading parameters gives the basic equations of the ductile damage mechanics. All of that gives the method to study ductile damage during the metal forming

Ultradispersion microstructure and phase composition formation during intensive metal forming

It was shown in this paper how rate, speed and temperature of forming influence on core size, as well as influence of the cooling speed on phase composition of construction steels. Different ways of intensive deformation achievement during metal forming and in particular a flat shaped condition: equal channel angular extrusion, drawing, cross-rolling, are considered in this paper. It should be also noted that for the receipt of the required structure and mechanical properties of steel apart from the use of rational speed-temperature process parameters of forming a metal damage limit should be taken into account

Research, development and application of the innovational technology of high quality pump-compressor pipes production from sections

The innovational technology of high-strength, cold- and corrosion-resistant pump-compressor pipes from sections was developed. It includes the reduction process inside three-high stand of screw rolling before piercing in the «80» pipe-rolling mill line in OAO SinTZ. The special attention is paid to the questions of fine-grained steel production and final tubes quality. It is shown that new technology is efficient from the point of tube production of high level mechanical properties

Modeling of "groove" rolling defect on internal surface of pipes at lengthwise rolling

The research has been conducted in pipe forming at rolling off by lengthwise rolling mill with stub mandrel; the patterns of change in dimensionless parameters were determined, which characterize deformation in side angle depending on http://www.multitran.ru/c/m.exe?t=424995_2_1elongation ratio. The model of formation of lengthwise groove on internal surface of pipes has been proposed

Improvement of manufacturing technology for thin-walled pipes made of copper alloys

Thin-walled pipes made of copper alloys - the brass grades L96, L68, L63, LANKMc; the bronze grade BrOF (the GOST state standard) are of great demand in aircraft, shipbuilding, automotive, defense, diesel and instrument-making industries. Pipe diameter ranges between 4.0 and 20 mm, and wall thickness is in the range from 0.1 to 0.6 mm. The manufacture of these pipes using traditional technological schemes is characterized by high labor input and low stability in providing quality characteristics, such as dimensional accuracy, the presence of surface defects and the level of mechanical properties. This study presents scientific evidence, new technological schemes developed for manufacturing pipes made of copper alloys with the use of the equipment and technology of multiple drawing on a long movable mandrel and results of their adoption at Revda Non-Ferrous Metal Processing Works JSC. © 2018 Trans Tech Publications, Switzerland.The study was made within the basic part of the state job in the field of scientific activity No. 11.9538.2017/BP; it was supported by Act 211 of the Government of the Russian Federation (agreement No. 02.A03.21.0006)

Distortion of the depression on the rear of the blank in broaching

When using continuous-cast billet in pipe rolling, it is expedient to roll the billet prior to broaching, so as to improve the structure and properties of the steel. To that end, a three-high screw-rolling mill for billet reduction has been installed at the TPA-80 pipe-rolling unit at OAO Sinarskii Trubnyi Zavod. Introduction of the new process was associated with increase in the rejection rate on account of indentations in the pipe. These indentations may be attributed to the depression formed at the rear of the billet in reduction and the subsequent formation of metallic semicircles on broaching; the semicircles break away and enter the deformation zone. The sources of the indentations on the rolled pipe are investigated. The broaching of the billet on a screw rolling mill is mathematically simulated. Recommendations are made with a view to reducing the surface defects on pipe produced by the TPA-80 unit with a reduction mill. © 2013 Allerton Press, Inc

Cooperation of the basic educational universitiy program and personnel preparation corporate system at the metallurgical enterprise

Повышение качества подготовки выпускника университета в значительной степени зависит от согласованности учебного процесса в университете, производственной практики на предприятии, формулировки и выполнения выпускной работы бакалавра. Важное значение для адаптации выпускника вуза на предприятии имеет корпоративная система послевузовской подготовки персонала. В докладе рассмотрены основные этапы разработки компетентностной модели бакалавра, экспертные оценки знаниям, приобретенным в университете, а также формы повышения квалификации на металлургическом предприятии.Preparation quality improvement of the university graduates to a great extent depends on coordination of educational process in the university, production practice of the enterprise, wording and execution of final Bachelor work. Personal preparation corporate system is of great importance for university graduate adaptation at the enterprise. Basic stages of elaboration of Bachelor competent model, expert valuation of knowledge, acquired in the university, and methods of qualification improvement at the metallurgical enterprise are considered

Effect of stress-strain state during helical rolling on metal and alloy structure and ductility

A working hypothesis is proposed for the mechanism of the effect of deformation regimes on granular structure and phase fineness governing an increase in ductility for silumins and low-alloy steels. In particular, an alternating nature of deformation during helical rolling (HR) provides a reduction in grain size by a factor of 5-6 compared with longitudinal rolling. For hypereutectic silumins with HR it is possible to obtain a polygonized subgranular structure, to increase α-solid solution grain and silicon crystal fineness, giving them a globular shape, and thereby provide a capacity for treatment under pressure. An important role in increasing deformation capacity of silumins is played by the new technology of melt modifying treatment and optimum temperature-rate deformation regimes. © 2013 Springer Science+Business Media New York

DECOLOURATION WITH ASCORBIC ACID UNDER EXTERNAL INFLUENCES OF METHYLENE BLUE

The present work is devoted to the study of the enzymatic activity of thiazine dyes under external action. Discoloration of methylene blue with ascorbic acid under external infl-ence. Experimental data are obtained for the dependence of the decolorization reaction rate on the mixing rate