A. E. Gulin

Effect of Microstructure and Mechanical Properties Formation of Medium Carbon Steel Wire through Continuous Combined Deformation

The combination of different types of deformation can create a continuous method that ensures the formation of ultrafine-grain structure in medium carbon steel wire. The method is based on drawing operation combined with torsion and bending. Tools and equipment applied in the wire and cables manufacturing are used for the implementation of this method. As a result of the combined strain effect the ultrafine homogeneous structure is formed in the medium carbon steel wire. The wire has increased strength while maintaining the plastic properties when compared with the corresponding properties after drawing.

Influence of hybrid plastic deformation on the microstructure and mechanical properties of carbon-steel wire

Since the mechanical properties of metals and alloys with ultrafine-grain structure are of great practical interest, the development of continuous methods of intense plastic deformation deserves attention. The introduction of nanostructuring methods in existing production processes is subject to numerous constraints, mainly associated with the dimensions of the machined workpiece. Continuous methods of intense plastic deformation must be introduced, with corresponding gains of expediency and productivity. The combination of different types of plastic deformation is promising. Carbon-steel wire is studied in the present work. If drawing is combined with external loading, its applicability in wire production may be greatly expanded. If drawing is combined with flexure and torsion, a new production technology may be developed for the production of ultrafine-grain components. In this approach, continuously moving wire is subjected to tensile deformation (by drawing), flexural deformation (on passing through a system of rollers), and torsional deformation. The instruments employed are versatile and compatible with existing industrial equipment. If drawing is combined with flexure and torsion, the carbon-steel wire produced are characterized by ultrafinegrain structure. This approach permits modification of the mechanical properties of the wire over a broad range, without loss of strength or plasticity.

Modern Engineering Techniques for Designing Materials with a Specified Set of Properties

In order to design new progressive technological processes for metal ware production it is necessary to use unconventional methods. It is proposed to use the main aspects of TRIZ methodology to devise the new method of carbon steel wire processing. It is suggested to combine different operations of carbon steel wire production. It allows to achieve the different combination of strength and ductile properties of carbon steel wire with one diameter and carbon content. Metallographic investigations showed that microstructure of carbon steel wire after combined deformation is uniform and can be classified as ultra fine grain one. It is proved that TRIZ methodology makes it quicker the development of new methods of metal ware production which are very perspective from the market demands.

Creating ultrafine-grain structure in high-strength bimetallic steel-copper products

The benefits of continuous deformation of carbon wire are considered. Ultrafine-grain structure may be produced in carbon-steel wire with different carbon contents, so as to obtain a distinctive combination of strength and plasticity. The mechanical properties created in carbon-steel wire permit its use as the core of bimetallic wire used in contact systems for electric trains.

Ultrafine-grain structure and properties of carbon-steel wire after complex deformation

A continuous wire-deformation method is proposed. In this method, which has been patented in Russia, continuously moving wire is subjected simultaneously to tension in drawing, to flexure in a roller system, and to torsion. Metallographic data show that ultrafine-grain structure may be formed in carbon-steel wire. Mechanical tests confirm that the properties of carbon-steel wire may be improved by such deformational treatment.

Assessment of Structure Integrity and Mechanical Properties of Carbon Steel Wire in Combined Deformation Processing

Because basic metal forming methods have reached the maximum of their manufacturing capabilities in deformation-velocity processing modes so called combined or integrated processing methods move to the forefront. The method of combined deformation processing based on drawing with bending and torsion deformation was developed. On the example of carbon steel wire it was shown that microstructure and mechanical properties can vary in a wide range depending on the process regimes. In order to estimate the probability of carbon steel wire fracture at the designed combined deformation processing the simulation complex DEFORM-3D was used. The results demonstrate that there are no areas with high concentrations of hydrostatic pressure and overestimated values Cockcroft-Latham criterion. For the developed combined deformation processing of wire by drawing with alternating bending and torsion, algorithm for the prediction of carbon steel wire microstructure and mechanical properties changing at combined deformation processing was carried out. The developed methodological approach to forecasting of formation of the structure and mechanical properties during combined deformation processing of carbon steel can be used to solve both direct and inverse problems.

Structure formation in wire

The microstructure formed in the surface layer of industrially produced steel 70 wire rod (diameter 5.5 mm), wire (diameter 4.2 mm), and thin brass-plated steel 70 wire (diameter 0.933–1.75 mm) is studied. Local surface sections with turbulent structure are identified by means of transmission and scanning electron microscopy and microhardness measurements. Those sections are associated with shear stress forming additional rotary deformation modes. With increase in the deformation, a gradient in the microhardness appears. The hardness is greatest at the surface in sections with anomalous structure. The dynamics of dislocational structure in metal with deformation is investigated. The formation of pearlite colonies in high-carbon steel is studied. The results may be used in determining the limiting deformability of wire rod and wire on drawing.

Status and Prospects of Deformational Methods For Refining the Microstructure of Bulk Materials

The current interest in obtaining metals and alloys with an ultrafine-grained structure is due to the qualitatively new level of their mechanical properties. Since an ultrafine-grained structure is formed as a result of high-rate plastic deformation (HPD), this article presents several alternative definitions of HPD. Continuous HPD methods are the methods that are of practical interest. However, several unresolved scientific-technical, technological, and organizational problems are making it necessary to resort to fundamentally new approaches to developing deformation-based methods of refining microstructural components. This article presents examples of the best-known continuous deformational methods of refining the structural components of metals and alloys. On the other hand, it is also necessary to consider that certain bulk metals and alloys with an ultrafine-grained structure have properties that limit or prevent their practical use. The results obtained from an analysis are used to determine the main avenues being pursued in the development of deformational methods of refining structural components. It is particularly important to consider the use of mini-mills, which can create technological systems based on integrated and consolidated components of modular equipment.

The Possibility of Manufacturing Long-Length Metal Products with Ultra-Fine Grain Structure by Combination of Strain Effects

It is shown that combination of strain effects leads to possessing the ultra-fine grain structure in carbon wire. The continuous method of wire deformation nanostructuring was developed on the basis of simultaneous applying of tension deformation by drawing, bending deformation when going through the system of rolls and torsional deformation on a continuously moving wire. One of the main advantages of the developed method is that various hardware devices and tools already applied for steel wire production can be used to implement this method thus simplifying its introduction to the current industrial equipment. The efficiency estimation of the developed continuous method of deformation nanostructuring was carried out using carbon wire with different carbon content. It is shown that the mechanical properties of the wire after combination of different kinds of strain can vary over a wide range. This method makes it possible to choose such modes of strain effect, which can provide the necessary combination of strength and ductile properties of carbon wire depending on its further processing modes and application.

Assessing the effectiveness of intense plastic deformation of structural carbon steel

The production of a specified ultrafine-grain structure and mechanical properties of carbon steel in intense plastic deformation is formalized. Stochastic and statistical models are considered for the description of intense plastic deformation with different degrees of information regarding the relation between the control parameters and the mechanical properties of carbon steel with ultrafine-grain structure. A new approach is developed for assessing the effectiveness of intense plastic deformation of carbon steel.