Metal Rolling Research Articles

Determining the velocity of a moving rod and the thickness of its coating using natural frequencies of flexural vibrations

Research has been performed on natural transverse vibrations of a portion of a constant length in a straight thin coated rod moving along the neutral line of a non-deformed state. The movement takes place between two rigidly fixed coaxial guides (clamps), the distance between them equalling the length of the rod moving portion. The longitudinal force is assumed to constantly act along the neutral line. It has been found that a decrease in the natural frequencies of flexural vibrations of the rod occurs with an increase in the velocity parameter. It is also shown that a decrease in the natural frequencies of flexural vibrations of the rod occurs with an increase of the coating thickness. Using two frequencies of flexural vibrations, we can determine the velocity parameter of the moving rod and the thickness of its coating. The results of the research work can find technological use in the problems on dynamics and strength of machines and mechanisms in manufacturing the coated products: in textile industry, wire manufacturing process, metallurgy (especially for rolling metal bars and strips), wire drawing, plastic products and paper rolls manufacturing and can be used to determine the velocity and the coating thickness of a moving rod, strip or wire using two frequencies of flexural vibrations.

Sequential extraction of uranium metal contamination

Samples of uranium contaminated dirt collected from the dirt floor of an abandoned metal rolling mill were analyzed for uranium using a sequential extraction protocol involving a series of five increasingly aggressive solvents. The quantity of uranium extracted from the contaminated dirt by each reagent can aid in predicting the fate and transport of the uranium contamination in the environment. Uranium was separated from each fraction using anion exchange, electrodeposition and analyzed by alpha spectroscopy analysis. Results demonstrate that approximately 77 % of the uranium was extracted using NH4Ac in 25 % acetic acid.

Determining the frictional force in the rolling of metal

The frictional force in the rolling of metal may be determined by measuring the current and shaft speed of the motor in idling. An approximate formula is proposed.

클래드강 적용을 위한 선급용 강재의 열처리 특성 평가

Abstract Clad steel has good corrosion resistance and mechanical properties arising from the hot rolling of dissimilar metals, such as carbon steel and stainless steel. However both good corrosion resistance from the cladding plate material(stainless steel) and mechanical properties from the base plate material (carbon steel) are difficult to obtain because the different steels display opposite behaviors during the cladding process. In order to make clad steel for application in the hulls of ships, proper materials selection and heat-treatment conditions are necessary. In this study, mechanical properties of base plate materials with different chemical composition were evaluated according to heat condition of cladding plate material.

Analysis of Long-Term in-Service Degradation of the Shukhov Tower Elements

The condition of old and repair steels of the Shukhov tower elements that were in service for ~110 and 70 years, respectively, was analyzed. They were assessed with several mechanical characteristics: hardness, static and impact strength, and plasticity. Both steels are shown to exhibit extra low hardness and brittle fracture resistance, which cannot be explained only by the quality of rolled metal of that time, with lower mechanical characteristics of old steel. It was assumed that in-service degradation of steel properties took place due to the evolution of scattered damage. Larger elongation of old steel at lower hardness and impact strength also points to this fact. It was also found that strength and plasticity of both steels, determined in the medium of synthetic acid rain, were lower than in air. The presence of in-service damages in the bulk of the metal was confirmed fractographically, in the case of possible hydrogen absorption by the specimens from the medium, they initiate brittle fracture in the central part of their cross-section.

Sheet Metal Rolling of Molybdenum: Thermo-Mechanical FEM Simulations

Metal forming simulations based on the finite element method are a frequently used tool for the prediction of the deformed shape, material state and reaction forces. The most critical prerequisite for any reliable result is a reasonable description of the constitutive behavior of the underlying material. The presented work focusses on the latter for the case of molybdenum via advanced formulations for the temperature and strain rate dependence. The quality of the results is compared for several approaches. Sheet metal rolling serves as an example application. Verification is based on comparison with data from industrial processes.

New rolling technology for streetcar girder rail

Despite the very diverse types of rails in industrial use, practically the same groove configurations may be used in rolling. However, the system used for streetcar girder rail is somewhat different. Computer simulation and industrial experiments permit the investigation of the axial-porosity distribution and assessment of the deformed state of the rolled metal in roughing and finishing. On that basis, a new rolling technology for streetcar girder rail has been developed. In the industrial research, the axial-porosity distribution in rolling with box grooves of the BD-1 roughing cell and slotted grooves in the BD-2 cell is investigated. The macrostructure is investigated on templates taken from the continuous-cast billet after the second, seventh, and ninth passes in the BD-1 and BD-2 cells. The results of computer simulation and the industrial trials are in good agreement.

A Comprehensive Evaluation of Industrial Land Intensive Use in Hubei Province Based on Typical Industrial Enterprises

Here, we used Bayes methods to evaluate land use intensity in 365 typical industrial enterprises across nine manufacturing industries in Hubei, China and calculated the potentiality of enterprises with moderate and low intensive land use. We did this by constructing an evaluation index system of intensive land use for industrial enterprises comprised of four sub-objective layers including land use structure, land use intensity, land input and land output, and nine element layers. We found that among 365 enterprises, 82 enterprises use land intensively, accounting for 22.47% of our sample; 215 enterprises use land moderately or have low use, accounting for 58.90% of our samples. Enterprises with intensive use tended to be metal smelting and rolling processing industries and communication equipment, computer and other electronic equipment manufacturing industries. Enterprises with moderate and low use tended to be from the special equipment manufacturing industry, pharmaceutical manufacturing industry and chemical raw materials and chemical industry. The potential area for enterprises with moderate and low land use is approximately 865.70 ha and accounts for 42.38% of total current land approved, indicating that their potentiality for intensive use is large.

Grain size effect on springback behavior in bending of Ti-2.5Al-1.5Mn foils

The precise bend forming of metal foils is difficult, mainly because that the springback behavior cannot be easily controlled. In order to investigate the springback behavior in bending of metal foils, roll bending and pressure sizing tests were conducted on Ti-2.5Al-1.5Mn foils in this study. It has been observed that the springback behavior has a close correlation with the thickness to grain diameter (T/D) ratio and crystallographic texture. A certain critical T/D ratio value is observed, which divides the variation trend of the springback behavior into two different parts. Stress distribution is disturbed in specimens with small T/D ratio, which leads to large scatter of springback angle after unloading. Pressure sizing process can change the state of stress distribution of deformation region and it is a useful process to reduce the amount of springback angle and the scatter in bending of metal foils by controlling the sizing repetitions, sizing force, holding time and punch speed. Based on these findings, a micro scale honeycomb structure is successfully manufactured.

ANALYSIS OF THE GLOBAL STEEL PRODUCT ANALYSIS OF THE STEEL-THE GLOBAL PRODUCT OF FERROUS METAL PRODUCTION

The article presents analytical results of the technical level in production of steel, structure and trends in its output. It is established that in spite of positive shifts the domestic metal production remains inferior to the world level. Dynamics of the Russian steel industry development differs from the world trends. Trends and structure of the Russian export don’t match the opportunities arising from joining the WTO. The Russian steel companies are pushed out of the high technology products market outside Russia and on the domestic market as well. The article shows that the OKDP and OKP Russian classifiers make it difficult to obtain the objective information concerning the statistical index “ready rolled ferrous metal”. The procedure is described how the index can be specified. and precised. To improve the structure of management in steel production a special indicator of the metal products processing depth level is proposed. The essence of proposed measure – it shows the share of roll-products in the whole volume of exported products. The method is described how to compare the technology level of the Russian metal industry, this value being substantially inferior against the world best.

INVESTIGATION INTO THE INFLUENCE OF THE MODES OF COLD ROLLING AND THERMAL TREATMENT ON THE MECHANICAL PROPERTIES AND STRUCTURE OF THE SHEETS MADE OF BRKH1TSR CHROMIUM – ZIRCONIUM BRONZE

The results of the investigation into the influence of thermomechanical treatment modes on the structure and anisotropy of mechanical properties of sheets made of the BrKh1Tsr chromium–zirconium bronze for the subsequent fabrication of current leads from them by bending. Thermomechanical treatment included quenching from 980 °C into water, cold rolling with various degrees of drafting (16 and 46 %), and age hardening at 475 °C for 3 h. Empirical dependences of ultimate strength and yield point as well as relative elongation of the sheets made of the BrKh1Tsr bronze on the degree of drafting during rolling are determined based on the results of tests for mechanical properties. It is established that the anisotropy of the rolled metal properties is insignificant and varies weakly at various treatment stages. The average grain size in the samples after various treatment varies insignificantly and constitutes 41,88–47,50 μ m.

Application of water jet description on the de-scaling process

The paper is dealing with application of theoretical equations derived for rock disintegration onto materials with similar behavior—thick scales on hot metal rolling slabs. Penetration of water jet through a hot, rock-like material (e.g. scale) and work of the steam bubbles emerging from the water jet on the boundary between the scale layer and the hot metal material are described by a set of appropriate equations. The model is applied on the fan jets used for de-scaling process, and it provides both the qualitative and the quantitative results. These results make possible to determine the depth of penetration of water jet into the material of the scales and calculate the sizes of pieces of the disintegrated scales. Both mechanisms of water jet acting on scales, mechanical penetration to a certain depth in the material and the formation of steam bubbles inside the material, create mechanical stresses in the material of scales, especially the tensile and the shear ones. Pieces of scales are separated due to exceeding the limits of the stress and strain in the material of scales. The presented analytical equations describing the process in a simple way yield the quick and apprehensible calculation of applicable results. It is an alternative to solution of a rather complicated set of differential equations describing the mass and heat flow. The proposed theoretical base runs with technical factors and properties that can be obtained from tables or analogies with other materials or processes. The typical water pressure range of rolling mills is 16–24 MPa, the equivalent diameter of the applied water nozzle is 2 mm, the average traverse speed of the rolling slab is set to 1 m s−1, and the mean stand-off distance of the nozzle from the steel slab surface is 150 mm. Calculated depth of penetration into scales is ranging from 5 to 18 mm for these parameters, while the real thickness of scales lies between 1 and 7 mm. Simultaneously, the calculated length of the peeled layer in the direction of the jet movement ranges from 30 to 70 mm and the cutting width determined from the jet shape and the stand-off distance is 80–120 mm. Therefore, the calculated size of the scale debris is 30 × 80 mm for layers thicker than 5 mm and 70 × 120 mm for the ones thinner than 2 mm. These theoretical values correspond with sizes of real scale debris picked at the rolling mill.

Numerical Treatments of Slipping/No-Slip Zones in Cold Rolling of Thin Sheets with Heavy Roll Deformation

In the thin sheet cold rolling manufacturing process, a major issue is roll elastic deformation and its impact on roll load, torque and contact stresses. As in many systems implying mechanical contact under high loading, a central part is under “sticking friction” (no slip) while both extremities do slip to accommodate the material acceleration of the rolled metal sheet. This is a crucial point for modeling of such rolling processes and the numerical treatment of contact and friction (“regularized” or not), of the transition between these zones, does have an impact on the results. Two ways to deal with it are compared (regularization of the stick/slip transition, direct imposition of a no-slip condition) and recommendations are given.

Forming Compound Parts of Metal / Plastics by Rolling-Extrusion

The technology of forming metal / plastics compound parts combined metal rolling, plastics extrusion and the bonding of metal and plastics were introduced. On compound forming, the principle on adhesion interface and the purpose and method of surface treatment on sheet metal were analyzed. The experiments on compound forming of zincked sheet metal / TPO were progressed as a example.

MATHEMATICAL MODELING OF THE STRESS-STRAIN STATE OF THE METAL ROLLING IN BAR CALIBERS

With the use of specialized software DEFORM 3D the stress-strain state of the metal rolling in a simple form of high-quality caliber has been investigated. As applied to rolling conditions in box, rhombus and oval calibers it has been found interconnection between the stress-strain state of the metal in the volume of the deformed workpiece and the passage of the surface layers of the metal. With the use of the data a new calibration of light-section mill rolls 250-2 of JCS “Evraz ZSMK” has been developed, the implementation of which has improved the quality of the surface of the rolled section.

The effect of roll with passive segment on the planetary rolling process

In three-roll planetary rolling process, there is secondary torsion phenomenon that may lead to rolling instability. This article proposed a new idea to alleviate the secondary torsion phenomenon by dividing the secondary torsion segment out of the roll as an independent and passive one. To study the performance of the roll with passive segment, the three-dimensional finite element models of planetary rolling process using actual roll or new roll with passive segment involving elastic–plastic and thermal–mechanical coupling were established by the software ABAQUS/Explicit, and a series of analysis had been done successfully. The rolling temperature and rolling force of planetary mill were in good agreement with the measured results, which indicated that the finite element method would supply important reference merit for three-dimensional thermo-mechanical simulation of the three-roll planetary rolling process. Comparing the simulation results of the two models, the results indicated that the change in the roll structure had just a little influence on the metal deformation, temperature, and rolling force, but it lessened the secondary torsion deformation effectively and improved the outside roundness of the rolled tube slightly. The research provided a new idea for the roll design of three-roll planetary mill (PSW).

In vitro dissolution of uranium-contaminated soil in simulated lung fluid containing a pulmonary surfactant.

During the latter part of the twentieth century, the United States developed a highly technical nuclear weapons complex that involved workers at many facilities performing complex missions at a number of different industrial sites across the country. Now, many of these sites are being remediated to remove legacy materials including chemical and radioactive wastes. Along with remediation comes the responsibility to adequately assess risk to cleanup workers who could be exposed to any hazardous materials, including resuspended uranium dust, encountered during environmental restoration. Inhalation of resuspended uranium represents one of the exposure hazards at an abandoned former metal rolling mill where approximately 11 thousand tons of uranium metal was rolled between 1947 and 1958. Residual uranium contamination in the dirt floor of this abandoned site has been exposed to rain, ice, snow, and other environmental factors for more than 50 y. This report describes the solubility of the uranium contamination in this dirt measured in vitro using a modified recipe for simulated lung fluid that contains a pulmonary surfactant. Small (0.1 g) aliquots of dirt collected at this site were sequentially dissolved in simulated lung fluid for increasing periods of time up to 30 d. Solubility was classified according to the ICRP categories as fast, medium, and slow. Results demonstrate that the solubility designation for the uranium contamination in the dirt is approximately 50% fast, 15% medium, and 35-40% slow. There was no observed difference in solubility when a pulmonary surfactant was added to the simulated lung fluid.

Investigation into the influence of cold rolling and thermal treatment modes on the mechanical properties and structure of sheets of BrKh1Tsr chromium-zirconium bronze

The results of an investigation into the influence of thermomechanical treatment modes on the structure and anisotropy of the mechanical properties of sheets of BrKh1Tsr chromium-zirconium bronze for the subsequent fabrication of current leads from them by bending are represented. The thermomechanical treatment included water quenching from 980°C, cold rolling with various reduction ratios (16 and 46%), and age hardening at 475°C for 3 h. The results of tests made it possible to determine the empirical dependences of ultimate strength, yield stress and relative elongation of BrKh1Tsr sheets upon the reduction ratio during rolling. It is established that the anisotropy of the rolled metal properties is insignificant and varies weakly at various treatment steps. The average grain size in samples varies inessentially after various treatments and is 41.88–47.50 μm.

Smart identification of roll cages through logistics chain

Article provides research in field of automatic identification of roll cages through radio-frequency identification technology (RFID) in terms of supply chain of particular postal-logistics operators. The ambition of this work is selection of appropriate identifier type and its placement on a roll cage. A special section is dedicated to description of the technical equipment used during measurements as well as their results from MySQL database. Article deals with relationship between the orientation of the antenna RFID identifier and orientation of the reader antenna and also the placement of the RFID identifier on the metal roll cage.

A Motion-Powered Piezoelectric Pulse Generator for Wireless Sensing via FM Transmission

A motion-powered pulse generator using piezoelectric transduction is reported in this paper for wireless sensing devices. A metallic rolling ball is implemented in the prototype as an inertial proof mass excited by external motions at random low frequency. Taking advantage of the metallic proof mass, magnetic coupling can be achieved to actuate the piezoelectric cantilever by attaching tip magnets to the free end. In addition, self-synchronous switching is achieved by applying electrodes to the track of the rolling ball. A new passive prebiasing mechanism is introduced to improve the performance of the pulse generator. Both simulation and experimental results were conducted to demonstrate the improvement. Experimental results show that 76% more energy can be extracted by the prebias mechanism compared to the unbiased case. A transmission circuit based on a Colpitts oscillator was built to test the performance of the capacitor-powered oscillator, which is designed as the load of the pulse generator. By adding a voltage control component, the transmission circuit is capable of encoding a sensor signal by frequency modulation, which demonstrates the feasibility of implementing a motion-powered wireless sensing prototype based on the piezoelectric pulse generator.