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Open access

Z. Pater, J. Tomczak and T. Bulzak

Abstract

The paper describes a new method for producing stepped rail axles. The method is based on the skew rolling process. With this method, the product is formed by three tapered rolls located every 120° on the perimeter of the billet. Positioned askew to the centerline of the billet, the rolls rotate in the same direction and with the same velocity. At the same time, they get closer together or go apart depending on the desired cross sectional reduction of an axle step. In addition, the workpiece is shifted lengthwise relative to the rolls by the translational motion of the workpiece-holding chuck. In order to verify the designed method for producing rail axles, a series of numerical simulations were performed using the Simufact. Forming v.12 simulation software. The numerical modeling enabled the determination of maps of the effective strain and temperature in the finished product as well as variations in the loads and torques during rolling. The numerical results unambiguously confirm that the skew rolling method can be applied to form parts of considerable dimensions (the modeled axles had a length of 2146 mm and their maximum diameter was 202 mm).

Open access

D. Woźniak, M. Głowacki, M. Hojny and T. Pieja

This article shows example result of computer simulations supporting production process of bearing housing of aircraft engine. Verification of both deep drawing process project and tools design were carried out using finite element models implemented in eta/Dynaform 5.8.1 system and LS-DYNA solver. Wrinkling and fracture of the material were the main phenomena subjected to the investigation on the way of numerical analysis. A number of computer simulations were carried out in aim to analyze the deformation and strain distribution in the final product, as well as to eliminate the mentioned defects. In addition the comparison of results of both industrial tests and computer simulation was done.

Open access

J. Bartnicki

This paper presents the results of numerical calculations of rolling extrusion process of a hollow hub. Simulations were made by means of software Deform 3D in three dimensional state of strain. Distributions of effective stress, effective strain and damage criterion in the rolled extruded product were analyzed. Verification of metal flow during process allowed to design tools for experimental verification in PO-2 laboratory rolling - extrusion aggregate. For these needs also process force parameters were calculated.

Open access

Z. Pater

Abstract

Skew rolling is a metal forming technique which can be used for producing stepped axles and shafts. This paper investigates seventeen cases of rolling at varying process parameters by the finite element method. As a result, it is possible to determine the effect of the forming angle α, skew angle Θ, linear velocity of the chuck, v, billet temperature, T, rotational speed of the rolls, n, reduction ratio, δ and friction factor, m, on axial load (acting on the chuck), radial load (acting on the roll in the radial direction) and torque. The results will be used when designing a laboratory stand for skew rolling which will be constructed at the Lublin University of Technology.

Open access

B. Machulec and W. Bialik

Based on the minimum Gibbs Free Enthalpy algorithm (FEM), model of the ferrosilicon smelting process has been presented. It is a system of two closed isothermal reactors: an upper one with a lower temperature T1, and a lower one with a higher temperature T2. Between the reactors and the environment as well as between the reactors inside the system, a periodical exchange of mass occurs at the moments when the equilibrium state is reached. The condensed products of chemical reactions move from the top to the bottom, and the gas phase components move in the opposite direction. It can be assumed that in the model, the Reactor 1 corresponds to the charge zone of submerged arc furnace where heat is released as a result of resistive heating, and the Reactor 2 corresponds to the zones of the furnace where heat is produced by electric arc. Using the model, a series of calculations was performed for the Fe-Si-O-C system and was determined the influence of temperatures T1, T2 on the process. The calculation results show a good agreement model with the real ferrosilicon process. It allows for the determination of the effects of temperature conditions in charge zones and arc zones of the ferrosilicon furnace on the carbothermic silica reduction process. This allows for an explanation of many characteristic states in the ferrosilicon smelting process.

Open access

A. Tofil, J. Tomczak and Z. Pater

Abstract

The paper describes cross wedge rolling with upsetting, a process in which axially symmetric parts with steps whose diameters are larger than billet diameters can be formed. Taking advantage of numerical modeling, the effect of such basic geometric parameters of the rolling process as the spreading angle, forming angle, reduction ratio, and rolling length on upsetting (defined by the diameter increase ratio) was determined. The paper also presents the results of experimental tests performed to roll a stepped shaft whose one step had a diameter half as large as that of the billet.

Open access

P. Lacki, J. Adamus, W. Więckowski and J. Winowiecka

Abstract

Despite substantial demand for drawn parts made of high-strength sheet metal (including titanium alloys) observed in the modern industry, particularly automotive and aviation, their application remains insignificant. This results from the fact that such sheet metal shows poor plasticity and its cold-forming is almost impossible. Low drawability makes it impossible to obtain even such simple shapes as spherical cups. The authors of this study developed circular sheet-metal blanks with cutouts on their perimeter. The blanks allow for cold forming of spherical cups from Ti6Al4V titanium alloy sheet metal using conventional rigid tools. The cutouts proposed in the study affect plastic strain distribution, which in turn leads to an increase in forming depth by about 30%. The numerical analysis, performed using the PamStamp 2G System software based on finite element method, was verified experimentally.

Open access

T. Pała and I. Dzioba

Abstract

The paper presents the results of two butt welded joints by conventional method. The welding process was performed using a variety of linear welding energy. The studies included experimental and computational part. In experimental studies determined the distribution of hardness and mechanical properties of the individual analyzed sections of welded joints. The data obtained were intended to determine the extent of zones in the welded joints that have certain strength characteristics. Also conducted uniaxial tensile tests of welded joints with the registration of displacement fields on the surface of specimens by means of Aramis video-system what the final result are images of strain fields map on the surface of welded joints. The resulting strain values were compared with the results of numerical computations FEM.

Open access

J. Bartnicki, J. Tomczak and Z. Pater

Abstract

This paper presents results of numerical calculations for the rolling process by means of three tools of stepped shafts from aluminum alloy 7075. Forming with the usage of tools with three different wedge spreading angles underwent analysis. In the paper, the obtained distributions of stresses, strains and Cockcroft-Latham damage criterion were given. Moreover, the influence of the wedge spreading angle on shape faults presence in the obtained product was determined. At the same time, the force parameters, which play a crucial role in the designed experiment, were analyzed.

Open access

M. Kukuryk

Analysis of Deformation and Damage Evolution in Hot Elongation Forging

The paper describes the analysis of the three-dimensional stress and strain state for the process of elongation forging of the X37CrMoV51 die steel using the finite element method. The results of simulation studies of the metal flow pattern and thermal phenomena in the hot forging process carried out in three different forging tools are reported. The results of the studies have been complemented with the prediction of the occurrence of ductile fractures during forging. The numerical analysis was performed using the DEFORM-3D program. The comparison of the theoretical study and experimental test results indicates a possibility of applying the developed model to the examination of strains and prediction of material fracturing during the hot forging of die steel.