Billet Diameter Research Articles

Formation of concavities on the ends of parts manufactured on CNC skew rolling mills

This study investigates the problem of concavity formation on the ends of parts manufactured on CNC skew rolling mills. Numerical modeling and Taguchi method were used to determine the effects of the main parameters of skew rolling (i.e., forming angle, skew angle, reduction ratio, temperature, steel grade, dimeter ratio, velocity ratio) on the depth of concavities formed on the product ends. The simulations showed that the only parameter to have a significant impact on the concavity depth was the reduction ratio. The FEM results were then used to establish equations for calculating concavity depth and allowance for excess material with concavity. For more universality, the established equations took into account the billet diameter. The experimental validation showed high agreement between the numerical and the experimental concavity depths.

Development of a computer program for calculating the geometric parameters of the deformation zone and mill tuning parameters in the process of producing hot-rolled seamless tubes

Determining the optimal tuning parameters for a piercing mill is a labor-intensive process. There are various calculation methods available for determining the tuning parameters of a piercing mill but implementing these methods can be time-consuming. Therefore, the developed computer program for calculating the geometric parameters of the deformation zone during the piercing of round billets and the tuning parameters of the piercing mill represents an innovative tool for calculating the tuning parameters of the piercing mill. The program allows for the establishment of optimal parameter values required to achieve the desired quality and accuracy of the steel piercing process. The main functions of the program include the analysis and processing of input data, such as the billet diameter, steel grade, roll calibration, and piercing mill tools. Based on this data, the program utilizes a developed mathematical model to calcu-late the optimal tuning parameters of the piercing mill, considering the required process characteristics and the desired level of product quality. One of the key features of the program is its high accuracy and universality. It takes into con-sideration multiple factors that affect the piercing process and enables reliable production forecasting. The program has a user-friendly interface, making it convenient for both specialists and shop floor personnel in the field of hot-rolled seamless tube production. The developed computer program is a valuable tool for manufacturers and research centers involved in steel piercing. It helps improve production efficiency, enhance product quality, and reduce time and costs associated with piercing mill setup. The program represents a significant contribution to the development and improve-ment of piercing technology in industrial settings

Influence of the geometry of the tool on stress-strain state cylindrical parts with reversible surface plastic deformation

Finishing-hardening treatment of shafts and axles by reversible surface plastic deformation is considered. A finite element model of the stress-strain state of the surface layer of cylindrical parts is constructed by 3D design and computational modeling, taking into account the geometry of the tool. It has been established that a decrease in the profile radius, roller diameter, and billet diameter increases the temporary and residual stresses in the surface layer. The optimal distance between the vertices of a two-radius roller is determined, which ensures the maximum stress state while all other conditions being equal. Keywords: reversible surface plastic deformation, distance between roller vertices, profile radius, temporary and residual stresses, plastic deformation. zsa@istu.edu, nquan6799@gmail.com

Numerical optimization of billet diameter in the wide-spread and split extrusion process

The research object was the wide-spread shunt extrusion production of large-diameter thick-walled AZ31 magnesium alloy pipe with 360mm outer diameter and 10mm wall thickness. Based on the DEFORM-3D finite element software platform, the simulation study on the influence of billet diameter on extrusion pressure was carried out to provide theoretical support for the reasonable selection of equipment tonnage. The results show that the peak extrusion pressure increases with the increase of billet diameter, and the increasing speed is accelerated. By reducing the billet diameter, the peak extrusion pressure can be gradually reduced from 4800 tons to 2200 tons, and the maximum extrusion cargo can be saved by more than 50%. If 3600 tons extruder is used, the billet diameter should be less than 325mm; If 2500 tons extruder is used, the billet diameter should be less than 285mm.

Simulation of the Kinematic Condition of Radial Shear Rolling and Estimation of Its Influence on a Titanium Billet Microstructure.

The finite element method (FEM) computer simulation of the three-high radial shear rolling of Ti-6Al-4V alloy round billets was conducted using QForm software. The simulation was performed for the MISIS-100T rolling mill's three passes according to the following rolling route: 76 mm (the initial billet diameter) →65 mm→55 mm→48 mm (the final billet diameter). The change in the total velocity values for the points on the radius of the 48 mm diameter billet was estimated while passing the rolls' draft. The relative increase in the accumulated strain was estimated for the same points. Then, experimental shear rolling was performed. Grain sizes of the α- and β-phases were estimated in the cross section of the final billet at the stationary stage of rolling. The grain size distribution histograms for different phases were plotted. An area was found in the billet's cross section in which the trend of change in the total velocity of the points changed. This area represented a neutral layer between the slowing peripheral segments of the billet and the accelerating central segments of the billet. Inside this neutral layer, the limits of the cylindrical surface radius value were estimated. Experimental radial shear rolling was performed to compare the experimental rolling results (the billet microstructure investigation) with the computer simulation results. The computer simulation obtained two estimations of the radius limits: 8-16 mm (based on the analysis of the total velocity change) and 12-16 mm (based on the accumulated strain's relative increment change). The experimental rolling obtained two more estimations of the radius limits: 8.4-19.5 mm and 11.3-19.7 mm-based on the results of the microstructure investigation. It was confirmed that varying the kinematic and deformation parameters of radial shear rolling allows regulation of the thickness of the peripheral fine-grain layer and the diameter of the central coarse-grain layer of the rolled billets.

Modelling of the sheet forming while 3-roller bending process

3-roller bending process was investigated using physical modelling and computer simulation. Main technological parameters influence on the formation of tube billet diameter are present; these main technological parameters are upper roller displacement and distance between axes of bearing rollers. Complete factorial experiment was conducted using bending machine, radius of the produced tube billet was set as response function. Conditions for conducting the complete factorial experiment using bending machine and techniques of tube billet radius estimation by graphical-analytical method are presented. At that least square method and SolidWorks software were applied. Regression equations for calculating tube billet diameter conditionally upper roller displacement and distance between axes of bearing rollers were obtained. Influence of these two factors on tube billet radius formation was demonstrated. Finite element method (FEM) computer simulation of the forming process was done with respect to parameters corresponding to parameters of physical modelling experiment using bending machine. FEM computer simulation was done using QForm software. QForm simulation was realized for elastic-plastic bending in terms of two-dimensional deformation. Point tracking was applied to calculate coordinates of the points of the formed sheet and bending parameters. It allowed estimation of the neutral line location in the formed sheet when bending stage was finished. Presented results of computer simulation are figures with trajectories of the tracked points; figures illustrating changing of distance between tracked points; graph of accumulated strain changing through sheet’s thickness. New criterion for neutral line (neutral surface) was proposed for sheet bending process. Results of the research can be effective when exploring Heausler AG bending equipment.

Process design and finite element analysis of multi-station two-roller cassette hot rolling for aluminum alloy 6061 wire

In this paper, a round-oval-round roller cassette wire rolling process of the aluminum alloy 6061 was studied for the process and the roller design evaluation. The elliptic groove of roller was designed for the stand of oval cross-sectional profiles. The billet diameter for this 10- stand rolling process simulation is 20mm. The diameters for the round cross-section profile stands are 16mm,12.8mm,10.2mm,8.2mm, and 6mm, respectively. The forming conditions for the CAE simulation is 400 °C for billet temperature, 0.45 for the constant shear friction factor, 20mm/s for the initial rolling speed. The CAE (Computer Aided Engineering, CAE) results had shown the maximum dimension deviation of the billet is less than 0.25 mm at the location of the roller gap and almost perfect match at the other locations. The maximum principal stress distribution on the cross section had shown a two third area was deformed under the rolling process. The CAE results had demonstrated the proposed process and die design was able to make the smaller wire with good geometrical accuracy without breaking the wire during the rolling process because of the more uniform stress distribution at the cross section of wire.

Channel Angular Pressing of the Annular Metal Billet

The article presents the developed method of channel angular pressing of the annular billets and gives the examples of hardening annular aluminum billet by channel angular pressing. The channel angular pressing is shown to result in aluminum hardening by 1.4 to 1.5 times. This increases the diameter of the annular billet.

Influence of Electrical Conductivity on Heating Power of Metal Billets in HTS DC Induction Heater

A novel high-temperature superconducting (HTS) direct current induction heater exhibits great advantages such as high efficiency and superior heating quality for non-magnetic metal billet heating process in industrial applications. An HTS induction heater of 1 MW is used in the Al press industry. The HTS induction heater injects high resistive heating power through the driving motor. The higher the resistive heating power, the shorter the heating time. The heating power is a significant parameter used to analyze the heating time and improve the production efficiency. In this study, three types of non-magnetic metal billets were analyzed, including Al, TC4 (Ti-6AL-4V), and Cu, which are widely used in the heating process in industrial applications. The experimental results of the heating of TC4 and Al billets (Φ = 220 mm × L = 1,250 mm) using an HTS induction heater were obtained. The changing trend of the heating power during heating was different. The heating power of TC4 was different from those of Al and Cu. The heating power of TC4 was much lower than those of Al and Cu. A numerical 3-D finite element method model was built to analyze the heating power. The results of the simulation and experiments were consistent with each other. The electrical conductivity of the billet is a significant material property affecting the heating power. Finally, the influence of the billet diameter on heating behavior was analyzed for the three different metal billets. Understanding the effect of electrical conductivity of important industrial metals such as Al, Ti, and Cu alloys on heating power is useful for improving metal processing technologies.

Heating Characteristics of TC4 Titanium Alloy in an HTS DC Induction Heater

Titanium andits alloyscan be heated using heavy oils, gases, resistance furnaces, liquid media, and conventional alternating current (AC) induction heaters. However, the novel superconducting direct current (DC) induction heater has several advantages over its AC counterpart in terms of heating time, efficiency, and heating quality. Therefore, it has gained remarkable success in the aluminum extrusion industry. The superconducting DC induction heaters can achieve efficiency by up to 90%, which is significantly higher than the AC induction heater (40-50%). In this study, experiments on the heating of Ti-6AL-4V (TC4) billets (Φ = 220 mm × L = 1,250 mm) using a high-temperature superconductor (HTS) induction heater were performed. A numerical 3D finite element method (FEM) model was developed to analyze the heating behavior of TC4 billets. The results from the simulation and experiments show a good agreement. Further, the radial temperature profile, heating power, and heating time were studied using the developed model. The results show that the penetration of the heating power decreases with the rotation speed. Hence a low radial temperature difference was achieved by applying an exceptionally low rotational speed on the DC induction heater, 100-500 rpm (corresponding to 1.7-8.3 Hz). We also found that heating power increased rapidly with the diameter of the TC4 billet. Therefore, the heating time could be substantially minimized by increasing the magnetic flux density and rotational speed, especially for a large billet with a diameter exceeding 300 mm. The results obtained in this study will be useful for industrial applications of Ti alloy pre-heating.

Study of the Welding Zone in Double-Layer Pipe Billets Produced by Explosion Welding

The formation of a welding zone in long pipe billets produced by explosion welding is studied in the paper. The distribution of a melt zone over the diameter of pipe billet is investigated. Melt zones mainly are formed on the ends of the sample. Their thickness increases with increasing the welding conditions. In this work, a solid interlayer of mixed composition is shown to be formed during the explosion welding of steel pipe billets (08Kh18N10T and 37G2F) with a length of 1 meter. Comparison of the data obtained for the welding zones between pipe and sheet billets showed that solid interlayers of melts were formed in pipe billets with a smaller length as compared with sheet billets. A technique for estimating the effect of shock-compressed gas on the surface of the sheets subjected to welding with the adaptation of calculations for the welding of cylindrical products was used for a theoretical estimate of the maximum thickness of melt zones in the welding zone under certain explosion welding conditions along the length of billets. The calculations showed that the geometrical dimensions and thermodynamic parameters of shock-compressed gas will increase linearly depending on the path traveled by the contact point.

Analysis of thermally driven flow pattern formation in aluminium DC casting for different Rayleigh numbers and billet diameters

The formation of final billet quality in the Direct-Chill (DC) casting of aluminum alloy can usually be a function of flow characteristics in the bulk liquid/slurry and the mushy zone. The present work has numerically studied the effect of the Rayleigh number (Ra) and the billet casting diameter on the flow pattern under the influence of thermal convection in the DC casting. The turbulence effect was approximated using the low Reynolds number Velocity Variance-Elliptic relaxation (Re v2-f) turbulence model. In the numerical scheme, the second-order upwind differencing scheme was used to discretize the combined diffusion/convection coefficients and the fully implicit scheme was employed to discretize the transient term. The solutions of the model equations were implemented in ANSYS FLUENT utilizing some user-defined function codes specifically written for the present work. The results obtained show that there is an absence of recirculating vortex for lower Ra which led to deeper sump depth. Also, an increase in the casting billet diameter deepens the flow penetration, weakens the recirculating vortex and deepens the sump depth.

Analysis of Peak Electromagnetic Torque Characteristics for Superconducting DC Induction Heaters

The efficiency of novel superconducting direct current (DC) induction heaters can be up to 80-90%. This is much higher than the 40-50% of conventional alternating current induction heaters. Induction heaters are used to preheat aluminum billets in extrusion pressing. Such devices use a driving motor to rotate the billet. A peak in the electromagnetic torque appears at low rotation speeds (of the motor). Therefore, this peak electromagnetic torque is of particular interest when designing the driving system, which is one of the main challenges for megawatt-class superconducting DC induction heaters. In this paper, the peak electromagnetic torque characteristics of different sized billets were analyzed. A numerical 3D finite element method model was built to analyze the peak electromagnetic torque and resistive heating power behavior of aluminum billets. The results obtained from simulations and experiments match well. The effect of the following five relative parameters, on electromagnetic torque and resistive heating power, were studied: billet diameter, billet length, magnetic flux density, billet material, and electrical conductivity. The peak electromagnetic torque increases nonlinearly with increasing billet diameter, up to 640 mm. The time elapsed between the peak to stable torque decreases nonlinearly with increasing magnetic flux density. The effects of billet material (copper, titanium alloy and stainless steel) on torque were analyzed and compared. These results are likely to guide more cost-effective and practical designs for the billet driving system of superconducting DC induction heaters.

Effect of process parameters on longitudinal weld seam quality of aluminum alloy profile for an automobile fuel tank protector

The aluminum alloy profile of an automobile fuel tank protector is taken as the research object in this paper, the problem of poor longitudinal weld seam quality is analyzed, and the effect of process parameters on the longitudinal welding quality is studied. The morphology of poor longitudinal weld seam is observed by optical microscopy and scanning electron microscopy. The effects of extrusion speed, extrusion temperature, and billet diameter on the welding quality of the longitudinal weld seam are studied by using K parameters to quantitatively characterize the welding quality. Simulation results show that lower extrusion speed, higher billet temperature and larger billet diameter are beneficial to improve the longitudinal welding quality. The initial extrusion process parameters are adjusted according to the rule of simulation results, and the extrusion test is carried out again. After the adjustment, the longitudinal weld seam quality is obviously improved, which is in accordance with the simulation results.

Influence of Processing Parameters on the Thread and Spline Synchronous Rolling Process: An Experimental Study

The thread and spline synchronous rolling (TSSR) process is a new developed rolling process, which can form the different profiles simultaneously in the process and can ensure the consistency of the relative position of different profiles of parts. However, the multi-meshing motions are intercoupling and the multi-deformation characteristics are intercoupling during the forming process. It can easily result in dimension overshoot, and even does not make the synchronous rolling process go smoothly. Exploring the influence of controllable processing parameters on the synchronous rolling process, especially the geometric parameters of rolled parts, is helpful to determine the parameters and control the size error for a smooth rolling process. Thus, in this paper, the effects of controllable geometric parameters and motion parameters such as billet diameter, radial feed-in speed, and rotational speed of synchronous rolling die on the TSSR process have been studied. The synchronous rolling experimental scheme was determined using an orthogonal experimental design method, and the geometric parameters of different tooth profiles of rolled parts were measured and analyzed. The experimental results indicated that: the uncoordinated meshing movement between different tooth profiles is more likely to cause tooth error of the splined section of the part; variations of the processing parameters are more likely to cause fluctuations in the size of the splined section of the part, and change of the billet diameter mainly affects the outside diameter of the threaded and splined sections, and the threaded and splined pitches are mainly affected by the motion parameters of the synchronous rolling die; the motion parameters of the rolling die should be matched and the lower rotational speed needs to match the lower radial feed-in amount per revolution; the ideal dimensional accuracy can be obtained by using an appropriate processing parameter combination, for example, the pitch error of the splined section of the part is less than 0.5 μm under one set of experimental conditions in this paper.

The Effect of Process Parameters in Helical Rolling of Balls on the Quality of Products and the Forming Process.

This paper presents selected numerical and experimental results of a skew rolling process for producing balls using helical tools. The study investigates the effect of the billet’s initial temperature on the quality of produced balls and the rolling process itself. In addition, the effect of billet diameter on the quality of produced balls is investigated. Experimental tests were performed using a helical rolling mill available at the Lublin University of Technology. The experiments consisted of rolling 40 mm diameter balls with the use of two helical tools. To determine optimal rolling parameters ensuring the highest quality of produced balls, numerical modelling was performed using the finite element method in the Forge software. The numerical analysis involved the determination of metal flow kinematics, temperature and damage criterion distributions, as well as the measurement of variations in the force parameters. The results demonstrate that the highest quality balls are produced from billet preheated to approximately 1000 °C.

Modified Cross-Wedge Rolling for Creating Hollow Shafts

Cross-wedge rolling (CWR) is an incremental forming method for producing rotationally symmetric components such as a basic shape of gear shaft or a preform before impression die forging.In CWR the material of a solid cylindrical billet is redistributed in axial direction while the billet diameter is reduced. Conventional CWR cannot be used to produce hollow shapes. This paper presents a modified CWR process, which enables the manufacturing of hollow shafts and thus provides a technological base for utilizing the large potential of the method regarding cost and resource efficiency in mass production.The method introduces two mandrels which act concurrently with the tooling wedges in an elaborate kinematic system. During processing, the generated shear stresses induce fracturing located along the billet axis. The actively driven mandrels use the fracture and penetrate axially into the workpiece.This paper provides a description of the basic principle of this innovative method and discusses the complex interaction between tool geometries, kinematic system and processing parameters.

Studies on Suspension Property of Sugarcane Components

Although China has a rapid growth in sugarcane yield, the level of mechanized harvesting of sugarcane is far lower than that of Brazil and Australia. One of the main reasons is that the high impurity rate of mechanized harvested canes cannot meet the requirements of sugar mills. The theoretical basis of separating impurities from harvested canes using extractors is that sugarcane components have different aerodynamic characteristics. Thus in this study, six single factor tests were conducted on the extracting test platform to examine the suspension property of cane components. It investigated relationships between suspension velocity and the length and diameter of sugarcane billets, the quality and length of sugarcane tops, the length and width of sugarcane leaves, respectively. Test results showed that the length of sugarcane billet has no significant effect on its suspension velocity, however, the suspension velocity increased with the increasing billet diameter. Both of the suspension velocities of light and heavy sugarcane tops increased with the increasing lengths. The suspension velocity of sugarcane leaves increased with the increasing lengths, on the contrary, it decreased with the increasing widths. In addition, by comparing the suspension velocity range of each component, it can be found that the cane leaves are the easiest to be removed, the light sugarcane tops take the second place, and the heavy tops are the most difficult to be removed. Since the suspension velocities of the sugarcane tops and billets overlapped, when the fan speed of extractors was increased to remove the heavy tops, the billet losses would be increased which affected the benefits of the sugarcane growers. Therefore, in the future, researchers should focus on how to separate the heavy tops from billets effectively for improving the impurity removal performance of sugarcane harvester.

Role of the scaling factor in the process of SHS extrusion based on the example of a TiC + Co system

The effect of the scaling factor (the influence of the height and diameter of the initial cylindrical billet) on the temperature distribution in a material and on the completeness of the extrusion of long samples obtained the method of self-propagating high-temperature synthesis (SHS) extrusion has been theoretically studied. A numerical analysis has been carried out based on the mathematical simulation of the thermal conditions of the SHS extrusion process. It has been shown that the change in the scaling factor significantly affects the length and quality of extruded rods due to the uniformity of the temperature field. It has been found that there is a limiting value for the diameter of the initial billet above which material is hardly squeezed out of the camera.

Numerical and Experimental Study of Producing Two-Step Flanges by Extrusion with a Movable Sleeve

Abstract The paper presents a new metal forming process for producing two-step external flanges on hollow parts. With this method, the flange is extruded by a movable sleeve, which moves in the opposite direction to the punch. This reduces the phenomenon of buckling of the tube wall, which allows extruding flanges with relatively large volumes. The new method was applied to produce a two-step flange on the end of a tubular billet made of 6060 aluminum alloy. This cold metal forming process was designed based on numerical simulations and experimental tests. The effect of the basic technological parameters on metal flow was investigated and limitations of the process were identified. The experimental results confirmed the possibility of forming a two-step flange with a diameter that is approximately twice as big as the external diameter of the tubular billet.