Deformation Behavior of Hollow Axles With Constant Hole Diameter by Three-Roll Skew Rolling

2020 ◽  
Author(s):  
Song Zhang ◽  
Xuedao Shu ◽  
Jitai Wang ◽  
Chang Xu
Keyword(s):  
Mechanical Properties ◽  
Rolling Direction ◽  
Rolling Process ◽  
Hole Diameter ◽  
Stress And Strain ◽  
Forming Process ◽  
Processing Efficiency ◽  
Forming Quality ◽  
Material Utilization ◽  
Skew Rolling

Abstract At present, hollow axles with constant hole diameter is mainly formed by turning thick-walled hollow tubes. This method of processing has low material utilization and processing efficiency. And heat treatment is required to improve the mechanical properties of hollow axles. To improve the material utilization and processing efficiency of hollow axles with constant hole diameter during the forming process, a new processing technique, three-roll skew rolling process, is proposed to form a hollow axles with constant hole diameter in this paper. The three-roll skew rolling process is a continuous plastic forming process, which has high material utilization and processing efficiency, and it can improve the mechanical properties of the rolled parts. Firstly, combining the working principle of three-roll skew rolling and the structural characteristics of hollow axles with constant hole diameter, the forming mechanism of hollow axles with constant hole diameter by three-roll skew rolling is described. Secondly, the finite element model of the hollow axles with constant hole diameter by three-roll skew rolling is established according to the dimensions of the hollow axles with constant hole diameter, the material characteristics of the hollow axles, and the stable rolling conditions of three-roll skew rolling. The process parameters of the hollow axles are also determined. Thirdly, according to each step position of the hollow axles, the forming process of the hollow axles with constant hole diameter by three-roll skew rolling is divided into 5 deformation stages. Lastly, the stress and strain field of each deformation stage of the hollow axles was analyzed. The results show that the dimensions of the hollow axles with constant hole diameter by three-roll skew rolling are very close to the designed dimensions, which indicates that the material utilization of the rolled hollow axles is very high. Along the rolling direction, the descending step of the hollow axle is easier to form than the ascending step, and the forming quality is also better. The surface metal of the rolled hollow axles flows faster than the internal metal. Areas with large stress and strain are mainly concentrated at both ends of the rolled hollow axles. And the magnitude of stress and strain gradually decrease from the surface to the center. The hollow axles with constant hole diameter by three-roll skew rolling has a good forming quality and high forming efficiency. The hollow axles with constant hole diameter is formed by three-roll skew rolling process, which has broad application prospects.

Influences of Tensile Temperature on the Mechanical Properties of Rolled Mg-Zn-Gd Sheets with Non-Basal Texture

2015 ◽  
Vol 816 ◽  
pp. 381-386
Author(s):  
H. Yan ◽  
R.S. Chen ◽  
E.H. Han
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Tensile Deformation ◽  
Rolling Direction ◽  
Tensile Tests ◽  
Rolling Process ◽  
Basal Texture ◽  
Forming Process ◽  
Microstructure Observation ◽  
Increasing Temperature

Mg-2.0Zn-xGd sheets with non-basal texture were fabricated by common rolling process, which showed excellent ductility and formability at room temperature. In this paper, tensile tests were carried out at moderate temperature along the rolling direction and transverse direction to evaluate the influences of tensile temperature on mechanical properties and formability of the sheet. The microstructural evolution during tensile deformation was also investigated to analysis deformation mechanisms. The results showed that the elongation of the sheets increased from 57% at 373K to 253% at 573°C along the rolling direction, while the yield strength decreased with the increase of tensile temperature. The microstructure observation indicated that twining was one of the deformation modes and no dynamic recrytallization took place during deformation at 373K. With temperature increasing up to 473K, dynamic recrystallization took place and led to finer microstructure. This suggests that the formability of the Mg-Zn-Gd sheets with high ductility at room temperature could be further improved by increasing temperature up to 473K, which could refine the microstructure leading to higher strength during second forming process.

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

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2125 ◽  
Author(s):  
Janusz Tomczak ◽  
Zbigniew Pater ◽  
Tomasz Bulzak
Keyword(s):  
Metal Flow ◽  
Experimental Tests ◽  
Rolling Process ◽  
Helical Rolling ◽  
Forming Process ◽  
University Of Technology ◽  
Quality Of Products ◽  
Skew Rolling

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.

scholarly journals Microstructure Characterization and Mechanical Property of Mg/Al Laminated Composite Prepared by the Novel Approach: Corrugated + Flat Rolling (CFR)

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 690 ◽  
Author(s):  
Tao Wang ◽  
Sha Li ◽  
Zhongkai Ren ◽  
Yi Jia ◽  
Wenshi Fu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Rolling Direction ◽  
Laminated Composite ◽  
Rolling Process ◽  
Interfacial Microstructure ◽  
Rolled Sample ◽  
Novel Approach ◽  
Flat Rolling ◽  
Interfacial Intermetallic Compounds

In this paper, Mg/Al laminated composites were successfully prepared at 400 °C by corrugated + flat rolling (CFR) with reduction ratios of 35% and 25% and subsequent annealing treatments were conducted at 200–350 °C for 30 min. A two-dimensional model was established to analyze the strain distribution during the first corrugated rolling process. Simulation results indicated that severe plastic deformation was formed at trough positions, which included more numerous refined grains than in the peak positions. The interfacial microstructure and mechanical property of the flattened composites along the rolling direction (RD) and the transverse direction (TD) were investigated. The results revealed that longitudinal discontinuous and transverse continuous interfacial intermetallic compounds (IMCs) were observed of the flattened as-rolled sample. Spatial distribution was provided for the grain microstructure along the thickness and rolling direction for AZ31B magnesium alloys of the CFR as-rolled composite. Mechanical property results showed that the longitudinal ultimate tensile strength (UTS) and elongation (EL) of the as-rolled sample reached 255 MPa and 4.14%, respectively. The as-rolled UTS along TD reached 325 MPa, about 30% higher than that along the RD. After heat treatment, the anisotropy of mechanical properties remained. The microstructure evolution and mechanical properties were discussed in detail.

scholarly journals Numerical Analysis of a Skew Rolling Process for Producing a Stepped Hollow Shaft Made of Titanium Alloy Ti6Al4V

2016 ◽  
Vol 61 (2) ◽  
pp. 677-682 ◽  
Author(s):  
Z. Pater ◽  
T. Bulzak ◽  
J. Tomczak
Keyword(s):  
Numerical Analysis ◽  
Thickness Distribution ◽  
Effective Strain ◽  
Rolling Process ◽  
Forming Process ◽  
Hollow Shaft ◽  
Wall Thickness Distribution ◽  
Light Trucks ◽  
Titanium Alloy Ti6al4v ◽  
Skew Rolling

Abstract The paper describes a rolling process for a hollow Ti6Al4V alloy shaft used in driving systems of light trucks. The shaft is formed by skew rolling using three tapered rolls. The principle of this forming process was discussed stressing its universality due to the potential of applying it for forming various products by one set of rolls. The numerical analysis results (product shape progression in rolling, wall thickness distribution, effective strain, temperature and variations in loads and torques) confirm that the proposed technique can be used for producing hollow long shafts.

scholarly journals Mechanical and electrical properties of polylactic acid/carbon nanotube composites by rolling process

2018 ◽  
Vol 25 (5) ◽  
pp. 891-901 ◽  
Author(s):  
Lijun Wang ◽  
Jianhui Qiu ◽  
Eiichi Sakai
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotube ◽  
Electrical Properties ◽  
Polylactic Acid ◽  
Molecular Orientation ◽  
Rolling Direction ◽  
Rolling Process ◽  
Molecular Structures ◽  
Scanning Calorimetry ◽  
Mechanical And Electrical Properties

AbstractIn this work, the rolling process was employed to fabricate polylactic acid/multi-walled carbon nanotube (PLA/MWCNT) composites at room temperature. The effects of the rolling conditions on the mechanical and electrical properties of the fabricated composites were investigated. The evolution processes of the internal molecular structures, i.e. changes in molecular orientation and crystallinity, were examined by X-ray diffraction, differential scanning calorimetry, and density method. The results suggested that the molecular orientation improved; however, the crystallinity decreased when the rolling ratio increased. The analysis of the mechanical properties revealed that the rolled composites displayed anisotropy during the rolling process. In the rolling direction, after adding 1 wt.% MWCNTs, the tensile strength increased from 58.6 to 94.3 MPa with the rolling ratio, whereas the fracture strain sharply increased to 131.5% at the rolling ratio of 60%. In addition to the mechanical properties, electrical resistivity was also investigated; notably, this property was not significantly affected by the rolling process. Furthermore, the MWCNT dispersion and morphology were investigated by scanning electron microscopy. These findings offer a simple and effective method to fabricate conductive composites with excellent mechanical properties.

The Key Technology in Extrusion Tapping of Internal Thread

2011 ◽  
Vol 295-297 ◽  
pp. 2636-2641 ◽  
Author(s):  
Yong Yi Li ◽  
Sheng Dun Zhao
Keyword(s):  
Surface Quality ◽  
Automotive Industry ◽  
Hole Diameter ◽  
Internal Thread ◽  
Processing Efficiency ◽  
Forming Quality ◽  
Key Technology ◽  
Modern Manufacturing ◽  
Traditional Process

Internal thread processing is an indispensable procedure in manufacture, its processing efficiency and quality become more and more important in modern manufacturing, especially in aerospace and automotive industry. Compared with the traditional process of cut tapping of internal thread, the process of extrusion tapping of internal thread possesses the following advantages: without chip, higher precision, better surface quality, better continuity of metallic, greater efficient, greater strength, longer tool life. This paper firstly introduces the current research status of extrusion tapping of internal thread, elaborates the principle and characteristic of extrusion tapping, analyzes the matal plastic flow law and thread forming characteristic during tapping, then generalizes the influencing law of the key technology on thread forming quality, such as extrusion tap type, lead hole diameter, tapping speed and friction. Furthermore, puts forward some improvement approach to reduce tapping torque and enhance forming quality of internal thread.

scholarly journals A New Method of Manufacturing Hollow Shafts via Flexible Skew Rolling

2021 ◽  
Vol 2101 (1) ◽  
pp. 012010
Author(s):  
Xiaoqing Cao ◽  
Baoyu Wang ◽  
Wei Guo ◽  
Zhidong Ju
Keyword(s):  
Rolling Force ◽  
Rolling Process ◽  
Fe Model ◽  
Forming Process ◽  
Hollow Shaft ◽  
Process Adjustment ◽  
Rolling Load ◽  
Rolling Torque ◽  
Skew Rolling ◽  
Hollow Shafts

Abstract The existing rolling process of large and long axle parts, such as the cross wedge rolling (CWR) process, requires special molds and larger equipment. Flexible skew rolling (FSR) hollow shafts with mandrel is a near net-shape rolling technology which can achieve the diversified production of rolled parts without special molds. It has significant advantages such as small equipment tonnage, small die size, low rolling load, simple process adjustment, and especially suitable for multi-variety and small-batch production. This paper proposes hollow train shafts formed by FSR with mandrel. Reasonable parameters were selected for experiments, and the forming process was calculated by finite element (FE) software. The experimental results are consistent with the simulation results, indicating that the FE model is reliable. The rolling force and rolling torque are analyzed by simulation. Finally, the microstructure of different positions of the rolled-piece is analyzed, and the microstructure of the rolled part is refined. It is provide a feasible scheme for the rolling of large hollow shaft parts.

Effects of thread rolling processing parameters on mechanical properties and microstructures of high-strength bolts

2020 ◽  
Vol 62 (10) ◽  
pp. 1017-1024
Author(s):  
Serkan Aktas ◽  
Yasin Kisioglu
Keyword(s):  
Mechanical Properties ◽  
Low Carbon Steel ◽  
High Strength ◽  
Rolling Process ◽  
Processing Parameters ◽  
Industrial Applications ◽  
Low Carbon ◽  
Forming Process ◽  
Cold Forming ◽  
Thread Rolling

Abstract Bolt production with a grade of 10.9 class quality made from AISI4140 material with a low thread rolling index is usually implemented in accordance with the thread rolling method (cold forming) in industrial applications. In this method, the effects of die revolutions and multiple passes are unknown in the thread forming process as the devices are usually operated with respect to geometrical dimensions but not the mechanical properties and microstructures of the material. In the literature there are few studies on microstructures of low-carbon steel having a higher thread rolling index in bolt production. This study experimentally examined the effects of the processing parameters on the mechanical properties and microstructures. Parameters such as forming speed and single or multi-pass influences were considered in the production of M12 × 1.75 and M20 × 2.5 fasteners widely used in industrial applications. The experiments identified the behavior of the mechanical properties, microstructures and micro-hardness of the AISI4140 material at two forming speeds (rpm) and three passes in the thread rolling process. Thus, significantly sensible outcomes as a function of processing parameters were obtained considering the thread strength viewpoints.

The Analysis of the Stress and Strain in Skew Rolling

2012 ◽  
Vol 538-541 ◽  
pp. 1650-1653 ◽  
Author(s):  
Hai Bo Yang ◽  
Li Jie Zhang ◽  
Zheng Huan Hu
Keyword(s):  
Three Dimensional ◽  
Element Model ◽  
Rolling Process ◽  
Stress And Strain ◽  
Workpiece Material ◽  
Center Edge ◽  
Dimensional Finite Element ◽  
Helical Groove ◽  
Three Dimensional Finite Element ◽  
Skew Rolling

In this paper, three-dimensional finite-element model for the skew rolling (helical-groove rolling) process has been used to characterize the workpiece material stress,strain and deformation behavior. Particular attention has been paid to representative cross section and the center, edge and mid-radius points of the billet

Microstructure and Mechanical Properties of Multi-Pass Warm Rolled Ti-6Al-4V Alloy of Different Microstructures

2016 ◽  
Vol 716 ◽  
pp. 871-876
Author(s):  
Yong Xu ◽  
Xiang Jie Yang ◽  
Dan Ni Du
Keyword(s):  
Mechanical Properties ◽  
Rolling Direction ◽  
Rolling Process ◽  
Warm Rolling ◽  
Strengthening Effect ◽  
Test Results ◽  
Microstructure And Mechanical Properties ◽  
Rolled Specimen ◽  
The Difference ◽  
Conventional Rolling

In this investigation three kinds of raw microstructure Ti-6Al-4V alloys were studied using two directional rolling on a conventional rolling mill. The effect of deformation on microstructure and mechanical properties has been attempted. Microstructural observation indicated that the size of the lamellar/equiaxed α grain was sharply decreased to submicro after multi-pass warm rolling. Tensile test results showed that the multi-pass warm rolling process was found to have a remarkable strengthening effect. The ultimate tensile strength and yield stress were increased by more than 10% and 25% respectively compared with unidirection rolled specimen, and the elongation has been increased by more than one times, and the maximum is up to 1.58 times. Meanwhile, the difference of the strength and elongation between in rolling direction and in transverse direction has been greatly reduced.

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