scholarly journals A Model of Surface Residual Stress Distribution of Cold Rolling Spline

2017 ◽  
Vol 2017 ◽  
pp. 1-21 ◽  
Author(s):  
Z. H. Ding ◽  
F. K. Cui ◽  
Y. B. Liu ◽  
Y. Li ◽  
K. G. Xie
Keyword(s):  
Residual Stress ◽  
Cold Rolling ◽  
High Reliability ◽  
Processing Parameters ◽  
Multiple Regression Model ◽  
Tooth Profile ◽  
Contour Method ◽  
Forming Process ◽  
Surface Residual Stress ◽  
Cold Roll

Residual stress is an important parameter in the evaluation of the performance of a cold rolling spline surface. However, research on cold rolling spline is rare. To improve the surface property of a spline, an involute spline is selected as the object of this study. The contour method for determining cold roll-beating residual stress involves measuring the force spatial distribution, performing a statistical analysis of the experimental results, establishing the parameters for the tooth profile for different positions (dedendum, pitch, and addendum) of residual stress, and determining the effect of pressure on the relationship between stress and the depth of the cold roll-beating. A response surface method is used to establish the spline tooth profile of the dedendum, pitch, and addendum of the residual stress and different depths of the stress layer to obtain the parameters of a multiple regression model and perform a comparative analysis of the experimental and prediction results. Research indicates that the prediction results have high reliability. The establishment of this model has important guiding significance to control the residual stress in the cold roll-beating forming process, optimize the cold roll-beating processing parameters, and improve the surface properties of cold rolling spline.

scholarly journals Analysis of Metal Flow Behavior and Residual Stress Formation of Complex Functional Profiles under High-Speed Cold Roll-Beating

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Fengkui Cui ◽  
Yongxiang Su ◽  
Kege Xie ◽  
Wang Xiaoqiang ◽  
Xiaolin Ruan ◽  
...  
Keyword(s):  
Residual Stress ◽  
Plastic Flow ◽  
High Speed ◽  
Metal Flow ◽  
Tooth Profile ◽  
Stress Generation ◽  
Functional Profile ◽  
Forming Process ◽  
Cold Roll ◽  
Stress Formation

To obtain a good surface layer performance of the complex functional profile during the high-speed cold roll-beating forming process, this paper analyzed the metal plastic flow and residual stress-formed mechanism by using a theoretical model of the metal flow and residual stress generation. By using simulation software, the cold roll-beating forming process of a spline shaft was simulated and analyzed. The metal flow and residual stress formation law in the motion were researched. In a practical experiment, the changes in the grains in the spline tooth profile section and the residual stress distribution on the tooth profile were studied. A microcorrespondence relationship was established between the metal plastic flow and the residual stress generation. The conclusions indicate that the rate at which the metal flow decreases changes gradually at different metal layers. The residual stress value is directly related to the plastic flow difference. As the roll-beating speed increases, the uneven degree of plastic deformation at the workpiece surface increases, and the residual stress in the tooth profile is generally greater. At the same roll-beating speed, the rate change trend of the metal flow decreases gradually from the surface to the inner layer and from the dedendum to the addendum. The residual stress distribution on the surface of the tooth profile decreases from the dedendum to the addendum. These findings provide a basis and guidance for the controlled use of residual stress, obtaining better surface layer quality in the high-speed cold roll-beating process of the complex functional profile.

scholarly journals Investigations on Residual Stresses within Hot-Bulk-Formed Components Using Process Simulation and the Contour Method

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 566
Author(s):  
Bernd-Arno Behrens ◽  
Jens Gibmeier ◽  
Kai Brunotte ◽  
Hendrik Wester ◽  
Nicola Simon ◽  
...  
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Process Simulation ◽  
Hot Forming ◽  
Contour Method ◽  
Stress Profile ◽  
X Ray Diffraction ◽  
Forming Process ◽  
Near Surface ◽  
X Ray

Residual stresses resulting from hot-forming processes represent an important aspect of a component’s performance and service life. Considering the whole process chain of hot forming, the integrated heat treatment provided by a defined temperature profile during cooling offers a great potential for the targeted adjustment of the desired residual stress state. Finite element (FE) simulation is a powerful tool for virtual process design aimed at generating a beneficial residual stress profile. The validation of these FE models is typically carried out on the basis of individual surface points, as these are accessible through methods like X-ray diffraction, hole-drilling, or the nanoindentation method. However, especially in bulk forming components, it is important to evaluate the quality of the model based on residual stress data from the volume. For these reasons, in this paper, an FE model which was already validated by near surface X-ray diffraction analyses was used to explain the development of residual stresses in a reference hot forming process for different cooling scenarios. Subsequently, the reference process scenarios were experimentally performed, and the resulting residual stress distributions in the cross-section of the bulk specimens were determined by means of the contour method. These data were used to further validate the numerical simulation of the hot forming process, wherein a good agreement between the contour method and process simulation was observed.

scholarly journals Optimization of the Physical and Mechanical Properties of a Spline Surface Fabricated by High-Speed Cold Roll Beating Based on Taguchi Theory

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Fengkui Cui ◽  
Yongxiang Su ◽  
Shaoke Xu ◽  
Fei Liu ◽  
Guolin Yao
Keyword(s):  
Mechanical Properties ◽  
Feed Rate ◽  
High Speed ◽  
Physical And Mechanical Properties ◽  
Processing Parameters ◽  
Roll Forming ◽  
Surface Residual Stress ◽  
Spline Surface ◽  
Cold Roll ◽  
Reasonable Choice

The aim of this work is to control the physical and mechanical properties of a spline surface and achieve a reasonable choice of high-speed cold roll-beating processing parameters. The surface residual stress and surface work hardening at the indexing circle serve as the main evaluation indices of the physical and mechanical properties of the spline surface. The influence degree of the processing parameters on each evaluation index is analyzed using Taguchi theory. An optimized model for improving the Taguchi process capability index that combines Taguchi theory with entropy theory is established, and the integral process capacity index is optimized via the generalized price reduction gradient method. The results of the optimization and the verification test are implemented in a high-speed cold roll forming test for comparison. The results show that the influence of processing parameters on the physical and mechanical properties of the splash surface of the cold roll can be ordered as follows: feed rate > roll round radius > cold roll-beating speed. In addition, the spline surface physical and mechanical properties of the optimal processing parameters were obtained for the combination of a cold rolling speed of 1581 r/mm, feed rate of 42 mm/min, and roll round radius of 2 mm.

Residual Stresses Associated with the Production of Coiled Automotive Springs

2014 ◽  
Vol 777 ◽  
pp. 78-83 ◽  
Author(s):  
Andrew M. Venter ◽  
Vladimir Luzin ◽  
D.G. Hattingh
Keyword(s):  
Residual Stress ◽  
Shot Peening ◽  
Stress Concentrations ◽  
Forming Process ◽  
Surface Residual Stress ◽  
Process Stage ◽  
Residual Stress State ◽  
Production Stages ◽  
Axial Residual Stress ◽  
A New Technique

Cold coiling of high tensile steel rod into helical coil springs for the automotive industry is a new technique being implemented amongst spring manufacturers worldwide. To characterise this coil production process, the neutron strain scanning technique has been employed to non-destructively elucidate the influence production stages have on the tri-axial residual stress state. Samples investigated represented key production steps in the cold-coil forming process: Cold coiling; Tempering; Hot setting; Hot peening; Shot peening. Investigations revealed that the stress field was axi-symmetrical, that the dominant variation in all samples occurred along the hoop direction (helical circumference), whilst the radial and axial stresses are substantially lower. Accurate two-dimensional stress maps of the rod cross section have been compiled revealing key features associated with the cold coiling step. Comparison of the stress fields after each production step revealed altered stress values. The final shot peening process stage not only reduced stress concentrations at the internal bore, but contributed to the establishment of favourable surface residual stress conditions that enhance the fatigue life of the final product.

TEM investigations of surface residual stress relaxation in A12O3 and Al2O3-SiC nanocomposite

1994 ◽  
Vol 52 ◽  
pp. 628-629
Author(s):  
J. Fang ◽  
H. M. Chan ◽  
M. P. Harmer
Keyword(s):  
Residual Stress ◽  
Single Phase ◽  
Stress Relief ◽  
Stress Recovery ◽  
Surface Residual Stress ◽  
Microscopic Mechanism ◽  
Sic Particles ◽  
Annealing Procedure ◽  
The Difference ◽  
Nano Size

It was Niihara et al. who first discovered that the fracture strength of Al2O3 can be increased by incorporating as little as 5 vol.% of nano-size SiC particles (>1000 MPa), and that the strength would be improved further by a simple annealing procedure (>1500 MPa). This discovery has stimulated intense interest on Al2O3/SiC nanocomposites. Recent indentation studies by Fang et al. have shown that residual stress relief was more difficult in the nanocomposite than in pure Al2O3. In the present work, TEM was employed to investigate the microscopic mechanism(s) for the difference in the residual stress recovery in these two materials.Bulk samples of hot-pressed single phase Al2O3, and Al2O3 containing 5 vol.% 0.15 μm SiC particles were simultaneously polished with 15 μm diamond compound. Each sample was cut into two pieces, one of which was subsequently annealed at 1300° for 2 hours in flowing argon. Disks of 3 mm in diameter were cut from bulk samples.

scholarly journals Statistical analysis of the reproducibility of residual stress measurements in cold extruded parts

2021 ◽  
Author(s):  
Fabian Jaeger ◽  
Alessandro Franceschi ◽  
Holger Hoche ◽  
Peter Groche ◽  
Matthias Oechsner
Keyword(s):  
Residual Stress ◽  
Statistical Analysis ◽  
Stress Measurement ◽  
Industrial Applications ◽  
Cold Extrusion ◽  
X Ray Diffraction ◽  
Forming Process ◽  
X Ray ◽  
Stress States ◽  
Key Aspects

AbstractCold extruded components are characterized by residual stresses, which originate from the experienced manufacturing process. For industrial applications, reproducibility and homogeneity of the final components are key aspects for an optimized quality control. Although striving to obtain identical deformation and surface conditions, fluctuation in the manufacturing parameters and contact shear conditions during the forming process may lead to variations of the spatial residual stress distribution in the final product. This could lead to a dependency of the residual stress measurement results on the relative axial and circumferential position on the sample. An attempt to examine this problem is made by the employment of design of experiments (DoE) methods. A statistical analysis of the residual stress results generated through X-Ray diffraction is performed. Additionally, the ability of cold extrusion processes to generate uniform stress states is analyzed on specimens of austenitic stainless steel 1.4404 and possible correlations with the pre-deformed condition are statistically examined. Moreover, the influence of the coating, consisting of oxalate and a MoS2 based lubricant, on the X-Ray diffraction measurements of the surface is investigated.

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