Metallo-Thermo-Mechanical Simulation of Carburized Quenching Process by Several Codes - A Benchmark Project -

2007 ◽  
Vol 340-341 ◽  
pp. 1061-1066 ◽  
Author(s):  
Tatsuo Inoue ◽  
Youichi Watanabe ◽  
Kazuo Okamura ◽  
Michiharu Narazaki ◽  
Hayato Shichino ◽  
...  

As one of the activities carried out by our group of IMS-VHT (Virtual Heat Treatment tool for monitoring and optimising HT process), results of a benchmark project on the simulation of carburized quenching process is summarized. Several programs available for taking into account the metallo-thermo-mechanical coupling had been employed for the simulation for a cylinder, ring as well as a helical gear by use of common data of material properties and cooling characteristics. Comparison of the simulated values of distortion, residual stresses and profile of induced phases with the experimental data is made with some discussions.

Author(s):  
D G Walsh ◽  
A A Torrance ◽  
J Tiberg

Although thermally induced tensile residual stresses have been known to occur in ground components, it has not been possible to predict the critical temperature at which these stresses begin to manifest themselves in the workpiece. In this paper, a model of the formation of thermally induced tensile residual stresses is proposed and a simple method of calculating the critical temperature above which tensile residual stresses occur is developed. The analysis makes use of dimensional methods to characterize the critical temperature. In addition, a formula characterizing the yield strength as a function of temperature was developed. The model was then validated using finite element techniques and some experimental data. The analysis reveals that it is possible to determine the critical temperature above which tensile residual stresses will be manifested based on readily available material properties. A case study illustrates the application of the technique.


Author(s):  
Derek Shaffer ◽  
Sean Sehman ◽  
Ihab Ragai ◽  
John T. Roth ◽  
Bin Wang

Many manufacturers are looking towards electrical treatments as methods for reducing residual stresses in formed metals. Although many people have investigated the effects electricity has on residual stresses and plasticity, there has not been research investigating the effects it has as a post-treatment on strain hardening. Therefore, the goal of this research is to show the permanent changes in tensile properties that electrical treatments have on strain hardened metals, specifically Aluminum 2024. For this initial investigation, only one pulse duration and current density was used to categorize any changes in the metals due to applying electric current. This testing shows the difference between post-deformation heat treatments and post-deformation electrical treatments. Tensile properties of Aluminum 2024 were used to gauge the changes caused by the treatments. The heat treatment had the expected effect of lower the strength of the material and regrowing the grains while the electrical treatment did not seem to drastically change the structure of the grains, but still lowered the strength of the material. Microstructure investigations also showed that the material does in fact show slight changes in material properties, but no drastic changes in microstructure. These images also show that the regrowth from the heat treatment is clearly the reason for the decrease in strength.


2004 ◽  
Vol 120 ◽  
pp. 489-497
Author(s):  
R. Mukai ◽  
D.-Y. Ju

Predictions of deformation, residual stresses and hardness after heat treatment of gears by numerical simulation are very useful to determine optimum condition to decrease the distortion of machinery parts. In this paper, simulation on carburizing quenching of a helical gear made of carbon steel SCr420 was carried out using three-dimensional coupled analysis based on thermo-mechanical theory considering phase transformation. The expansion and latent heat due to phase transformation at various carburizing conditions were measured by TMA and DSC to determine the thermal physical properties of SCr420 carbon steel. The influence of the transformation plasticity strain on deformation, residual stress and hardness of a gear was clarified in the simulation. The accuracy of simulation also is verified by the comparison between the experimental data and the simulated result of the distortion and residual stress. From the predicted results, improvement of the hardness and strength on surface of the gear due to the carburizing-quenching process can be verified.


2013 ◽  
Vol 465-466 ◽  
pp. 647-651 ◽  
Author(s):  
Saifulnizan Jamian ◽  
Mohammad Rusydi Zainal Abidin

In this paper, mechanical properties of Al functionally graded materials (FGMs) crash box fabricated by heat treatment is predicted based on temperature distribution and experimental data. The Al FGM crash box is fabricated by applying different temperature at the both ends of a square hollow Al column for 4 hours. Due to the gradient in heat treatment temperature along the height of the Al column, the microstructure is locally varied so that a certain variation of local material properties is achieved. The determination of material properties at any point along the height of Al FGM crash box experimentally is uneasy. The Lagrange interpolation method is proposed to predict the variation of local material properties at any point along the height of Al FGM crash box for further work such as simulation of impact on the crash box. The determination of mechanical properties is successfully predicted using the available experimental data and the temperature distribution obtained in simulation.


Author(s):  
R. J. Dennis ◽  
S. Phillips ◽  
C. E. Truman ◽  
A. Stiles ◽  
R. Plant

The through life integrity of engineering components are routinely assessed using complex finite element methods. A critical input to such an assessment is an understanding of the operating environment, including service loading and temperature. Significant effort is expended identifying and understanding the effect of service loads on component integrity however there are many cases where service loading in isolation cannot account for premature failure of components during testing or in-service. A key assumption is that components in the as-built condition are often treated as stress and defect free and of nominal dimensions. This approach can however be inadequate and there are many documented cases where residual stress has influenced the in-service integrity of components. In this paper the magnitude and distribution of residual stresses are investigated in a quenched Aluminium 2014A TB test specimen. The test specimen has been specifically designed to contain design features representative of pressurised aerospace components which are quenched during manufacture. The specimen has two sections, one cylindrical (65mm internal diameter) and one oval (125mm largest internal diameter). The outer wall thickness is 10mm and the overall specimen length is 200mm with the two sections joined by a 30mm bridge section. The specimen has been subject to solution heat treatment at 505°C for five hours. Following heat treatment the specimen is rapidly quenched in cold water at 10°C with the cylindrical end entering the water first. Non-linear finite element methods have been developed to simulate the quenching process making use of user defined subroutines to enhance the standard features available in the finite element code. The accuracy of the predicted residual stresses has been assessed by comparison with neutron diffraction measurements at a range of critical locations. The work provides an extremely useful insight into how non-linear finite element methods can be successfully used to predict the residual stresses that are generated as a result of the quenching process. Where residual stresses are a potential integrity concern an understanding of the magnitude and spatial distribution of residual stress can be used to influence both the design and in-service operation of components.


2001 ◽  
Vol 123 (6) ◽  
pp. 528-535 ◽  
Author(s):  
Larry A. Taber ◽  
Jay D. Humphrey

A simple phenomenological model is used to study interrelations between material properties, growth-induced residual stresses, and opening angles in arteries. The artery is assumed to be a thick-walled tube composed of an orthotropic pseudoelastic material. In addition, the normal mature vessel is assumed to have uniform circumferential wall stress, which is achieved here via a mechanical growth law. Residual stresses are computed for three configurations: the unloaded intact artery, the artery after a single transmural cut, and the inner and outer rings of the artery created by combined radial and circumferential cuts. The results show that the magnitudes of the opening angles depend strongly on the heterogeneity of the material properties of the vessel wall and that multiple radial and circumferential cuts may be needed to relieve all residual stress. In addition, comparing computed opening angles with published experimental data for the bovine carotid artery suggests that the material properties change continuously across the vessel wall and that stress, not strain, correlates well with growth in arteries.


2004 ◽  
Vol 120 ◽  
pp. 481-488
Author(s):  
C. Franz ◽  
G. Besserdich ◽  
V. Schulze ◽  
H. Müller ◽  
D. Löhe

The simulation of manufacturing processes is more and more becoming an important tool in simultaneous engineering. The aim is to cut the time necessary for development and to optimise processes by simulation of the complete manufacturing chain. The field of heat treatment offers a large variety of applications for the use of simulation tools. Heat treatment of steels always includes the development of residual stresses and distortions. The geometry of the part, the composition of the material, the heat treatment process as well as the initial state of the part interact with each other in complex ways and have an influence on the distortion of the part. Using simulation the temporal development of temperature, phases, stresses and distortions while quenching as well as the residual stress distribution and distortion after quenching can be calculated. Transformation plasticity has been proved to be very important for heat treatment simulation. Three steels with identical contents of alloying elements but different carbon contents of 0.2, 0.5 and 0.8 wt.-% were analysed. The transformation plasticity constants for the martensitic transformation under tensile as well as compressive stresses were determined by quenching hollow specimen with nitrogen. Distortions and residual stresses were examined experimentally with cylinders made out of the three steels. Additionally, simulations of the quenching process of the cylinders were taken into account in the analysis of the experimental findings.


2017 ◽  
Vol 15 (3) ◽  
pp. 413 ◽  
Author(s):  
Miloš Milošević ◽  
Aleksandar Miltenović ◽  
Milan Banić ◽  
Miša Tomić

Residual stresses of the rail wheels are influenced by heat treatment during the manufacturing process. The quenching process during the manufacturing results in the residual stresses within the rail wheel that may be dangerous for the rail wheel during its operation. Determination of the residual stress in the rail wheel is important for understanding the damage mechanisms and their influence on the proper work of rail wheels. This paper presents a method for determining the residual stresses in the rail wheel during the quenching process by using the directly coupled thermal-structural analysis in ANSYS software.


Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1154
Author(s):  
Diego E. Lozano ◽  
George E. Totten ◽  
Yaneth Bedolla-Gil ◽  
Martha Guerrero-Mata ◽  
Marcel Carpio ◽  
...  

Automotive components manufacturers use the 5160 steel in leaf and coil springs. The industrial heat treatment process consists in austenitizing followed by the oil quenching and tempering process. Typically, compressive residual stresses are induced by shot peening on the surface of automotive springs to bestow compressive residual stresses that improve the fatigue resistance and increase the service life of the parts after heat treatment. In this work, a high-speed quenching was used to achieve compressive residual stresses on the surface of AISI/SAE 5160 steel samples by producing high thermal gradients and interrupting the cooling in order to generate a case-core microstructure. A special laboratory equipment was designed and built, which uses water as the quenching media in a high-speed water chamber. The severity of the cooling was characterized with embedded thermocouples to obtain the cooling curves at different depths from the surface. Samples were cooled for various times to produce different hardened case depths. The microstructure of specimens was observed with a scanning electron microscope (SEM). X-ray diffraction (XRD) was used to estimate the magnitude of residual stresses on the surface of the specimens. Compressive residual stresses at the surface and sub-surface of about −700 MPa were obtained.


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