Optimization of Local Laser Heat Treatment Process Using a Simple FE-Model

2013 ◽  
Vol 762 ◽  
pp. 360-367
Author(s):  
Antti Järvenpää ◽  
T. Kiuru ◽  
Antti Määttä ◽  
Matias Jaskari ◽  
Kari Mäntyjärvi
Keyword(s):  
Heat Treatment ◽  
Finite Element ◽  
Process Parameters ◽  
Treatment Process ◽  
Maximum Temperature ◽  
Fe Model ◽  
Heat Treatment Process ◽  
Laser Heat Treatment ◽  
Laser Heat ◽  
Heat Treated

Local laser heat treatment is an efficient method to manufacture tailored heat-treated steel strips. It can be applied to soften narrow zones of the strip in order to improve its formability on desired areas. However, the properties achieved are dependent on several process parameters. An objective is to develop a predictive model to optimize the heat treatment parameters instead of using experimental trials. In the present study, a finite element model was applied to predict the maximum temperature and heating and cooling rates, as well as the heat distribution along the heat treated area. To develop the model and to test its feasibility, experiments were performed, in which process parameters were varied to study their effects on temperature distribution in a 6 mm thick abrasion resistant steel grade. Scanning of a laser beam was used to optimize the width and depth of the heat-affected zone.In practice, local laser heat treatment process parameters have to be optimized with care for successful results. The most important task is to minimize the temperature gradient between the surfaces and to keep the peak temperatures close to the austenitizing temperature. The results indicate that a simple model can be used to predict the outcome of the heat treatment, so that finite element modeling can be adopted as a suitable tool for design of local heat treatments, allowing more advanced treatments and applications with complex geometries.

Application of Laser Heat Treatment Process on the Surface Treatment of Pipe Threaded

2012 ◽  
Vol 490-495 ◽  
pp. 3172-3176
Author(s):  
Jian Ying Liu ◽  
Jun Liu
Keyword(s):  
Heat Treatment ◽  
Treatment Process ◽  
Work Life ◽  
Oil Wells ◽  
Heat Treatment Process ◽  
Laser Heat Treatment ◽  
Process Technology ◽  
Remarkable Feature ◽  
Laser Heat ◽  
Laser Devices

The oil pipe is the special pipe of oil wells that is put into the wells to produce fluid or inject liquid. Because the pipe was put under the ground deeply, the higher strength and sealing are request. Therefore, the accuracy and strength of the connecting thread are required. Moreover, because of the oil wells need to be repaired frequently when they work, the shackle times are the important factor of the production life of the oil pipe. The development of the oil pipe is always blocked by the phenomenon of oil's gluing. As the remarkable feature of the Laser heat treatment process technology and the increasing of productions of the domestic laser devices, the laser heat treatment process technology was applied to the surface of the oil threaded to improve the integrated mechanical properties of oil pipe products and to extend its work life.

Optimization of the Case Depth of a Cylinder Made With 4340 Steel by a Control of the Laser Heat Treatment Parameters

2018 ◽  
Author(s):  
Rachid Fakir ◽  
Noureddine Barka ◽  
Jean Brousseau
Keyword(s):  
Heat Treatment ◽  
Numerical Model ◽  
Surface Temperature ◽  
Laser Power ◽  
Case Depth ◽  
Maximum Temperature ◽  
Laser Heat Treatment ◽  
Laser Heat ◽  
4340 Steel ◽  
Cylindrical Workpiece

This paper presents a numerical model able to control the temperature distribution along a 4340 steel cylinder heat-treated with Nd: YAG laser. The numerical model developed using the numerical finite element method, was based on a study of surface temperature variation and the adjustment of this temperature by a control of the heat treatment laser power. The proposed analytical approach was built gradually by (i) the development of a numerical model of laser heat treatment of the cylindrical workpiece, (ii) an analysis of the results of simulations and experimental tests, (iii) development of a laser power adjustment approach, and (iv) proposal of a laser power control predictor using neural networks. This approach was made possible by highlighting the influence of the fixed (non-variable) parameters of the laser heat treatment on the case depth, and has shown that it is possible by controlling the laser parameters to homogenize the distribution of the maximum temperature reached on the surface for a uniform case depth. The feasibility and effectiveness of the proposed approach leads to a reliable and accurate model able to guarantee a uniform surface temperature and a regular case depth for a cylindrical workpiece of a length of 50-mm and with a diameter of between 16-mm and 22-mm.

scholarly journals Effect of Laser Heat Treatment on the Microstructure and Properties of Alloy 800H

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 379 ◽  
Author(s):  
Wei Zhang ◽  
Tao Jiang ◽  
Jing Li ◽  
Liqiang Liu
Keyword(s):  
Heat Treatment ◽  
Treatment Process ◽  
Fracture Morphology ◽  
Elemental Content ◽  
Laser Heat Treatment ◽  
Alloy 800H ◽  
X Ray ◽  
Microstructure And Properties ◽  
Fracture Specimen ◽  
Laser Heat

The effects of laser heat treatment on the microstructure and properties of alloy 800H were investigated. The fracture morphology, elemental changes, and phase composition of the specimens were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffractometry (XRD). The results show that the long-lasting life of the specimen after laser heat treatment increased by 28.6%, and the elongation after fracture increased by 20.7%. The macroscopic morphology of the fracture specimen exhibited obvious ductile fracture morphology, and the changes in the elemental content and grain size significantly affected the ductility and toughness of the alloy. This study has certain guiding significance for the optimization of the heat treatment process of this type of alloy.

scholarly journals Improving the Inner Surface State of Thick-Walled Tubes by Heat Treatments with Internal Quenching Considering a Simulation Based Optimization

Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1303
Author(s):  
Fabian Mühl ◽  
Moritz Klug ◽  
Stefan Dietrich ◽  
Volker Schulze
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
Surface State ◽  
Treatment Process ◽  
Treatment Method ◽  
Fe Model ◽  
Heat Treatment Process ◽  
Residual Stress State ◽  
Optimization Study ◽  
Inner Surface

Internal Quenching is an innovative heat treatment method for difficult to access component sections. Especially, the microstructure, as well as the residual stress state at inner surfaces, of thick-walled tubes can be adjusted with the presented flexible heat treatment process. Based on multiphysical FE-models of two different steels, a simulative optimization study, considering different internal quenching strategies, was performed in order to find the optimal cooling conditions. The focus hereby was on the adjustment of a martensitic inner surface with high compressive residual stresses. The simulatively determined optimal cooling strategies were carried out experimentally and analyzed. A good agreement of the resulting hardness and residual stresses was achieved, validating the presented Fe-model of the Internal Quenching process. The shown results also indicate that the arising inner surface state is very sensitive to the transformation behavior of the used steel. Furthermore, the presented study shows that a preliminary simulative consideration of the heat treatment process helps to evaluate significant effects, reducing the experimental effort and time.

Formability of Ultrafine-Grained AA6016 Sheets Processed by Accumulative Roll Bonding

2012 ◽  
Vol 504-506 ◽  
pp. 575-580 ◽  
Author(s):  
Tina Hausöl ◽  
Christian W. Schmidt ◽  
Verena Maier ◽  
Wolfgang Böhm ◽  
Hung Nguyen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Laser Heat Treatment ◽  
Bending Tests ◽  
Roll Bonding ◽  
Laser Heat ◽  
Heat Treated ◽  
Ultrafine Grained ◽  
Ultrafine Grained Microstructure ◽  
Bending Behaviour

Aluminium alloy AA6016 was accumulative roll bonded up to eight cycles in order to produce an ultrafine-grained microstructure. The formability of these sheets was investigated by means of bending tests. Furthermore the influence of a local laser heat treatment at the bending edge is observed. The strength of the UFG samples is increased by a factor of around two compared to the conventionally grained T4 condition which also results in up to 50 % higher punch forces needed for bending of ARB processed samples. An anisotropic bending behaviour is observed. By applying a tailored laser heat treatment along the bending edge prior to the bending tests a local recrystallization and recovery at the deformation zone of the samples is achieved. Thus, ductility is increased locally whereby bending to an angle of 80° is possible with lower forming forces compared to the non-heat treated specimens. The results are compared to previous studies on mechanical properties and formability investigations of ARB processed AA6016.

Experimental Investigation of Residual Stresses after Heat Treatment and Grinding Processes in the Production of Ball Bearing Rings

2008 ◽  
Vol 571-572 ◽  
pp. 27-32 ◽  
Author(s):  
Volkan Güley ◽  
A. Erman Tekkaya ◽  
Turhan Savaş ◽  
Feridun Özhan
Keyword(s):  
Heat Treatment ◽  
Experimental Investigation ◽  
Residual Stresses ◽  
Process Parameters ◽  
Treatment Process ◽  
Ball Bearing ◽  
Grinding Process ◽  
Heat Treatment Process ◽  
Grinding Processes ◽  
Bearing Rings

Experimental investigation of residual stresses after heat treatment and grinding processes in the production of ball bearing rings has been carried out. The residual stresses were measured by X-ray diffraction method utilizing chromium radiation, which has an average penetration depth of 5 μm incident on 100Cr6 (AISI-E52100) ball bearing steel. The process parameters of heat treatment and grinding processes were varied so as to represent the extreme values that can be applied in the respective processes. Hardness and percent retained austenite limit the heat treatment process parameters; while roundness, surface roughness and form the grinding process. Tensile surface residual stresses on the raceway of ball bearing rings changes to compression after grinding in both circumferential and axial directions. In grinding relatively higher compressive stresses were measured in axial direction compared to the circumferential direction. This experimental investigation also showed that the influence of heat treatment process parameters on the magnitude and distribution of residual stresses survived even after grinding process; i.e. heat treatment and grinding processes cannot be evaluated independently in process design for favourable residual stresses.

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