The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Bin Han - One of the best experts on this subject based on the ideXlab platform.
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Numerical Simulation of the Effects of Scanning Velocity on the Process of Laser Transformation Hardening on the Inner Wall of Pump Barrel
Advanced Materials Research, 2012Co-Authors: Zhe Zhang, Bin Han, Yong Wang, Nan Nan WangAbstract:This study establishes a 3-D finite element model for the numerical simulation of laser transformation hardening on inner wall of pump barrel through a finite element code-SYSWELD. The change of thermal mechanical parameters with temperature is considered. The temperature field, metallurgy transformation and distribution of residual stress are predicted. The effect of scanning velocity on the temperature, martensite fraction and distribution of residual stress are studied. The results show that peak temperature in the Hardened Zone reaches to 1067.0°C and the maximum heating and cooling rate of Hardened Zone are 1.24×104°C/s and 3.68×103°C/s. After treatment, martensite can be obtained as a main phase in the Hardened Zone whose fraction increases with the decrease of scanning velocity. Compressive stress could be acquired in the Hardened Zone while the peak of tensile stress exists in the HAZ.
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Microstructure, hardness and stress in melted Zone of 42CrMo steel by wide-band laser surface melting
Optics and Lasers in Engineering, 2011Co-Authors: Yong Wang, Bin HanAbstract:Abstract Using laser surface melting (LSM) of a roller, to obtain the desired distribution of the microstructure, hardness and residual stresses with minimum distortion, is essential in order to improve machining efficiency and to achieve reliable service performance. In this study, a 3D finite element model has been developed to simulate the wide-band LSM process and predict the thermal and mechanical properties in the melted Zone. The microstructure evolution, hardness distribution and stress field in the melted Zone with different laser power were simulated. With the increase of the laser power from 3000 to 3800 W, the width and the depth of the laser melted layer increase, while the laser power has a little effect on the martensite contents, which exceed 90% in the melt-Hardened Zone. It greatly affects the mechanical properties in the melt-Hardened Zone with its volumetric expansion effect and the hardness increases by 2–3 times. The residual stress distributed within the melt-Hardened Zone is always of the compressive type. The amplitude of compressive stress exists in the transition region, and the amplitude of von Mises stress within the heat affected-Zone (HAZ) decreases with the increase in laser power. The accuracy of the developed finite element simulation strategy is validated for phase proportion and hardness distributions through the wide-band LSM on roller steel with proper instrumentation for data measurement. This agreement is encouraging.
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Computational and experimental study of a melt-Hardened Zone on a roller modified by wide-band laser treatment
Optics & Laser Technology, 2009Co-Authors: Huanxiao Zhan, Bin Han, Yong Wang, Tao Han, Weimin ZhaoAbstract:A three-dimensional finite element model has been developed to simulate the wide-band laser remelting process and predict the thermal and mechanical properties in the melt-Hardened Zone. The simulation of the laser remelting process was performed using the nonlinear thermo-mechanical properties, based on a wide-band heat source model. The temperature fields, phase transformations, hardness and residual stress distributions in the melt-Hardened Zone were analyzed. In the remelting Zone, the transformed volumetric percentage of martensite is beyond 80% and the excessive transformed martensitic structure greatly affects the mechanical properties in the melt-Hardened Zone with its volumetric expansion effect. After remelting, the hardness can be improved and the residual stress distributed within the melted Zone is mainly of the compressive type, while the tensile stress in the heat-affected Zone (HAZ) may cause the initiation of cracks. The computational results are in good agreement with experimental measurements.
Yong Wang - One of the best experts on this subject based on the ideXlab platform.
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Numerical Simulation of the Effects of Scanning Velocity on the Process of Laser Transformation Hardening on the Inner Wall of Pump Barrel
Advanced Materials Research, 2012Co-Authors: Zhe Zhang, Bin Han, Yong Wang, Nan Nan WangAbstract:This study establishes a 3-D finite element model for the numerical simulation of laser transformation hardening on inner wall of pump barrel through a finite element code-SYSWELD. The change of thermal mechanical parameters with temperature is considered. The temperature field, metallurgy transformation and distribution of residual stress are predicted. The effect of scanning velocity on the temperature, martensite fraction and distribution of residual stress are studied. The results show that peak temperature in the Hardened Zone reaches to 1067.0°C and the maximum heating and cooling rate of Hardened Zone are 1.24×104°C/s and 3.68×103°C/s. After treatment, martensite can be obtained as a main phase in the Hardened Zone whose fraction increases with the decrease of scanning velocity. Compressive stress could be acquired in the Hardened Zone while the peak of tensile stress exists in the HAZ.
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Microstructure, hardness and stress in melted Zone of 42CrMo steel by wide-band laser surface melting
Optics and Lasers in Engineering, 2011Co-Authors: Yong Wang, Bin HanAbstract:Abstract Using laser surface melting (LSM) of a roller, to obtain the desired distribution of the microstructure, hardness and residual stresses with minimum distortion, is essential in order to improve machining efficiency and to achieve reliable service performance. In this study, a 3D finite element model has been developed to simulate the wide-band LSM process and predict the thermal and mechanical properties in the melted Zone. The microstructure evolution, hardness distribution and stress field in the melted Zone with different laser power were simulated. With the increase of the laser power from 3000 to 3800 W, the width and the depth of the laser melted layer increase, while the laser power has a little effect on the martensite contents, which exceed 90% in the melt-Hardened Zone. It greatly affects the mechanical properties in the melt-Hardened Zone with its volumetric expansion effect and the hardness increases by 2–3 times. The residual stress distributed within the melt-Hardened Zone is always of the compressive type. The amplitude of compressive stress exists in the transition region, and the amplitude of von Mises stress within the heat affected-Zone (HAZ) decreases with the increase in laser power. The accuracy of the developed finite element simulation strategy is validated for phase proportion and hardness distributions through the wide-band LSM on roller steel with proper instrumentation for data measurement. This agreement is encouraging.
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Computational and experimental study of a melt-Hardened Zone on a roller modified by wide-band laser treatment
Optics & Laser Technology, 2009Co-Authors: Huanxiao Zhan, Bin Han, Yong Wang, Tao Han, Weimin ZhaoAbstract:A three-dimensional finite element model has been developed to simulate the wide-band laser remelting process and predict the thermal and mechanical properties in the melt-Hardened Zone. The simulation of the laser remelting process was performed using the nonlinear thermo-mechanical properties, based on a wide-band heat source model. The temperature fields, phase transformations, hardness and residual stress distributions in the melt-Hardened Zone were analyzed. In the remelting Zone, the transformed volumetric percentage of martensite is beyond 80% and the excessive transformed martensitic structure greatly affects the mechanical properties in the melt-Hardened Zone with its volumetric expansion effect. After remelting, the hardness can be improved and the residual stress distributed within the melted Zone is mainly of the compressive type, while the tensile stress in the heat-affected Zone (HAZ) may cause the initiation of cracks. The computational results are in good agreement with experimental measurements.
Radovan Kovacevic - One of the best experts on this subject based on the ideXlab platform.
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study on the strength and failure modes of laser welded galvanized dp980 steel lap joints
Journal of Materials Processing Technology, 2014Co-Authors: Fanrong Kong, Wei Liu, Blair E Carlson, Radovan KovacevicAbstract:Abstract The mechanical properties of different sections of the laser welded galvanized high strength dual phase (DP) 980 steel lap joint such as the Hardened Zone (fusion Zone and the grain coarsened heat affected Zone (HAZ)), the softened Zone (subcritical HAZ), and the base material were determined through mini-tensile tests. The numerically-predicted load–displacement curve and the sample rotation angle were verified by experimental measurements. The FE model considering the non-homogeneous mechanical properties was built based on the weld cross section geometries that were obtained under various laser welding conditions. The numerically-predicted von Mises equivalent strain concentrations and failure modes of the galvanized DP980 lap joints with respect to different laser welding conditions exhibit reasonable agreement with the experimental results.
S. Torng - One of the best experts on this subject based on the ideXlab platform.
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Improved impact toughness of 13Cr martensitic stainless steel Hardened by laser
Journal of Materials Engineering and Performance, 2002Co-Authors: L. W. Tsay, Y. M. Chang, S. TorngAbstract:The impact toughness of AISI 403 martensitic stainless steel plate and laser-Hardened specimens tempered at various temperatures were examined. Phosphorus was the primary residual impurity responsible for tempered embrittlement of this alloy. The experimental result also indicated that AISI 403 stainless steel was very sensitive to reverse-temper embrittlement. The improved impact toughness of the laser-Hardened specimen was attributed to the refined microstructure in the laser-Hardened Zone.
Fanrong Kong - One of the best experts on this subject based on the ideXlab platform.
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study on the strength and failure modes of laser welded galvanized dp980 steel lap joints
Journal of Materials Processing Technology, 2014Co-Authors: Fanrong Kong, Wei Liu, Blair E Carlson, Radovan KovacevicAbstract:Abstract The mechanical properties of different sections of the laser welded galvanized high strength dual phase (DP) 980 steel lap joint such as the Hardened Zone (fusion Zone and the grain coarsened heat affected Zone (HAZ)), the softened Zone (subcritical HAZ), and the base material were determined through mini-tensile tests. The numerically-predicted load–displacement curve and the sample rotation angle were verified by experimental measurements. The FE model considering the non-homogeneous mechanical properties was built based on the weld cross section geometries that were obtained under various laser welding conditions. The numerically-predicted von Mises equivalent strain concentrations and failure modes of the galvanized DP980 lap joints with respect to different laser welding conditions exhibit reasonable agreement with the experimental results.
