To meet the demands of continuous stream-line for component production in the thixo-forming industry, billet heating should be of high quality and in a controllable way. A 4-step inductive heating strategy for aluminu...To meet the demands of continuous stream-line for component production in the thixo-forming industry, billet heating should be of high quality and in a controllable way. A 4-step inductive heating strategy for aluminum alloy A356 was performed. Thixotropic testing and microstructure analysis showed that a homogenous temperature distribution was achieved after temperature-power-time optimization. Theoretical analysis was given concerning the thermal conductivity and heat capacity of A356 between conventional and semisolid casting microstructures. The experimental results show that the optimized 4-step strategy could be the best strategy for billet heating during the thixo-forming of aluminum alloy A356.展开更多
Undoped nickel-based catalysts supported on depleted uranium oxide allow one to carry out CO_(2)methanation process under extremely low reaction temperature under atmospheric pressure and powered by a contactless indu...Undoped nickel-based catalysts supported on depleted uranium oxide allow one to carry out CO_(2)methanation process under extremely low reaction temperature under atmospheric pressure and powered by a contactless induction heating.By adjusting the reaction conditions,the catalyst is able to perform CO_(2)methanation reaction under autothermal process operated inside a non-adiabatic reactor,without any external energy supply.Such autothermal process is possible thanks to the high apparent density of the UO_x which allows one to confine the reaction heat in a small catalyst volume in order to confine the exothermicity of the reaction inside the catalyst and to operate the reaction at equilibrium heat in-heat out.Such autothermal operation mode allows one to significantly reduce the complexity of the process compared to that operated using adiabatic reactor,where complete insulation is required to prevent heat disequilibrium,in order to reduce as much as possible,the heat exchange with the external medium.The catalyst displays an extremely high stability as a function of time on stream as no apparent deactivation.It is expected that such new catalyst with unprecedented catalytic performance could open new era in the field of heterogeneous catalysis where traditional supports show their limitations to operate catalytic processes under severe reaction conditions.展开更多
We examine a convective dissipation-free heat transfer in melts under the action of a stationary component of electromagnetic body force induced by frequency-modulated travelling magnetic field.The influence of MHD pa...We examine a convective dissipation-free heat transfer in melts under the action of a stationary component of electromagnetic body force induced by frequency-modulated travelling magnetic field.The influence of MHD parameters of turbulent flow on the transfer process is studied.展开更多
The purpose of this paper is to investigate the feasibility of high-frequency induction heat for the line heating process through a series of experimental studies and numerical calculations. The results show that the ...The purpose of this paper is to investigate the feasibility of high-frequency induction heat for the line heating process through a series of experimental studies and numerical calculations. The results show that the heating temperature of induction heating meets the demands of steel plate bending, and the deformation of a steel plate heated by induction heating can achieve the same effect as flame heating. Meanwhile, the finite element model of moving induction heating of the plate is developed, and the comparison of the residual strain fields and transverse shrinkage between these two kinds of heating shows that great similarity has been achieved.展开更多
An experimental and numerical study on the temperature field induced in the ultra-high frequency induction heating is carried out.With an aim of predicting the thermal history of the workpiece,the influence factors of...An experimental and numerical study on the temperature field induced in the ultra-high frequency induction heating is carried out.With an aim of predicting the thermal history of the workpiece,the influence factors of temperature field,such as the induction frequency,the dimension of coil and the gap between coil and workpiece,are investigated considering temperature-dependent material properties by using FLUX 2Dsoftware.The temperature field characteristic in ultra-high induction heating is obtained and discussed.The numerical values are compared with the experimental results.A good agreement between them is observed with 7.9% errors.展开更多
Under various electromagnetic induction heating powers,different Al3Ti/Al composites were fabricated by in-situ synthesis method from aluminum and titanium fibers.Microstructures and particles distribution of the comp...Under various electromagnetic induction heating powers,different Al3Ti/Al composites were fabricated by in-situ synthesis method from aluminum and titanium fibers.Microstructures and particles distribution of the composites were examined by XRD,SEM and EDS.The results show that no other intermetallic compounds beside Al3Ti can be in-situ synthesized.Around the titanium fibers,the reaction zones and diffusion zones can be obviously found.Due to the stirring of the electromagnetic function,the formation of the micro-cracks inside the reaction zone was conducive to the peeling off of the Al3Ti particles,and ensures the continuous reaction between liquid aluminum and titanium fibers,as well as the diffusion of Al3Ti particles.At the same time,there were secondary splits of Al3Ti particles located in diffusion zones.Two-body abrasion test shows that with the increase of induction heating power,the wear rates of the composites reduced and the number of grooves decreased.展开更多
This paper presents a novel mega-Hz-level super high frequency zero-voltage soft-switching converter for induction heating power supplies. The prominent advantage of this topology is that it can absorb both inductive ...This paper presents a novel mega-Hz-level super high frequency zero-voltage soft-switching converter for induction heating power supplies. The prominent advantage of this topology is that it can absorb both inductive and capacitive parasitic components in the converter. The switch devices operate in a zero-voltage soft-switching mode. Consequently, the high voltage and high current spikes caused by parasitic inductors or capacitors oscillation do not occur in this circuit, and the high power loss caused by high frequency switching can be greatly reduced. A large value inductor is adopted between the input capacitor and the switches, thus, this novel converter shares the benefits of both voltage-type and current-type circuits simultaneously, and there are no needs of dead time between two switches. The working principles in different modes are introduced. Results of simulation and experiments operated at around 1 MHz frequency verify the validity of parasitic components absorption and show that this convener is competent for super high frequency applications.展开更多
In the production of hot extrusion pipes, the billet will be heated in an induction furnace, before piercing or extrusion,to a certain temperature. The induction heating temperature field profile in the billet will ex...In the production of hot extrusion pipes, the billet will be heated in an induction furnace, before piercing or extrusion,to a certain temperature. The induction heating temperature field profile in the billet will exert an influence on the deformation processes. The study has developed an data conversion program to convert the temperature data from induction heating by ANSYS to deformation simulation software DEFORM; therefore, not only the relatively accurate temperature field can be made available, compared with the usually assumed uniform temperature field, but also the connection between induction heating and deformation can be established, which is essential to evaluate the processing parameters. Numerical simulation of the piercing processes of different temperature fields by induction heating was carded out, and the results have shown that the different initial temperature fields in the billet can lead to different deformation curves, which indicates that the conversion program is necessary to study the production process of hot extrusion pipes.展开更多
A magnetic and temperature field-coupled mathematical model is proposed to calculate the induction heating process of a discard substitution block for billet hot extrusion process. The mathematical model is validated ...A magnetic and temperature field-coupled mathematical model is proposed to calculate the induction heating process of a discard substitution block for billet hot extrusion process. The mathematical model is validated by comparing simulation results with temperature measurements recorded during physical modeling. Based on systematical analysis of calculation results, a quantitative sawtooth induction power curve was proposed to realize the aim of achieving the best distributed temperature field in the block within the shortest induction time.展开更多
Owing to the development of new products and higher requirement of product properties, the current existing induction heating technology of Baosteel can no longer satisfy the new requirements of the product line. Cont...Owing to the development of new products and higher requirement of product properties, the current existing induction heating technology of Baosteel can no longer satisfy the new requirements of the product line. Control of the induction heating temperature to an appropriate value is a key consideration in induction heating technology. To obtain acculturated temperatures, investigations were focused on the parameters of an induction heating system, including those of induction heating equipment and heating processes. In these investigations, computer simulation was used to model the induction heating process, followed by physical experimentation to verify and improve the simulation model; finally, optimized induction heating parameters were suggested. The use of computer simulations dramatically decreased physical experimental times, and the computed heating parameters were used to guide the physical experimentation and design of the product line ; this increased the efficiency of subsequent investigations. This study focuses on the development of induction heating technology in Baosteel, which includes the overall induction heating technology used in manufacturing backup rollers and in the thermomechanical control process.展开更多
The shear failure modes and respective failure mechanism of Sn3.5Ag and Sn3.0Ag0.5Cu lead-free solder bumping on Au/Ni/Cu metallization formed by induction spontaneous heating reflow process have been investigated thr...The shear failure modes and respective failure mechanism of Sn3.5Ag and Sn3.0Ag0.5Cu lead-free solder bumping on Au/Ni/Cu metallization formed by induction spontaneous heating reflow process have been investigated through the shear test after aging at 120℃ for 0, 1, 4, 9 and 16 d. Different typical shear failure behaviors have been found in the loading curves （shear force vs displacement）. From the results of interracial morphology analysis of the fracture surfaces and cross-sections, two main typical failure modes have been identified. The probabilities of the failure modes occurrence are inconsistent when the joints were aged for different times. The evolution of the brittle NiaSn4 and Cu-Ni-Au-Sn layers and the grains coarsening of the solder bulk are the basic reasons for the change of shear failure modes.展开更多
The temperature distribution of steel plates is affected by heating rates and heating curves in the process of induction heating.The magnetic flux density inside the induction furnace was measured,the distribution of ...The temperature distribution of steel plates is affected by heating rates and heating curves in the process of induction heating.The magnetic flux density inside the induction furnace was measured,the distribution of magnetic flux density was analyzed and the uniform area of the induction heating temperature distribution was ascertained.The locations for measuring temperature were set and the temperature in different processes was measured.The influence of heating rates and heating curves on the temperature difference of steel plates was studied.The experimental results showed that the steel plates’ temperature difference increased with the increase of the heating rate.The temperature difference was obviously affected by different heating curves when the heating rate was the same.A suitable heating curve would be beneficial to reduction of steel plates’ temperature difference.展开更多
Expansion is an important operation in the hot extrusion production line of seamless steel tubes, which is to produce proper hollow billets for extrusion. The billet goes through induction heating before expanded to a...Expansion is an important operation in the hot extrusion production line of seamless steel tubes, which is to produce proper hollow billets for extrusion. The billet goes through induction heating before expanded to acquire a proper temperature. In this study, the effects of three types of inhomogeneous temperature fields on 321 stainless tubes during the expansion process were simulated. The results have indicated that it was an optimum temperature filed for expansion, where the temperature varied linearly along radial direction and the temperature was lower on the inner surface. This temperature field is beneficial to improving the stability of expansion and ensuring dimensional accuracy and increasing the utilization rate of tubular billet material.展开更多
The electromagnetic and temperature fields in the multistage intermediate-frequency induction heating of coated steel tubes were calculated using a numerical simulation.The influence of the voltage and frequency on th...The electromagnetic and temperature fields in the multistage intermediate-frequency induction heating of coated steel tubes were calculated using a numerical simulation.The influence of the voltage and frequency on the parameters of power circuit and heating temperature of the steel pipe was also analyzed.The results indicate that:(1) the electromagnetic field of induction heating is concentrated between the induction coil and steel tube and dissipated more at both ends of the coil;(2) during the induction heating,the temperature difference between the outer and inner walls of the steel pipe is approximately 3040 K,and the two temperatures rapidly tend to be the same after exiting the induction heater;(3)during the natural cooling,the temperature drop of the steel tube in the low-temperature section is approximately 10 K,and that in the high-temperature section is approximately 20 K;(4)the appropriate induction heating frequency and matching capacitance should be selected,so that the temperature of the steel pipe,especially at the outer wall,meets the coating process requirements,and as to achieve a synchronous improvement of the power efficiency and heating efficiency.This study is beneficial to building a more low-consumption and high-efficiency coating line of large-diameter steel pipes in Baosteel.展开更多
To address the phenomenon of sparking during the edge induction heating process in hot strip mills,this paper uses numerical simulation to systematically investigate the key factors influencing sparking and their effe...To address the phenomenon of sparking during the edge induction heating process in hot strip mills,this paper uses numerical simulation to systematically investigate the key factors influencing sparking and their effects.The distribution of induced current density in the steel plate above roller conveyor table during the heating process is calculated and compared under different conditions,including the relative positions of the steel plate and induction coil,the width of the steel plate,and changes in load. The results show that when a narrow steel plate is heated or the steel plate shifts to the side of the induction coil,sparking between the steel plate and roller conveyor is more likely to occur.展开更多
In this study,a C-Mn quenched steel tube was quickly tempered by induction heating,and the influence of the tempering temperature on its performance was studied and compared with that by traditional tempering. The res...In this study,a C-Mn quenched steel tube was quickly tempered by induction heating,and the influence of the tempering temperature on its performance was studied and compared with that by traditional tempering. The results show that the yield strength of both is quite strong with regular changes in the tempering temperature,but that the tensile strength of the tube tempered by induction heating is higher than that tempered by traditional tempering by about 25 MPa,and the elongation after induction tempering is significantly higher than that after traditional tempering. The differences in the microstructures of tubes after induction and traditional tempering were compared by metallographic microscope,scanning electron microscopy,and transmission electron microscopy.Theoretical analysis was also performed. Compared with traditional tempering,a fine dispersion of precipitated carbides occurs after induction tempering,which is the main reason for the performance differences.展开更多
In order to speed up the production and save more energy in hot stamping process,the induction heating technology as a new effective heating method is considerable.Finite element(FE)-simulation and a series of experim...In order to speed up the production and save more energy in hot stamping process,the induction heating technology as a new effective heating method is considerable.Finite element(FE)-simulation and a series of experiments are carried out to research the temperature homogenization of induction heating with the face inductor.It is found the edge effect has a notable influence on the temperature distribution.Results concerning the mechanical properties of the stamped part as well as surface characteristics will be presented and discussed.展开更多
A three-dimensional electromagnetic thermal coupled model of a 45#steel strip during longitudinal magnetic flux induction heating was established in this study.The influence of different power levels,frequencies,and e...A three-dimensional electromagnetic thermal coupled model of a 45#steel strip during longitudinal magnetic flux induction heating was established in this study.The influence of different power levels,frequencies,and electromagnetic shielding on the magnetic induction intensity and the heating of parts of different materials around the inductor was analyzed by calculating the magnetic induction intensity around the longitudinal flux induction heater under different conditions.The results show that leakage flux can be reduced up to 49%by electromagnetic shielding.The higher the frequency,the greater the electromagnetic shielding effect,and the lower the magnetic leakage around the inductor.Conversely,the higher the power,the greater the magnetic induction around the inductor.By adding electromagnetic shielding to reduce magnetic leakage of the inductor and replacing the metal part material around the inductor with stainless steel,the heat generation of the parts around the inductor can be greatly reduced.展开更多
The complex interaction between material properties in an induction heating circuit was studied by multi physics simulation and by experimental verification in a full-scale laboratory heater. The work aims to illustra...The complex interaction between material properties in an induction heating circuit was studied by multi physics simulation and by experimental verification in a full-scale laboratory heater. The work aims to illustrate the complexity of the system of interacting materials, but also to propose a method to verify properties of soft magnetic composite materials in an integrated system and to identify which properties are the most critical under different circumstances and load cases. Heat losses at different loads were primarily studied, from DC currents to AC currents at 15, 20 and 25 kHz, respectively. A FE model for magnetic simulation was correlated with a corresponding model for heat simulation. The numerical model, as well as the established input material data, could be verified through the experimental measurements. In this particular study, the current loss in the litz wire was the dominant heat source, thus making the thermal conductivity of the SMC the most important property in this material.展开更多
Improving the efficiency of induction heating of parts in the air gap of the magnetic circuit is associated with the use of surface and edge effects.Through modeling in ANSYS Electromagnetics Suite 19.2 and experiment...Improving the efficiency of induction heating of parts in the air gap of the magnetic circuit is associated with the use of surface and edge effects.Through modeling in ANSYS Electromagnetics Suite 19.2 and experimental studies identified patterns of edge effect in the heated parts.To ensure the uniformity of induction heating of small parts and reduce the soldering time,the electrical switch of soldered parts is used,which with the help of device controller forms a secondary circuit with low electrical resistance and high density of eddy currents.展开更多
基金supported by the National High-Tech Research and Development Program of China (No.2007AA03Z119)the Innovation Programs of China Electronics Technology Group Corporation (No.81AA10042)
文摘To meet the demands of continuous stream-line for component production in the thixo-forming industry, billet heating should be of high quality and in a controllable way. A 4-step inductive heating strategy for aluminum alloy A356 was performed. Thixotropic testing and microstructure analysis showed that a homogenous temperature distribution was achieved after temperature-power-time optimization. Theoretical analysis was given concerning the thermal conductivity and heat capacity of A356 between conventional and semisolid casting microstructures. The experimental results show that the optimized 4-step strategy could be the best strategy for billet heating during the thixo-forming of aluminum alloy A356.
基金ORANO Chimie-Enrichissement Co.for the financial support of this project。
文摘Undoped nickel-based catalysts supported on depleted uranium oxide allow one to carry out CO_(2)methanation process under extremely low reaction temperature under atmospheric pressure and powered by a contactless induction heating.By adjusting the reaction conditions,the catalyst is able to perform CO_(2)methanation reaction under autothermal process operated inside a non-adiabatic reactor,without any external energy supply.Such autothermal process is possible thanks to the high apparent density of the UO_x which allows one to confine the reaction heat in a small catalyst volume in order to confine the exothermicity of the reaction inside the catalyst and to operate the reaction at equilibrium heat in-heat out.Such autothermal operation mode allows one to significantly reduce the complexity of the process compared to that operated using adiabatic reactor,where complete insulation is required to prevent heat disequilibrium,in order to reduce as much as possible,the heat exchange with the external medium.The catalyst displays an extremely high stability as a function of time on stream as no apparent deactivation.It is expected that such new catalyst with unprecedented catalytic performance could open new era in the field of heterogeneous catalysis where traditional supports show their limitations to operate catalytic processes under severe reaction conditions.
文摘We examine a convective dissipation-free heat transfer in melts under the action of a stationary component of electromagnetic body force induced by frequency-modulated travelling magnetic field.The influence of MHD parameters of turbulent flow on the transfer process is studied.
基金Supported by the National Natural Science Foundation of China (50805016)
文摘The purpose of this paper is to investigate the feasibility of high-frequency induction heat for the line heating process through a series of experimental studies and numerical calculations. The results show that the heating temperature of induction heating meets the demands of steel plate bending, and the deformation of a steel plate heated by induction heating can achieve the same effect as flame heating. Meanwhile, the finite element model of moving induction heating of the plate is developed, and the comparison of the residual strain fields and transverse shrinkage between these two kinds of heating shows that great similarity has been achieved.
基金Supported by the National Science and Technology Major Project of China(2012ZX04003081)
文摘An experimental and numerical study on the temperature field induced in the ultra-high frequency induction heating is carried out.With an aim of predicting the thermal history of the workpiece,the influence factors of temperature field,such as the induction frequency,the dimension of coil and the gap between coil and workpiece,are investigated considering temperature-dependent material properties by using FLUX 2Dsoftware.The temperature field characteristic in ultra-high induction heating is obtained and discussed.The numerical values are compared with the experimental results.A good agreement between them is observed with 7.9% errors.
基金Project(2015DFR50990-01)supported by International Cooperation Project of Ministry of Science and Technology of ChinaProjects(18JS060,18JS075)supported by the Shaanxi Key Laboratory of Nano-materials and Technology,China。
文摘Under various electromagnetic induction heating powers,different Al3Ti/Al composites were fabricated by in-situ synthesis method from aluminum and titanium fibers.Microstructures and particles distribution of the composites were examined by XRD,SEM and EDS.The results show that no other intermetallic compounds beside Al3Ti can be in-situ synthesized.Around the titanium fibers,the reaction zones and diffusion zones can be obviously found.Due to the stirring of the electromagnetic function,the formation of the micro-cracks inside the reaction zone was conducive to the peeling off of the Al3Ti particles,and ensures the continuous reaction between liquid aluminum and titanium fibers,as well as the diffusion of Al3Ti particles.At the same time,there were secondary splits of Al3Ti particles located in diffusion zones.Two-body abrasion test shows that with the increase of induction heating power,the wear rates of the composites reduced and the number of grooves decreased.
文摘This paper presents a novel mega-Hz-level super high frequency zero-voltage soft-switching converter for induction heating power supplies. The prominent advantage of this topology is that it can absorb both inductive and capacitive parasitic components in the converter. The switch devices operate in a zero-voltage soft-switching mode. Consequently, the high voltage and high current spikes caused by parasitic inductors or capacitors oscillation do not occur in this circuit, and the high power loss caused by high frequency switching can be greatly reduced. A large value inductor is adopted between the input capacitor and the switches, thus, this novel converter shares the benefits of both voltage-type and current-type circuits simultaneously, and there are no needs of dead time between two switches. The working principles in different modes are introduced. Results of simulation and experiments operated at around 1 MHz frequency verify the validity of parasitic components absorption and show that this convener is competent for super high frequency applications.
文摘In the production of hot extrusion pipes, the billet will be heated in an induction furnace, before piercing or extrusion,to a certain temperature. The induction heating temperature field profile in the billet will exert an influence on the deformation processes. The study has developed an data conversion program to convert the temperature data from induction heating by ANSYS to deformation simulation software DEFORM; therefore, not only the relatively accurate temperature field can be made available, compared with the usually assumed uniform temperature field, but also the connection between induction heating and deformation can be established, which is essential to evaluate the processing parameters. Numerical simulation of the piercing processes of different temperature fields by induction heating was carded out, and the results have shown that the different initial temperature fields in the billet can lead to different deformation curves, which indicates that the conversion program is necessary to study the production process of hot extrusion pipes.
基金financially supported by National Science Foundation of China ( NO. 51274137 and NO. 11372174)
文摘A magnetic and temperature field-coupled mathematical model is proposed to calculate the induction heating process of a discard substitution block for billet hot extrusion process. The mathematical model is validated by comparing simulation results with temperature measurements recorded during physical modeling. Based on systematical analysis of calculation results, a quantitative sawtooth induction power curve was proposed to realize the aim of achieving the best distributed temperature field in the block within the shortest induction time.
文摘Owing to the development of new products and higher requirement of product properties, the current existing induction heating technology of Baosteel can no longer satisfy the new requirements of the product line. Control of the induction heating temperature to an appropriate value is a key consideration in induction heating technology. To obtain acculturated temperatures, investigations were focused on the parameters of an induction heating system, including those of induction heating equipment and heating processes. In these investigations, computer simulation was used to model the induction heating process, followed by physical experimentation to verify and improve the simulation model; finally, optimized induction heating parameters were suggested. The use of computer simulations dramatically decreased physical experimental times, and the computed heating parameters were used to guide the physical experimentation and design of the product line ; this increased the efficiency of subsequent investigations. This study focuses on the development of induction heating technology in Baosteel, which includes the overall induction heating technology used in manufacturing backup rollers and in the thermomechanical control process.
文摘The shear failure modes and respective failure mechanism of Sn3.5Ag and Sn3.0Ag0.5Cu lead-free solder bumping on Au/Ni/Cu metallization formed by induction spontaneous heating reflow process have been investigated through the shear test after aging at 120℃ for 0, 1, 4, 9 and 16 d. Different typical shear failure behaviors have been found in the loading curves （shear force vs displacement）. From the results of interracial morphology analysis of the fracture surfaces and cross-sections, two main typical failure modes have been identified. The probabilities of the failure modes occurrence are inconsistent when the joints were aged for different times. The evolution of the brittle NiaSn4 and Cu-Ni-Au-Sn layers and the grains coarsening of the solder bulk are the basic reasons for the change of shear failure modes.
文摘The temperature distribution of steel plates is affected by heating rates and heating curves in the process of induction heating.The magnetic flux density inside the induction furnace was measured,the distribution of magnetic flux density was analyzed and the uniform area of the induction heating temperature distribution was ascertained.The locations for measuring temperature were set and the temperature in different processes was measured.The influence of heating rates and heating curves on the temperature difference of steel plates was studied.The experimental results showed that the steel plates’ temperature difference increased with the increase of the heating rate.The temperature difference was obviously affected by different heating curves when the heating rate was the same.A suitable heating curve would be beneficial to reduction of steel plates’ temperature difference.
文摘Expansion is an important operation in the hot extrusion production line of seamless steel tubes, which is to produce proper hollow billets for extrusion. The billet goes through induction heating before expanded to acquire a proper temperature. In this study, the effects of three types of inhomogeneous temperature fields on 321 stainless tubes during the expansion process were simulated. The results have indicated that it was an optimum temperature filed for expansion, where the temperature varied linearly along radial direction and the temperature was lower on the inner surface. This temperature field is beneficial to improving the stability of expansion and ensuring dimensional accuracy and increasing the utilization rate of tubular billet material.
文摘The electromagnetic and temperature fields in the multistage intermediate-frequency induction heating of coated steel tubes were calculated using a numerical simulation.The influence of the voltage and frequency on the parameters of power circuit and heating temperature of the steel pipe was also analyzed.The results indicate that:(1) the electromagnetic field of induction heating is concentrated between the induction coil and steel tube and dissipated more at both ends of the coil;(2) during the induction heating,the temperature difference between the outer and inner walls of the steel pipe is approximately 3040 K,and the two temperatures rapidly tend to be the same after exiting the induction heater;(3)during the natural cooling,the temperature drop of the steel tube in the low-temperature section is approximately 10 K,and that in the high-temperature section is approximately 20 K;(4)the appropriate induction heating frequency and matching capacitance should be selected,so that the temperature of the steel pipe,especially at the outer wall,meets the coating process requirements,and as to achieve a synchronous improvement of the power efficiency and heating efficiency.This study is beneficial to building a more low-consumption and high-efficiency coating line of large-diameter steel pipes in Baosteel.
文摘To address the phenomenon of sparking during the edge induction heating process in hot strip mills,this paper uses numerical simulation to systematically investigate the key factors influencing sparking and their effects.The distribution of induced current density in the steel plate above roller conveyor table during the heating process is calculated and compared under different conditions,including the relative positions of the steel plate and induction coil,the width of the steel plate,and changes in load. The results show that when a narrow steel plate is heated or the steel plate shifts to the side of the induction coil,sparking between the steel plate and roller conveyor is more likely to occur.
文摘In this study,a C-Mn quenched steel tube was quickly tempered by induction heating,and the influence of the tempering temperature on its performance was studied and compared with that by traditional tempering. The results show that the yield strength of both is quite strong with regular changes in the tempering temperature,but that the tensile strength of the tube tempered by induction heating is higher than that tempered by traditional tempering by about 25 MPa,and the elongation after induction tempering is significantly higher than that after traditional tempering. The differences in the microstructures of tubes after induction and traditional tempering were compared by metallographic microscope,scanning electron microscopy,and transmission electron microscopy.Theoretical analysis was also performed. Compared with traditional tempering,a fine dispersion of precipitated carbides occurs after induction tempering,which is the main reason for the performance differences.
基金National Natural Science Foundation of China （No. 51275185, No. 51405171） Graduate Innovation and Entrepreneurship Fund of Huazhong University of Science and Technology （No. 0109070112） Fundamental Research Funds for the Central Universities （No. 0118110621）
文摘In order to speed up the production and save more energy in hot stamping process,the induction heating technology as a new effective heating method is considerable.Finite element(FE)-simulation and a series of experiments are carried out to research the temperature homogenization of induction heating with the face inductor.It is found the edge effect has a notable influence on the temperature distribution.Results concerning the mechanical properties of the stamped part as well as surface characteristics will be presented and discussed.
文摘A three-dimensional electromagnetic thermal coupled model of a 45#steel strip during longitudinal magnetic flux induction heating was established in this study.The influence of different power levels,frequencies,and electromagnetic shielding on the magnetic induction intensity and the heating of parts of different materials around the inductor was analyzed by calculating the magnetic induction intensity around the longitudinal flux induction heater under different conditions.The results show that leakage flux can be reduced up to 49%by electromagnetic shielding.The higher the frequency,the greater the electromagnetic shielding effect,and the lower the magnetic leakage around the inductor.Conversely,the higher the power,the greater the magnetic induction around the inductor.By adding electromagnetic shielding to reduce magnetic leakage of the inductor and replacing the metal part material around the inductor with stainless steel,the heat generation of the parts around the inductor can be greatly reduced.
文摘The complex interaction between material properties in an induction heating circuit was studied by multi physics simulation and by experimental verification in a full-scale laboratory heater. The work aims to illustrate the complexity of the system of interacting materials, but also to propose a method to verify properties of soft magnetic composite materials in an integrated system and to identify which properties are the most critical under different circumstances and load cases. Heat losses at different loads were primarily studied, from DC currents to AC currents at 15, 20 and 25 kHz, respectively. A FE model for magnetic simulation was correlated with a corresponding model for heat simulation. The numerical model, as well as the established input material data, could be verified through the experimental measurements. In this particular study, the current loss in the litz wire was the dominant heat source, thus making the thermal conductivity of the SMC the most important property in this material.
文摘Improving the efficiency of induction heating of parts in the air gap of the magnetic circuit is associated with the use of surface and edge effects.Through modeling in ANSYS Electromagnetics Suite 19.2 and experimental studies identified patterns of edge effect in the heated parts.To ensure the uniformity of induction heating of small parts and reduce the soldering time,the electrical switch of soldered parts is used,which with the help of device controller forms a secondary circuit with low electrical resistance and high density of eddy currents.
