During this research, experimental rolled homogeneous armour steel was cast, annealed and laser cut to form an appliqué plate. This Martensitic–Bainitic microstructure steel grade was used to test a novel means ...During this research, experimental rolled homogeneous armour steel was cast, annealed and laser cut to form an appliqué plate. This Martensitic–Bainitic microstructure steel grade was used to test a novel means of engineering lightweight armour. It was determined that a laser cutting speed of 1200 mm/min produced optimum hole formations with limited distortion. The array of holes acts as a double-edged solution, in that they provide weight saving of 45%, providing a protective advantage and increasing the surface area. Data collected were used to generate laser cut-edge hole projections in order to identify the optimum cutting speed, edge condition, cost and deformation performance. These parameters resulted in the generation of a surface, with less stress raising features. This can result in a distribution of stress across the wider surface. Provided that appropriate process parameters are used to generate laser cut edges, then the hardness properties of the surface can be controlled. This is due to compressive residual stresses produced in the near edge region as a result of metallurgical transformations. This way the traverse cutting speed parameter can be adjusted to alter critical surface characteristics and microstructural properties in close proximity to the cut-edge. A relationship was identified between the width of the laser HAZ and the hardness of the cut edge. It is the thickness of the HAZ that is affected by the laser process parameters which can be manipulated with adjusting the traverse cutting speed.展开更多
In order to promote the intelligent transformation and upgrading of the steel industry, intelligent technology features based on the current situation and challenges of the steel industry are discussed in this paper. ...In order to promote the intelligent transformation and upgrading of the steel industry, intelligent technology features based on the current situation and challenges of the steel industry are discussed in this paper. Based on both domestic and global research, functional analysis, reasonable positioning, and process optimization of each aspect of steel making are expounded. The current state of molten steel quality and implementation under narrow window control is analyzed. A method for maintaining stability in the narrow window control technology of steel quality is proposed, controlled by factors including composition, temperature, time, cleanliness, and consumption(raw material). Important guidance is provided for the future development of a green and intelligent steel manufacturing process.展开更多
Against the realistic background of excess production capacity, product structure imbalance, and high material and energy consumption in steel enterprises, the implementation of operation optimization for the steel ma...Against the realistic background of excess production capacity, product structure imbalance, and high material and energy consumption in steel enterprises, the implementation of operation optimization for the steel manufacturing process is essential to reduce the production cost, increase the production or energy efficiency, and improve production management. In this study, the operation optimization problem of the steel manufacturing process, which needed to go through a complex production organization from customers' orders to workshop production, was analyzed. The existing research on the operation optimization techniques, including process simulation, production planning, production scheduling, interface scheduling, and scheduling of auxiliary equipment, was reviewed. The literature review reveals that, although considerable research has been conducted to optimize the operation of steel production, these techniques are usually independent and unsystematic.Therefore, the future work related to operation optimization of the steel manufacturing process based on the integration of multi technologies and the intersection of multi disciplines were summarized.展开更多
siliconning process to manufacture 6.5% Si steel sheet has been developed. Electric components, such as transformers and reactors are made easily from 6.5% Si steel sheet. However, improved workability is desirable to...siliconning process to manufacture 6.5% Si steel sheet has been developed. Electric components, such as transformers and reactors are made easily from 6.5% Si steel sheet. However, improved workability is desirable to increase the applications. Therefore the improvement of workability of 6.5% Si steel sheet was investigated, and the results were obtained as followst: (a) workability of 6.5% Si steel sheet is deteriorated by grain boundary oxidization. (b) grain boundary oxidization can be restrained by the addition of C. Workability and magnetic properties of 6.5% Si steel sheet with C addition are discussed. Furthermore, it was found that the workability of high Si steel sheet was improved remarkably by varging the Si content gradient along the thickness without deterioration of high frequency magnetic properties. This newly developed magnetic gradient high Si steel sheet is also discussed.展开更多
The influence of two kinds of alloying processes, adding Nb (or Ti) and N-Mn alloy as well as adding Nb (or Ti) and spraying N2, on microstructures and properties of a high manganese steel has been studied. It has bee...The influence of two kinds of alloying processes, adding Nb (or Ti) and N-Mn alloy as well as adding Nb (or Ti) and spraying N2, on microstructures and properties of a high manganese steel has been studied. It has been found that adding Nb(or Ti), accompanying with N-Mn alloy, is unfavourable to microstructure compactness of the high manganese steel, but adding Nb (or Ti)and spraying N2 into the melt is good for refining austenitic grain, forming a lot of hard particles and improving microstructure compactness. The mechanical properties of the high manganese steel have relation to the content of elements Nb or Ti. Its fracture mode will turn ductile fracture into brittle cleavage fracture gradually. By X-ray and TEM analysis, it is proved that the austenite can be transformed to deformation-induced α martensite after adding a certain amount of element Nb (or Ti). The microstructure transformation of alloying high manganese steels through deformation is one of methods for strengthening austenite matrix and increasing the work-hardening rate as well as improving antiwear property.展开更多
In this paper, we use femtosecond laser pulse to scribe 304 stainless steel foil, detect the Fourier transform infrared spectrum of the sample before and after processing, confirm the "cold processing" and &...In this paper, we use femtosecond laser pulse to scribe 304 stainless steel foil, detect the Fourier transform infrared spectrum of the sample before and after processing, confirm the "cold processing" and "thermal processing" and their mutual conversion, and determine the "cold processing" parameter window. The ablation threshold and incubation coefficient of 304 stainless steel foil are calculated, and the effects of scanning speed and effective pulse number on the ablation threshold are analyzed. The ANSYS software is used to simulate the radial and axial temperature distributions of the surface on 304 stainless steel foil sample and the heat-affected zone with a femtosecond laser fluence of 10 J/cm2 and an effective number of pulses of 1 200 are obtained. In the aspect of spectral detection, the Fourier transform infrared spectra of the sample before and after processing are measured and two processing mechanisms of "cold processing" and "hot processing" are confirmed, which proves that we can achieve the conversion between "cold processing" and "hot processing" by changing the laser fluence and determine the "cold processing" laser fluence range.展开更多
Identifying factors that exert more influence on system output from data is one of the most challenging tasks in science and engineering.In this work,a sensitivity analysis of the generalized Gaussian process regressi...Identifying factors that exert more influence on system output from data is one of the most challenging tasks in science and engineering.In this work,a sensitivity analysis of the generalized Gaussian process regression(SA-GGPR)model is proposed to identify important factors of the nonlinear counting system.In SA-GGPR,the GGPR model with Poisson likelihood is adopted to describe the nonlinear counting system.The GGPR model with Poisson likelihood inherits the merits of nonparametric kernel learning and Poisson distribution,and can handle complex nonlinear counting systems.Nevertheless,understanding the relationships between model inputs and output in the GGPR model with Poisson likelihood is not readily accessible due to its nonparametric and kernel structure.SA-GGPR addresses this issue by providing a quantitative assessment of how different inputs affect the system output.The application results on a simulated nonlinear counting system and a real steel casting-rolling process have demonstrated that the proposed SA-GGPR method outperforms several state-of-the-art methods in identification accuracy.展开更多
基金the support of Swansea University during the pursuit of this research
文摘During this research, experimental rolled homogeneous armour steel was cast, annealed and laser cut to form an appliqué plate. This Martensitic–Bainitic microstructure steel grade was used to test a novel means of engineering lightweight armour. It was determined that a laser cutting speed of 1200 mm/min produced optimum hole formations with limited distortion. The array of holes acts as a double-edged solution, in that they provide weight saving of 45%, providing a protective advantage and increasing the surface area. Data collected were used to generate laser cut-edge hole projections in order to identify the optimum cutting speed, edge condition, cost and deformation performance. These parameters resulted in the generation of a surface, with less stress raising features. This can result in a distribution of stress across the wider surface. Provided that appropriate process parameters are used to generate laser cut edges, then the hardness properties of the surface can be controlled. This is due to compressive residual stresses produced in the near edge region as a result of metallurgical transformations. This way the traverse cutting speed parameter can be adjusted to alter critical surface characteristics and microstructural properties in close proximity to the cut-edge. A relationship was identified between the width of the laser HAZ and the hardness of the cut edge. It is the thickness of the HAZ that is affected by the laser process parameters which can be manipulated with adjusting the traverse cutting speed.
基金financially supported by the National Key R&D Program of China (No.2017YFB0304000)the National Natural Science Foundation of China (Nos.52074093, 51874102, 51704080, and 51674092)。
文摘In order to promote the intelligent transformation and upgrading of the steel industry, intelligent technology features based on the current situation and challenges of the steel industry are discussed in this paper. Based on both domestic and global research, functional analysis, reasonable positioning, and process optimization of each aspect of steel making are expounded. The current state of molten steel quality and implementation under narrow window control is analyzed. A method for maintaining stability in the narrow window control technology of steel quality is proposed, controlled by factors including composition, temperature, time, cleanliness, and consumption(raw material). Important guidance is provided for the future development of a green and intelligent steel manufacturing process.
基金financially supported by the National Natural Science Foundation of China (No.51734004)the National Key Research and Development Program of China (No.2017YFB0304005)the National Natural Science Foundation of China (No.51474044)。
文摘Against the realistic background of excess production capacity, product structure imbalance, and high material and energy consumption in steel enterprises, the implementation of operation optimization for the steel manufacturing process is essential to reduce the production cost, increase the production or energy efficiency, and improve production management. In this study, the operation optimization problem of the steel manufacturing process, which needed to go through a complex production organization from customers' orders to workshop production, was analyzed. The existing research on the operation optimization techniques, including process simulation, production planning, production scheduling, interface scheduling, and scheduling of auxiliary equipment, was reviewed. The literature review reveals that, although considerable research has been conducted to optimize the operation of steel production, these techniques are usually independent and unsystematic.Therefore, the future work related to operation optimization of the steel manufacturing process based on the integration of multi technologies and the intersection of multi disciplines were summarized.
文摘siliconning process to manufacture 6.5% Si steel sheet has been developed. Electric components, such as transformers and reactors are made easily from 6.5% Si steel sheet. However, improved workability is desirable to increase the applications. Therefore the improvement of workability of 6.5% Si steel sheet was investigated, and the results were obtained as followst: (a) workability of 6.5% Si steel sheet is deteriorated by grain boundary oxidization. (b) grain boundary oxidization can be restrained by the addition of C. Workability and magnetic properties of 6.5% Si steel sheet with C addition are discussed. Furthermore, it was found that the workability of high Si steel sheet was improved remarkably by varging the Si content gradient along the thickness without deterioration of high frequency magnetic properties. This newly developed magnetic gradient high Si steel sheet is also discussed.
文摘The influence of two kinds of alloying processes, adding Nb (or Ti) and N-Mn alloy as well as adding Nb (or Ti) and spraying N2, on microstructures and properties of a high manganese steel has been studied. It has been found that adding Nb(or Ti), accompanying with N-Mn alloy, is unfavourable to microstructure compactness of the high manganese steel, but adding Nb (or Ti)and spraying N2 into the melt is good for refining austenitic grain, forming a lot of hard particles and improving microstructure compactness. The mechanical properties of the high manganese steel have relation to the content of elements Nb or Ti. Its fracture mode will turn ductile fracture into brittle cleavage fracture gradually. By X-ray and TEM analysis, it is proved that the austenite can be transformed to deformation-induced α martensite after adding a certain amount of element Nb (or Ti). The microstructure transformation of alloying high manganese steels through deformation is one of methods for strengthening austenite matrix and increasing the work-hardening rate as well as improving antiwear property.
基金supported by the National Natural Science Foundation of China (No.11574159)the Open Fund of the State Key Laboratory of High Field Laser Physics,China (Shanghai Institute of Optics and Fine Mechanics)the Special Research Foundation of the Central University of Nankai University (No.63191108)。
文摘In this paper, we use femtosecond laser pulse to scribe 304 stainless steel foil, detect the Fourier transform infrared spectrum of the sample before and after processing, confirm the "cold processing" and "thermal processing" and their mutual conversion, and determine the "cold processing" parameter window. The ablation threshold and incubation coefficient of 304 stainless steel foil are calculated, and the effects of scanning speed and effective pulse number on the ablation threshold are analyzed. The ANSYS software is used to simulate the radial and axial temperature distributions of the surface on 304 stainless steel foil sample and the heat-affected zone with a femtosecond laser fluence of 10 J/cm2 and an effective number of pulses of 1 200 are obtained. In the aspect of spectral detection, the Fourier transform infrared spectra of the sample before and after processing are measured and two processing mechanisms of "cold processing" and "hot processing" are confirmed, which proves that we can achieve the conversion between "cold processing" and "hot processing" by changing the laser fluence and determine the "cold processing" laser fluence range.
基金Project supported by the National Natural Science Foundation of China(Nos.62003301 and 61833014)the Natural Science Foundation of Zhejiang Province,China(No.LQ21F030018)。
文摘Identifying factors that exert more influence on system output from data is one of the most challenging tasks in science and engineering.In this work,a sensitivity analysis of the generalized Gaussian process regression(SA-GGPR)model is proposed to identify important factors of the nonlinear counting system.In SA-GGPR,the GGPR model with Poisson likelihood is adopted to describe the nonlinear counting system.The GGPR model with Poisson likelihood inherits the merits of nonparametric kernel learning and Poisson distribution,and can handle complex nonlinear counting systems.Nevertheless,understanding the relationships between model inputs and output in the GGPR model with Poisson likelihood is not readily accessible due to its nonparametric and kernel structure.SA-GGPR addresses this issue by providing a quantitative assessment of how different inputs affect the system output.The application results on a simulated nonlinear counting system and a real steel casting-rolling process have demonstrated that the proposed SA-GGPR method outperforms several state-of-the-art methods in identification accuracy.
