In the present study,through vertical roll pre-rolling of AZ31 magnesium alloy hot-rolled plate at room temperature,the effect of different vertical roll pre-rolling reduction on edge crack of the plate during flat ro...In the present study,through vertical roll pre-rolling of AZ31 magnesium alloy hot-rolled plate at room temperature,the effect of different vertical roll pre-rolling reduction on edge crack of the plate during flat rolling was systematically studied.The evolution of microstructure and texture in the edge and middle of the plate after vertical roll pre-rolling,heating and rolling was analyzed by using EBSD technology.The results show that during the vertical roll pre-rolling,{10–12}primary twins and{10–12}-{10–12}secondary twins dominated the edge deformation,while{10–12}primary twins dominated the middle deformation.With the increase of vertical roll pre-rolling reduction,the twin volume fraction of the edge and the middle increased,and the difference between them decreased gradually.After heating,the twin orientation caused by vertical roll pre-rolling was still maintained,and there was a significant difference in grain size between the edge and the middle.When the reduction rate of flat rolling was 30%,cracks have already appeared in the initial plate,while the vertical roll pre-rolled samples showed extremely high rolling performance.When the reduction rate of flat rolling was 50%,the 8PR sample still had no crack initiation.In addition,after flat rolling of 50%,the initial plate showed a strong basal texture,while the maximum pole density of the 8PR plate was small,and the texture distribution was very scattered,showing the characteristics of weak orientation.展开更多
The 3-dimension numerical simulation study on the electromagnetic dam used in the twin roll caster has been performed by using the edge element method. It was found that the materials and structures of the roll collar...The 3-dimension numerical simulation study on the electromagnetic dam used in the twin roll caster has been performed by using the edge element method. It was found that the materials and structures of the roll collars have great influence on the distribution of the magnetic flux density, eddy current density and the electromagnetic force in the molten pool. The conductive collars make the magnetic flux density decreased in the molten pool, but it also makes the magnetic force more uniformly, and the force in the low part of the molten pool where needs greater force have increased some what. The conductive collars make the EMD device more effective than the nonconductive collars.展开更多
The hot rolling experiment of AZ31 magnesium alloy was carried out by laying anoverlay mold at the initial temperature of 400℃.According to the Mizushima automatic plan view pattern control system(MAS)rolling theory ...The hot rolling experiment of AZ31 magnesium alloy was carried out by laying anoverlay mold at the initial temperature of 400℃.According to the Mizushima automatic plan view pattern control system(MAS)rolling theory and the cross rolling process,different reductions in the middle and edges of the magnesium alloy were realized,and the influence of the regional controlled reduction rolling on the edge cracks and microstructure gradient of the magnesium alloy were analyzed.It is shown that this rolling approach has reduced the maximum edge crack depth of the rolled piece by 56.85%,and there is a weakening tendency in the base surface texture of the strip edge,the base surface texture density drops from 23.97 to 17.48 after ordinary flat rolling.It exhibits basal texture gradients from the edge to the middle of the sheet along the RD direction,which reflected the uneven deformation of the sheets.It is suitable for the processing of metal molds that require large edge reductions such as mobile phone shells,and provided a theoretical basis for the variable thickness rolling of the magnesium alloy strip.展开更多
The finite strip method in structural analysis has been extended, and elastic-plastic large deformation spline finite strip method based on the Updated-Lagrange method (U. L. method) was established to simulate roll f...The finite strip method in structural analysis has been extended, and elastic-plastic large deformation spline finite strip method based on the Updated-Lagrange method (U. L. method) was established to simulate roll forming process of channel section with outer edge. The deformation characteristics of strip was analyzed, and the three-dimensional displacement field, strain field and stress field of deformed strip were got. The calculation example proves that the peak transverse pressing membrane strain is on the corner part of the deformed strip, and the peak longitudinal stretching strain is on the outer edge part of the deformed strip in front of rolls. In addition, the transverse deformation of the deformed strip is principal, and the longitudinal deformation is small.展开更多
随着工业互联网的蓬勃发展,工业生产需要满足用户的个性化需求.由于个性化产品规格多样种类繁多,一个高效的智能排产方法对企业的生产制造尤为重要.从部署模式来看,现有的智能排产系统可分为企业本地部署和云排产服务两类.本地排产系统...随着工业互联网的蓬勃发展,工业生产需要满足用户的个性化需求.由于个性化产品规格多样种类繁多,一个高效的智能排产方法对企业的生产制造尤为重要.从部署模式来看,现有的智能排产系统可分为企业本地部署和云排产服务两类.本地排产系统的计算与存储资源相对有限,难以满足精确排产算法的需求;而云排产系统需要大量工业核心排产数据的支撑并按需计费,计算存储与网络传输的开销使排产服务成本较高.此外,工业核心数据上传至云可能存在数据泄露的风险.针对以上问题,本文以钢铁热轧生产为例,将边缘计算技术引入智能排产,提出了一种云边协作的工业互联网排产框架(Production Scheduling based on Edge-Cloud-Collaboration,PSECC),本框架在边缘端预处理原始工业数据,保证核心生产数据保留在企业端;在云端进行算法求解,通过部署通用型求解算法又为框架赋予了可扩展性.本文基于PSECC框架设计实现了针对钢铁热轧排产任务的云边分解方法,实验证明本文提出的云边协作排产方法与常规求解器的性能相似,但是可以避免工业核心数据上云,且云端求解器的选择更加灵活.在性能方面,云排产的总排产时间是PSECC的1.4~3.7倍,其中网络传输时间是10~15倍.展开更多
基金supported by the National Natural Science Foundation of China(52075357)the national key R&D plan project(2018YFA0707301)+2 种基金the key Research Science and Technology Innovation of Shanxi Province(201803D121026)Shanxi Province Science and Technology Major Project(20181102016)Open Research Fund of State Key Laboratory of High Performance Complex Manufacturing,Central South University(Kfkt2019–03)。
文摘In the present study,through vertical roll pre-rolling of AZ31 magnesium alloy hot-rolled plate at room temperature,the effect of different vertical roll pre-rolling reduction on edge crack of the plate during flat rolling was systematically studied.The evolution of microstructure and texture in the edge and middle of the plate after vertical roll pre-rolling,heating and rolling was analyzed by using EBSD technology.The results show that during the vertical roll pre-rolling,{10–12}primary twins and{10–12}-{10–12}secondary twins dominated the edge deformation,while{10–12}primary twins dominated the middle deformation.With the increase of vertical roll pre-rolling reduction,the twin volume fraction of the edge and the middle increased,and the difference between them decreased gradually.After heating,the twin orientation caused by vertical roll pre-rolling was still maintained,and there was a significant difference in grain size between the edge and the middle.When the reduction rate of flat rolling was 30%,cracks have already appeared in the initial plate,while the vertical roll pre-rolled samples showed extremely high rolling performance.When the reduction rate of flat rolling was 50%,the 8PR sample still had no crack initiation.In addition,after flat rolling of 50%,the initial plate showed a strong basal texture,while the maximum pole density of the 8PR plate was small,and the texture distribution was very scattered,showing the characteristics of weak orientation.
基金This study was financially supported by the National Natural Science Foundation of China under the Grant No.59995440 and the Natural Science Foundation of Liaoning Province under the Grant No.2001101021.
文摘The 3-dimension numerical simulation study on the electromagnetic dam used in the twin roll caster has been performed by using the edge element method. It was found that the materials and structures of the roll collars have great influence on the distribution of the magnetic flux density, eddy current density and the electromagnetic force in the molten pool. The conductive collars make the magnetic flux density decreased in the molten pool, but it also makes the magnetic force more uniformly, and the force in the low part of the molten pool where needs greater force have increased some what. The conductive collars make the EMD device more effective than the nonconductive collars.
基金Project(52005358)supported by the National Natural Science Foundation of ChinaProjects(201901D111243,201901D111241)supported by the Natural Science Foundation of Shanxi Province,ChinaProject(2019-KF-25-05)supported by the Natural Science Foundation of Liaoning Province,China。
文摘The hot rolling experiment of AZ31 magnesium alloy was carried out by laying anoverlay mold at the initial temperature of 400℃.According to the Mizushima automatic plan view pattern control system(MAS)rolling theory and the cross rolling process,different reductions in the middle and edges of the magnesium alloy were realized,and the influence of the regional controlled reduction rolling on the edge cracks and microstructure gradient of the magnesium alloy were analyzed.It is shown that this rolling approach has reduced the maximum edge crack depth of the rolled piece by 56.85%,and there is a weakening tendency in the base surface texture of the strip edge,the base surface texture density drops from 23.97 to 17.48 after ordinary flat rolling.It exhibits basal texture gradients from the edge to the middle of the sheet along the RD direction,which reflected the uneven deformation of the sheets.It is suitable for the processing of metal molds that require large edge reductions such as mobile phone shells,and provided a theoretical basis for the variable thickness rolling of the magnesium alloy strip.
文摘The finite strip method in structural analysis has been extended, and elastic-plastic large deformation spline finite strip method based on the Updated-Lagrange method (U. L. method) was established to simulate roll forming process of channel section with outer edge. The deformation characteristics of strip was analyzed, and the three-dimensional displacement field, strain field and stress field of deformed strip were got. The calculation example proves that the peak transverse pressing membrane strain is on the corner part of the deformed strip, and the peak longitudinal stretching strain is on the outer edge part of the deformed strip in front of rolls. In addition, the transverse deformation of the deformed strip is principal, and the longitudinal deformation is small.
文摘随着工业互联网的蓬勃发展,工业生产需要满足用户的个性化需求.由于个性化产品规格多样种类繁多,一个高效的智能排产方法对企业的生产制造尤为重要.从部署模式来看,现有的智能排产系统可分为企业本地部署和云排产服务两类.本地排产系统的计算与存储资源相对有限,难以满足精确排产算法的需求;而云排产系统需要大量工业核心排产数据的支撑并按需计费,计算存储与网络传输的开销使排产服务成本较高.此外,工业核心数据上传至云可能存在数据泄露的风险.针对以上问题,本文以钢铁热轧生产为例,将边缘计算技术引入智能排产,提出了一种云边协作的工业互联网排产框架(Production Scheduling based on Edge-Cloud-Collaboration,PSECC),本框架在边缘端预处理原始工业数据,保证核心生产数据保留在企业端;在云端进行算法求解,通过部署通用型求解算法又为框架赋予了可扩展性.本文基于PSECC框架设计实现了针对钢铁热轧排产任务的云边分解方法,实验证明本文提出的云边协作排产方法与常规求解器的性能相似,但是可以避免工业核心数据上云,且云端求解器的选择更加灵活.在性能方面,云排产的总排产时间是PSECC的1.4~3.7倍,其中网络传输时间是10~15倍.
