In order to investigate the effect of the vacuum degree in vacuum induction melting （VIM） furnace on the mechanical properties of Ni-Fe-Cr based alloy, four samples were prepared under different conditions. The chem...In order to investigate the effect of the vacuum degree in vacuum induction melting （VIM） furnace on the mechanical properties of Ni-Fe-Cr based alloy, four samples were prepared under different conditions. The chemical analysis results show that under the argon atmosphere, there is more dissipation in Al and Ti, whereas it is reduced by establishing the vacuum atmosphere. The gas analysis results show that the oxygen and nitrogen contents of the samples decrease with increasing vacuum degree. However, there is no dissipation in the gas content of the samples in higher degree of vacuum. In addition, the thermodynamic calculations show that the probability of TiO2 and Al2O3 formation is high due to the small value of the equilibrium oxygen. Higher vacuum degree reduces the tensile and yield strength of the alloys, while it enhances the elongation and reduction of area values due to the lower amount of the inclusions and evaporation of Al and Ti under higher vacuum. On the other hand, increasing vacuum degree changes the fracture mode from brittle to ductile.展开更多
This paper analyzes the observing results of vacuum degree in the the Jialichen bridge-head experimental site .The cause of vacuum degree developing below groundwater table is pointed out. The influence of vacuum degr...This paper analyzes the observing results of vacuum degree in the the Jialichen bridge-head experimental site .The cause of vacuum degree developing below groundwater table is pointed out. The influence of vacuum degree above the ground water table on pore water pressure is discussed. The results show that vacuum degree decreases along the depth because resistance. The resistance in the PVDS is lowest, in the silt is highest. Vacuum degree below groundwater table is produced mainly by dewatering or by escaping of sealed air from the end of flexible pipe. Vacuum degree above the ground water table in the sand drains makes great effect on pore water pressure. In the silt the pore water pressure does not change with the variation of vacuum degree under membrane in a short time.展开更多
为提高造纸机真空部的自动化控制水平,提升造纸企业的成本控制能力,基于PLC和真空度传感器等硬件对变频器功率实施控制,进而实现对水泵和真空泵的动态调整,使水流量和变频器功率维持在较低水平,降低造纸机干燥部运行能耗。为实现该系统...为提高造纸机真空部的自动化控制水平,提升造纸企业的成本控制能力,基于PLC和真空度传感器等硬件对变频器功率实施控制,进而实现对水泵和真空泵的动态调整,使水流量和变频器功率维持在较低水平,降低造纸机干燥部运行能耗。为实现该系统的工业应用,提出了纸机能耗控制系统的主程序流程,同时采用WinCC(Windows Control Center,视窗控制中心)组态软件为上位机设计人机交互界面。该操作界面简洁美观、交互友好,可帮助车间工作人员实时掌握纸机真空部运行数据,合理调整真空部变频器运行功率,实现低能耗生产。展开更多
为探究不同真空度条件下爆炸焊接引起的振动特性,在5kg TNT当量球形真空爆炸容器中开展铝钢爆炸焊接实验,使用Nubox-8016振动测试仪测试了0,-30,-60,-90 k Pa 4组真空度条件下爆炸焊接过程产生的振动信号,并对容器顶部和距容器中心3m地...为探究不同真空度条件下爆炸焊接引起的振动特性,在5kg TNT当量球形真空爆炸容器中开展铝钢爆炸焊接实验,使用Nubox-8016振动测试仪测试了0,-30,-60,-90 k Pa 4组真空度条件下爆炸焊接过程产生的振动信号,并对容器顶部和距容器中心3m地面处的振动信号进行了时域和频域的分析。结果表明:容器顶部和地面测点的振动速度峰值均随容器内真空压力的升高而逐渐降低,容器结构的频率分布特征与爆炸载荷的大小没有明显关系,由爆炸容器内外气压差产生的预应力对容器结构的影响可以忽略不计。展开更多
文摘In order to investigate the effect of the vacuum degree in vacuum induction melting （VIM） furnace on the mechanical properties of Ni-Fe-Cr based alloy, four samples were prepared under different conditions. The chemical analysis results show that under the argon atmosphere, there is more dissipation in Al and Ti, whereas it is reduced by establishing the vacuum atmosphere. The gas analysis results show that the oxygen and nitrogen contents of the samples decrease with increasing vacuum degree. However, there is no dissipation in the gas content of the samples in higher degree of vacuum. In addition, the thermodynamic calculations show that the probability of TiO2 and Al2O3 formation is high due to the small value of the equilibrium oxygen. Higher vacuum degree reduces the tensile and yield strength of the alloys, while it enhances the elongation and reduction of area values due to the lower amount of the inclusions and evaporation of Al and Ti under higher vacuum. On the other hand, increasing vacuum degree changes the fracture mode from brittle to ductile.
文摘This paper analyzes the observing results of vacuum degree in the the Jialichen bridge-head experimental site .The cause of vacuum degree developing below groundwater table is pointed out. The influence of vacuum degree above the ground water table on pore water pressure is discussed. The results show that vacuum degree decreases along the depth because resistance. The resistance in the PVDS is lowest, in the silt is highest. Vacuum degree below groundwater table is produced mainly by dewatering or by escaping of sealed air from the end of flexible pipe. Vacuum degree above the ground water table in the sand drains makes great effect on pore water pressure. In the silt the pore water pressure does not change with the variation of vacuum degree under membrane in a short time.
文摘为提高造纸机真空部的自动化控制水平,提升造纸企业的成本控制能力,基于PLC和真空度传感器等硬件对变频器功率实施控制,进而实现对水泵和真空泵的动态调整,使水流量和变频器功率维持在较低水平,降低造纸机干燥部运行能耗。为实现该系统的工业应用,提出了纸机能耗控制系统的主程序流程,同时采用WinCC(Windows Control Center,视窗控制中心)组态软件为上位机设计人机交互界面。该操作界面简洁美观、交互友好,可帮助车间工作人员实时掌握纸机真空部运行数据,合理调整真空部变频器运行功率,实现低能耗生产。
文摘为探究不同真空度条件下爆炸焊接引起的振动特性,在5kg TNT当量球形真空爆炸容器中开展铝钢爆炸焊接实验,使用Nubox-8016振动测试仪测试了0,-30,-60,-90 k Pa 4组真空度条件下爆炸焊接过程产生的振动信号,并对容器顶部和距容器中心3m地面处的振动信号进行了时域和频域的分析。结果表明:容器顶部和地面测点的振动速度峰值均随容器内真空压力的升高而逐渐降低,容器结构的频率分布特征与爆炸载荷的大小没有明显关系,由爆炸容器内外气压差产生的预应力对容器结构的影响可以忽略不计。
