A new horizontal continuous casting method with heating-cooling combined mold （HCCM） technology was explored for fabri- cating high-quality thin-wall cupronickel alloy tubes used for heat exchange pipes. The microst...A new horizontal continuous casting method with heating-cooling combined mold （HCCM） technology was explored for fabri- cating high-quality thin-wall cupronickel alloy tubes used for heat exchange pipes. The microstructure and mechanical properties of BFe 10 cupronickel alloy tubes fabricated by HCCM and traditional continuous casting （cooling mold casting） were comparatively investigated. The results show that the tube fabricated by HCCM has smooth internal and external surfaces without any defects, and its internal and external surface roughnesses are 0.64 μm and 0.85 μm, respectively. The tube could be used for subsequent cold processing without other treatments such as surface planning, milling and acid-washing. This indicates that HCCM can effectively reduce the process flow and improve the pro- duction efficiency of a BFel0 cupronickel alloy tube. The tube has columnar grains along its axial direction with a major casting texture of {012}〈 621 〉. Compared with cooling mold casting （6 = 36.5%）, HCCM can improve elongation （3 = 46.3%） by 10% with a slight loss of strength, which indicates that HCCM remarkably improves the cold extension performance of a BFe 10 cupronickel alloy tube.展开更多
The hot tensile deformation properties and microstructure evolution of high purity C71500 cupronickel alloy at 1023-1273 K and 0.0001-0.1 s^(-1)strain rates were studied by uniaxial hot tensile deformation method.Base...The hot tensile deformation properties and microstructure evolution of high purity C71500 cupronickel alloy at 1023-1273 K and 0.0001-0.1 s^(-1)strain rates were studied by uniaxial hot tensile deformation method.Based on the experimental data,the flow behavior,microstructure and fracture characteristics of the alloy were analyzed after considering the influence of different deformation parameters.The relationship between microstructure and high temperature(T≥1023 K)plasticity is discussed,and the fracture mechanism is revealed.The relationship between strain rate sensitivity coefficient and stress index and plastic deformation is discussed.The constitutive equation of the alloy is established by Johnson-Cook model.Based on the dynamic material model,the energy dissipation model is established,and Prasad’s instability criterion based on Ziegler’s expected rheological theory is used to predict the unstable region in the processing map.Processing map in hot tensile is analyzed to provide theoretical basis for different processing technology.展开更多
The corrosion behavior of cupronickel alloy immersed in the simulated seawater in or without the presence of sulfate-reducing bacteria （SRB） was studied. The results of scanning electronic microscopy and electrochem...The corrosion behavior of cupronickel alloy immersed in the simulated seawater in or without the presence of sulfate-reducing bacteria （SRB） was studied. The results of scanning electronic microscopy and electrochemical impedance spectra reveal that corrosion of the sample immersed in the simulated seawater with SRB was more serious than that immersed in the simulated seawater without SRB. The atomic force microscopy images show that after immersion for 15 days, the surface roughness of the sample in the simulated seawater with SRB was higher than that of the sample in the simulated seawater without SRB. The analysis of confocal laser scanning microscopy indicates that the average depth of the pits on the surface of the sample in the simulated seawater with SRB was almost twice deeper than that of the sample in the simulated seawater without SRB.展开更多
研究晶界工程处理过程中的冷轧变形量和再结晶退火对白铜B10合金晶界特征分布的影响,采用电子背散射衍射(EBSD)技术表征分析晶界网络的变化。结果表明:白铜B10合金经冷轧7%后在800℃退火10 min可使低ΣCSL(Coincidence site lattice,Σ...研究晶界工程处理过程中的冷轧变形量和再结晶退火对白铜B10合金晶界特征分布的影响,采用电子背散射衍射(EBSD)技术表征分析晶界网络的变化。结果表明:白铜B10合金经冷轧7%后在800℃退火10 min可使低ΣCSL(Coincidence site lattice,Σ≤29)晶界比例提高到75%以上,同时形成尺寸较大的"互有Σ3n取向关系晶粒的团簇"显微组织。当变形量小于7%时,经800℃退火后没有完全再结晶;当变形量大于7%时,低ΣCSL晶界比例和平均晶粒团簇的尺寸随冷轧变形量的增加而下降。展开更多
基金supported by the National High Technology Research and Development Program of China (No.2011BAE23B00)
文摘A new horizontal continuous casting method with heating-cooling combined mold （HCCM） technology was explored for fabri- cating high-quality thin-wall cupronickel alloy tubes used for heat exchange pipes. The microstructure and mechanical properties of BFe 10 cupronickel alloy tubes fabricated by HCCM and traditional continuous casting （cooling mold casting） were comparatively investigated. The results show that the tube fabricated by HCCM has smooth internal and external surfaces without any defects, and its internal and external surface roughnesses are 0.64 μm and 0.85 μm, respectively. The tube could be used for subsequent cold processing without other treatments such as surface planning, milling and acid-washing. This indicates that HCCM can effectively reduce the process flow and improve the pro- duction efficiency of a BFel0 cupronickel alloy tube. The tube has columnar grains along its axial direction with a major casting texture of {012}〈 621 〉. Compared with cooling mold casting （6 = 36.5%）, HCCM can improve elongation （3 = 46.3%） by 10% with a slight loss of strength, which indicates that HCCM remarkably improves the cold extension performance of a BFe 10 cupronickel alloy tube.
基金Funded by Ministry of Industry and Information Technology of the People's Republic of China(No.TC170A2KN-8)the National Natural Science Foundation of China(No.51801149)。
文摘The hot tensile deformation properties and microstructure evolution of high purity C71500 cupronickel alloy at 1023-1273 K and 0.0001-0.1 s^(-1)strain rates were studied by uniaxial hot tensile deformation method.Based on the experimental data,the flow behavior,microstructure and fracture characteristics of the alloy were analyzed after considering the influence of different deformation parameters.The relationship between microstructure and high temperature(T≥1023 K)plasticity is discussed,and the fracture mechanism is revealed.The relationship between strain rate sensitivity coefficient and stress index and plastic deformation is discussed.The constitutive equation of the alloy is established by Johnson-Cook model.Based on the dynamic material model,the energy dissipation model is established,and Prasad’s instability criterion based on Ziegler’s expected rheological theory is used to predict the unstable region in the processing map.Processing map in hot tensile is analyzed to provide theoretical basis for different processing technology.
基金financial support from National Basic Research Program of China (No.2014CB643304)the Key Technology of Corrosion Control on Wind Power Equipment Academician Workstation Project (No.2013B090400023)the National Natural Science Foundation of China (Grant No.51571202)
文摘The corrosion behavior of cupronickel alloy immersed in the simulated seawater in or without the presence of sulfate-reducing bacteria （SRB） was studied. The results of scanning electronic microscopy and electrochemical impedance spectra reveal that corrosion of the sample immersed in the simulated seawater with SRB was more serious than that immersed in the simulated seawater without SRB. The atomic force microscopy images show that after immersion for 15 days, the surface roughness of the sample in the simulated seawater with SRB was higher than that of the sample in the simulated seawater without SRB. The analysis of confocal laser scanning microscopy indicates that the average depth of the pits on the surface of the sample in the simulated seawater with SRB was almost twice deeper than that of the sample in the simulated seawater without SRB.
文摘研究晶界工程处理过程中的冷轧变形量和再结晶退火对白铜B10合金晶界特征分布的影响,采用电子背散射衍射(EBSD)技术表征分析晶界网络的变化。结果表明:白铜B10合金经冷轧7%后在800℃退火10 min可使低ΣCSL(Coincidence site lattice,Σ≤29)晶界比例提高到75%以上,同时形成尺寸较大的"互有Σ3n取向关系晶粒的团簇"显微组织。当变形量小于7%时,经800℃退火后没有完全再结晶;当变形量大于7%时,低ΣCSL晶界比例和平均晶粒团簇的尺寸随冷轧变形量的增加而下降。
