A systematic investigation was carried out to discuss the corrosion and tribocorrosion behaviors of Hastelloy C276 alloy sliding against Al2O3 pin in artificial seawater, using a pin-on-disk tribometer integrated with...A systematic investigation was carried out to discuss the corrosion and tribocorrosion behaviors of Hastelloy C276 alloy sliding against Al2O3 pin in artificial seawater, using a pin-on-disk tribometer integrated with a potentiostat for electrochemical control. The results show that the great decrease of open circuit potential and three orders of magnitude increase of corrosion current density occur caused by friction. There are clearly synergistic effect between corrosion and wear, resulting in corrosion-induced-wear and wear-induced-corrosion in tribocorrosion process. The contribution of pure mechanical wear to total material loss exceeds 70% in all sliding conditions, so mechanical wear is the dominant factor during tribocorrosion. For considering synergistic effect between corrosion and wear, the contribution of wear-induced-corrosion to total material loss is not very high although corrosion rate is greatly accelerated by friction. The fraction of corrosion-induced-wear to the total material loss is high and in the range of 14.6%-20.5% under all sliding conditions.展开更多
The irradiation damage in nickel-base alloy C-276 irradiated with 115 keV Ar ions from low to very high doses was investigated. Structural characterization was performed using transmission electron microscopy （TEM）,...The irradiation damage in nickel-base alloy C-276 irradiated with 115 keV Ar ions from low to very high doses was investigated. Structural characterization was performed using transmission electron microscopy （TEM）, grazing incident X-ray diffraction （GIXRD） and atomic force microscopy （AFM）. High density of interstitial type dislocation loops could be observed at a dose level of around 2.75 displacements per atom （dpa）. With the irradiation dose increased to 27.5 dpa, the average size of loops increased from 5 nm to 16 nm, while the density of the loops decreased from 1.4 × 1011/cm2 to 4.6 × 1010/cm2. When the irradiation dose reached 82.5 dpa, original grains were transformed into subgrains whose sizes observed from TEM were about 20-60 nm. The fragmentation of grains was confirmed by GIXRD. The mean subgrain size was 40 nm, which was obtained from the full width at half maximum （FWHM） of the X-ray diffraction lines using the Scherrer formula and Williamson formula. AFM micrographs showed that nanometer-sized hillocks formed at the dose of 82.5 dpa, which provided further evidence of grain fragmentation at a high irradiation dose.展开更多
建立了微波消解-电感耦合等离子体发射光谱法同时测定哈氏C-276合金中Cr、Fe、Mo、W元素含量的分析方法.采用10 m L HCl-HNO3-HF(体积比为10:1:1)混合酸溶解试样.研究了合金不同溶解方式、元素谱线的选择、背景校正等试验条件,并对仪器...建立了微波消解-电感耦合等离子体发射光谱法同时测定哈氏C-276合金中Cr、Fe、Mo、W元素含量的分析方法.采用10 m L HCl-HNO3-HF(体积比为10:1:1)混合酸溶解试样.研究了合金不同溶解方式、元素谱线的选择、背景校正等试验条件,并对仪器分析参数进行了优化,确定了最佳的试验条件,各元素分析谱线依次为Cr2 67.716 nm、Fe 238.204 nm、Mo 202.031 nm、W 209.712 nm,建立的校准曲线各元素相关系数均在0.999 5以上.实际样品分析中,加标回收率为97.8%~102.7%,重复测定结果的相对标准偏差小于1.64%(n=6),试验测定结果与镍基标准样品标准值做对照,结果表明方法准确、快速,能够满足日常生产的检测要求.展开更多
基金Project(LSL-1310)supported by the Open Project of State Key Laboratory of Solid Lubrication,ChinaProject(51171059)supported by the National Natural Science Foundation of China
文摘A systematic investigation was carried out to discuss the corrosion and tribocorrosion behaviors of Hastelloy C276 alloy sliding against Al2O3 pin in artificial seawater, using a pin-on-disk tribometer integrated with a potentiostat for electrochemical control. The results show that the great decrease of open circuit potential and three orders of magnitude increase of corrosion current density occur caused by friction. There are clearly synergistic effect between corrosion and wear, resulting in corrosion-induced-wear and wear-induced-corrosion in tribocorrosion process. The contribution of pure mechanical wear to total material loss exceeds 70% in all sliding conditions, so mechanical wear is the dominant factor during tribocorrosion. For considering synergistic effect between corrosion and wear, the contribution of wear-induced-corrosion to total material loss is not very high although corrosion rate is greatly accelerated by friction. The fraction of corrosion-induced-wear to the total material loss is high and in the range of 14.6%-20.5% under all sliding conditions.
基金supported by the National Basic Research Program of China (No. 2007CB209800)National Natural Science Foundation of China(Nos. 10775108, 11075119)the Fundamental Research Funds for the Central Universities (20102020201000013)
文摘The irradiation damage in nickel-base alloy C-276 irradiated with 115 keV Ar ions from low to very high doses was investigated. Structural characterization was performed using transmission electron microscopy （TEM）, grazing incident X-ray diffraction （GIXRD） and atomic force microscopy （AFM）. High density of interstitial type dislocation loops could be observed at a dose level of around 2.75 displacements per atom （dpa）. With the irradiation dose increased to 27.5 dpa, the average size of loops increased from 5 nm to 16 nm, while the density of the loops decreased from 1.4 × 1011/cm2 to 4.6 × 1010/cm2. When the irradiation dose reached 82.5 dpa, original grains were transformed into subgrains whose sizes observed from TEM were about 20-60 nm. The fragmentation of grains was confirmed by GIXRD. The mean subgrain size was 40 nm, which was obtained from the full width at half maximum （FWHM） of the X-ray diffraction lines using the Scherrer formula and Williamson formula. AFM micrographs showed that nanometer-sized hillocks formed at the dose of 82.5 dpa, which provided further evidence of grain fragmentation at a high irradiation dose.
