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
The elemental micro-segregation characteristic within the weld zone for ytterbium fiber laser welded Hastelloy C-276sheet was investigated. The analysis of segregation ratio and equilibrium distribution coefficient of...The elemental micro-segregation characteristic within the weld zone for ytterbium fiber laser welded Hastelloy C-276sheet was investigated. The analysis of segregation ratio and equilibrium distribution coefficient of elements, determined throughEDS data, indicate the reduction in micro-segregation of elements compared with the previous reported literatures for laser weldedHastelloy C-276. High melting efficiency of ytterbium fiber laser, reduction in the amount of linear heat input, and high cooling rateof the mushy zone lead to the reduction in micro-segregation. The melting efficiency of ytterbium fiber laser for welding of HastelloyC-276 of 64% is higher than that （48%） of conventional welding methods. High melting efficiency leads to the reduction in the linearheat input required for welding. Hence, in the present investigation, the same was found to substantially reduce as compared to theprevious reported literature. The cooling rate from liquidus temperature to solidus temperature at the weld centerline was found to bein the order of 10^3℃/s. Cellular dendritic substructure that constituted for lower micro-segregation was formed at the weldcenterline.展开更多
To better understand the hot deformation behaviors of Hastelloy C-276 alloy under elevated temperatures,hot tensile tests were carried out in the temperature range of 1223−1423 K and the strain rate range of 0.01−10 s...To better understand the hot deformation behaviors of Hastelloy C-276 alloy under elevated temperatures,hot tensile tests were carried out in the temperature range of 1223−1423 K and the strain rate range of 0.01−10 s^−1,respectively.Based on the modified Zerilli−Armstrong,modified Johnson-Cook,and strain-compensated Arrheniustype models,three constitutive equations were established to describe the high-temperature flow stress of this alloy.Meanwhile,the predictability of the obtained models was evaluated by the calculation of correlation coefficients(r)and absolute errors(Δ),where the values of r for the modified Zerilli−Armstrong,Johnson−Cook,and Arrhenius-type constitutive models were computed to be 0.935,0.968 and 0.984,and the values ofΔwere calculated to be 13.4%,10.5%and 6.7%,respectively.Moreover,the experimental and predicted flow stresses were compared in the strain range of 0.1−0.5,the results further indicated that the obtained modified Arrhenius-type model possessed better predictability on hot flow behavior of Hastelloy C-276.展开更多
以集束拉拔法生产的C-276合金纤维为原料,经过纤维剪切、湿法成网、叠配毡等工序制备出纤维毡坯料,按照正交法设计出的实验方案,采用真空加压烧结法制备出C-276合金纤维毡样品,研究了烧结温度、保温时间及加压压力对纤维毡泡点压力损失...以集束拉拔法生产的C-276合金纤维为原料,经过纤维剪切、湿法成网、叠配毡等工序制备出纤维毡坯料,按照正交法设计出的实验方案,采用真空加压烧结法制备出C-276合金纤维毡样品,研究了烧结温度、保温时间及加压压力对纤维毡泡点压力损失率的影响。结果表明:烧结温度是影响泡点压力损失率的最显著因素;哈氏C-276合金纤维毡的最佳烧结工艺是烧结温度1 150℃,保温4.5 h,加压0.8 k Pa。展开更多
文摘The elemental micro-segregation characteristic within the weld zone for ytterbium fiber laser welded Hastelloy C-276sheet was investigated. The analysis of segregation ratio and equilibrium distribution coefficient of elements, determined throughEDS data, indicate the reduction in micro-segregation of elements compared with the previous reported literatures for laser weldedHastelloy C-276. High melting efficiency of ytterbium fiber laser, reduction in the amount of linear heat input, and high cooling rateof the mushy zone lead to the reduction in micro-segregation. The melting efficiency of ytterbium fiber laser for welding of HastelloyC-276 of 64% is higher than that （48%） of conventional welding methods. High melting efficiency leads to the reduction in the linearheat input required for welding. Hence, in the present investigation, the same was found to substantially reduce as compared to theprevious reported literature. The cooling rate from liquidus temperature to solidus temperature at the weld centerline was found to bein the order of 10^3℃/s. Cellular dendritic substructure that constituted for lower micro-segregation was formed at the weldcenterline.
基金Project(ZZYJKT2018-06)supported by the State Key Laboratory of High Performance Complex Manufacturing of Central South University,ChinaProject(2019zzts525)supported by the Fundamental Research Funds for the Central Universities of Central South University of China。
文摘To better understand the hot deformation behaviors of Hastelloy C-276 alloy under elevated temperatures,hot tensile tests were carried out in the temperature range of 1223−1423 K and the strain rate range of 0.01−10 s^−1,respectively.Based on the modified Zerilli−Armstrong,modified Johnson-Cook,and strain-compensated Arrheniustype models,three constitutive equations were established to describe the high-temperature flow stress of this alloy.Meanwhile,the predictability of the obtained models was evaluated by the calculation of correlation coefficients(r)and absolute errors(Δ),where the values of r for the modified Zerilli−Armstrong,Johnson−Cook,and Arrhenius-type constitutive models were computed to be 0.935,0.968 and 0.984,and the values ofΔwere calculated to be 13.4%,10.5%and 6.7%,respectively.Moreover,the experimental and predicted flow stresses were compared in the strain range of 0.1−0.5,the results further indicated that the obtained modified Arrhenius-type model possessed better predictability on hot flow behavior of Hastelloy C-276.
文摘以集束拉拔法生产的C-276合金纤维为原料,经过纤维剪切、湿法成网、叠配毡等工序制备出纤维毡坯料,按照正交法设计出的实验方案,采用真空加压烧结法制备出C-276合金纤维毡样品,研究了烧结温度、保温时间及加压压力对纤维毡泡点压力损失率的影响。结果表明:烧结温度是影响泡点压力损失率的最显著因素;哈氏C-276合金纤维毡的最佳烧结工艺是烧结温度1 150℃,保温4.5 h,加压0.8 k Pa。
