Compliance-based testing method for fatigue crack propagation rates of mixed-mode I–II cracks

Science China Technological Sciences - Mixed-mode I-II crack-based fatigue crack propagation (FCPI-II) usually occurs in engineering structures; however, no theoretical formula or effective...     

变形量对 690 合金在核电一回路水环境中电化学腐蚀行为的影响

目的研究变形量对690合金电化学行为的影响。方法采用动电位极化、电化学阻抗和高温高压浸泡实验,结合扫描电子显微镜(SEM)、X射线光谱仪(EDX)和X射线光电子能谱(XPS),研究不同变形量的690合金传热管在核电模拟液中的腐蚀行为。结果在常温常压下,50%变形量试样的自腐蚀电位比25%变形量试样正140 m V,维钝电流密度显著降低,阻抗模值高出约10倍。高温高压下浸泡后,XPS分析显示,50%变形量试样表面腐蚀产物膜中的Cr2O3含量远高于25%变形量试样,其富Cr内层致密,氧化层更厚。结论 50%变形量的690合金表面形成的钝化膜及腐蚀产物膜对基体的保护作用更强。     

核电厂应急监测计划的关键问题及探讨

应急监测计划是核电厂应急计划的重要支持性文件,是核电厂应急监测准备和响应的重要依据。本文从核电厂事故应急监测方案、监测方法、监测设施设备配置、应急监测响应、监测能力的保持、质量保证等关键问题进行分析研究,提出相关建议,为核电厂应急监测计划的制订提供参考。     

Microstructure and oxidation behaviour of Ir-rich Ir–Al binary alloys

In the current study, alloys of Ir–11Al, Ir–23Al, Ir–30Al, Ir–41Al and Ir–45Al (at.%) were prepared to investigate the microstructure and oxidation behaviour of Ir-rich Ir–Al alloys. Ir(Al)_ss and/or β-IrAl intermetallic phases were found to exist in the prepared alloys. During isothermal oxidation at 1100 °C, the Ir(Al)_ss and β-IrAl individually changed to porous and dense Al₂O₃. The microstructure of the oxide scale formed on Ir–23Al was similar to that of its former alloy which possessed a dendrite-like configuration. It was found that the mass change of Ir–45Al followed a parabolic law, showing the best oxidation resistance among the Ir–Al alloys.     

超超临界锅炉12Cr1MoVG集箱角接头再热裂纹原因分析及焊接工艺优化

针对1000 MW超超临界锅炉12Cr1MoVG集箱安装前检验发现的管座角焊缝裂纹问题,通过现场焊接接头的残余应力测试,含裂纹角焊缝试样的金相、扫描电镜及显微硬度等试验研究,结合集箱材料、结构和制造、安装的焊接及焊后热处理工艺等判定集箱角焊缝裂纹性质为再热裂纹,提出了相应的焊接及修复的工艺优化措施。实施结果表明,该措施能有效防止集箱角焊缝再热裂纹。     

国产600MW核电机组主调门油动机活塞杆断裂原因分析

某国产600MW核电机组在停堆检修过程中,发现位于汽轮机高压缸主蒸汽入口主调门油动饥活塞杆已经断裂．通过分析活塞杆的材料、显微组织、力学性能和断口等,并结合活塞杆制造的资料等信息,分析了造成活塞杆断裂的原因．     

超音速火焰喷涂NiTi合金涂层的形状记忆效应

采用超音速火焰喷涂制备超致密NiTi合金涂层,通过后续热处理获得优化相变结构,并通过压痕法分析涂层的形状记忆效应。光学显微镜及扫描电镜对NiTi合金涂层微观结构表征显示,喷涂制备态涂层由内部岛状-链状界面叠片组成,涂层致密孔隙率约为0.82%。X射线衍射分析显示,NiTi涂层制备态为全奥氏体,经时效处理析出Ni₄Ti₃相。压痕法分析表明,在制备态及时效态涂层中均获得了一定的单程及双程形状记忆效应。X射线物相分析及差示扫描量热仪对比分析揭示,时效析出的第二相粒子显著增加形状记忆效应。     

水内冷发电机定子线棒的停用保养

水内冷发电机定子线棒在停备用期间的腐蚀容易造成定子线棒的堵塞,通过分阶段实施干燥空气吹扫、真空泵除湿、充氮气保养、补充除氧水和混床离子净化等保养措施,有效减轻了停用腐蚀的不利影响,保证发电机的安全运行.     

先进核电厂可靠性保证大纲（RAP）初探

介绍美国标准审查大纲（SRP）中新增的关于可靠性保证大纲的要求，查究可靠性保证要求的演变历程，探讨先进机组可靠性保证大纲的管理要求、主要内容和审管实践及遇到的问题与思考，旨在使核电领域相关人员了解、认识、重视该工程大纲，并可作为相关工作者的参考。     

Dependence of pressure on elastic,electronic and optical properties of CeO2 and ThO2: A first principles study

The phase transformation of CeO₂ and ThO₂ from fluorite to cotunnite-type structure under pressure is predicted within the density functional theory implemented with the GGA-PW91 method, the pressure induced structural phase transition occurs at 28.9 GPa for CeO₂ and 29.8 GPa for ThO₂. These values are in excellent agreement with the experimentally measured data. The elastic, electronic and optical properties at normal as well as for high-pressure phase have been calculated, particular attention is devoted to the cotunnite phase. Further, the dependence of the elastic constants, the bulk modulus B, the energy band gaps and the dielectric function on the applied pressure are presented.