Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《中国腐蚀与防护学报》
Abstract: The corrosion performance of Ni free and Mn alloyed high nitrogen austenitic stainless steels (HNSSs), including uniform corrosion, intergranular corrosion, crevice corrosion, pitting corrosion and repassivation,was investigated by means of immersion test and electrochemical test. The effect of cold work and sensitization treatment on the microstructure, characteristic of passive film and corrosion resistance of the HNSSs was examined. It was found that the solution-annealed (SA) HNSSs had much weaker resistance to uniform- and intergranular- corrosion compared to the SA 316LSS. The sensitization- treatment (ST) hardly affected the uniform corrosion resistance of all the steels, but resulted in rapid degradation of the resistance to intergranular-corrosion, especially for the Mo free HNSSs. The SA HNSSs had a better resistance to crevice- and pitting- corrosion than the SA 316LSS, in particular the Mo bearing HNSSs. The ST degraded the resistance to crevice- and pitting-corrosion of the HNSSs. The cold work degraded the pitting-corrosion resistance of the HNSSs in chloride- containing solutions through thinning the passive film and decreasing the stable oxides in the passive film, but it improved the repassivation ability of the HNSSs. The ST-induced precipitation of χ phase degraded the corrosion resistance and repssivation ability of the HNSSs, and such degradation became aggravated with increasing cold work degree. Furthermore, the relevant corrosion mechanism is also discussed.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract: none
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract: none
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-19 Cooperative journals: 《金属学报》
Abstract: The service degradation and life assessment of key components in light water reactor nuclear power plants (NPPs) mainly depend on the accumulation of service property data of component materials, understanding of environmental degradation mechanism, and construction of evaluation models or methods. The current ASME design fatigue code does not take full account of the interactions of environmental, loading and material's factors. In the present work, based on the corrosion fatigue tests in simulated NPPs' high temperature pressurized water, the environmental fatigue behavior and dominant mechanism of nuclear-grade low alloy steel have been investigated. A design fatigue model was constructed by taking environmentally assisted fatigue effects into account and the corresponding design curves were given for the convenience of engineering applications. The process for environmental fatigue safety assessment of NPPs' components was proposed, based on which some tentative assessment cases have been given.
Subjects: Materials Science >> Materials Science (General) submitted time 2016-11-11 Cooperative journals: 《中国腐蚀与防护学报》
Abstract:本文综述了缝隙腐蚀的主要机理、模拟研究技术及影响因素,介绍了核电材料在实际服役过程中的缝隙腐蚀问题,讨论了高温高压水环境下缝隙腐蚀研究存在的主要问题以及进一步的研究方向。
Subjects: Materials Science >> Materials Science (General) submitted time 2016-11-04 Cooperative journals: 《金属学报》
Abstract:轻水堆核电站关键设备的服役损伤与寿命评价主要基于其材料性能数据的积累、环境失效机制的理解和评价模型或方法的构建。目前广泛应用的ASME疲劳设计曲线并未充分考虑环境、载荷、材料交互作用的影响。本文通过模拟核电高温高压循环水腐蚀疲劳试验,研究了核级低合金钢环境疲劳损伤规律与控制机理,构建了一个植入环境效应的疲劳设计模型,给出了便于工程应用的环境疲劳设计曲线,并建立了核电站实际构件的环境疲劳安全评估流程,给出了尝试实施例。