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 2023-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract： Macroscopic analysis and corrosion product analysis of galvanized flat steel which had been in service for 13 a in substation grounding grid were made by scanning electron microscopy (SEM), energy spectrum (EDS) and X-ray diffraction (XRD). The result shows that galvanized flat steel suffered serious corrosion and corrosion products are mainly composed of FeOOH, Fe3O4, Fe2O3 and etc. The cause of the corrosion product layer is the new production of corrosion products deposition on the metal/corrosion product layer interface or the cracking. At the same time, S and Cl have great influence on the inner corrosion products. Tafel test results show that the percentage of SO42- and Cl- is 1∶2 and they have equivalent effect on the corrosion influence of galvanized Q235 carbon steel near the corrosion current peak. Result of the accelerated corrosion experiment shows that corrosion rate of galvanized Q235 carbon steel in red soil increase first and then decrease， meanwhile，the corrosion mechanism of galvanized Q235 carbon steel in this acceleration that had a good speedup was unchanged.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《材料研究学报》
Abstract： Polyurethane coatings with two kinds of sillitin, i.e. M type and Z type sillitin respectively as filler were prepared and sprayed on hot dip galvanized steel sheets. The coatings exhibited better mechanical properties than the simple polyurethane coating, i.e. the wear resistance and the hardness of the polyurethane coating may be enhanced by 57.1% and 14.5%, as well as 85.7% and 41.8% for the addition of M type and Z type sillitin respectively. The coatings with the two types of sillitin exhibited also better corrosion resistance. The reason is that two types of sillitin are of a special structure composed of micro- sized granular silica and nano- flake kaolin clay, and the sillitin possesses high amount of nanoflake, which may be beneficial to the enhancement of the permeation resistance and mechanical properties of the coatings.
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 2023-03-18 Cooperative journals: 《材料研究学报》
Abstract： The influence of flaky nickel powder as pigment on the permeation resistance of fluorocarbon based coatings was investigated by salt spray tests, EIS tests and measurement of water vapor transmission rate. The results show that among others the coating with a volume fraction 5% of flaky nickel powder exhibited the best comprehensive performance, however its resistance to water permeation degraded greatly for the coating with higher volume fraction of flaky nickel powder up to 15%.
Subjects: Materials Science >> Materials Science (General) submitted time 2016-11-14 Cooperative journals: 《中国腐蚀与防护学报》
Abstract：以 NaCl+NaHSO3为腐蚀介质，通过浸渍干湿复合循环实验及腐蚀失重分析，并利用SEM，XRD和FTIR技术，研究了Q235 碳钢和P265GH 低合金钢的大气腐蚀行为。结果表明，两种钢的腐蚀遵从相同的动力学规律,腐蚀产物中均存在大量致密的FeOOH 和非晶态FeOOH，锈层具有很好的保护性，使得腐蚀速率降低。实验开始阶段两种钢的腐蚀量基本相同，但随着腐蚀的进行两者差距增大，P265GH 低合金钢比 Q235 碳钢的失重小、锈层致密、耐腐蚀性好。
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。
Hits
Hits
Downloads
Comment