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1.
The influences of heat treatment and test condition on the microstructure and stress rupture properties of a Ni-Mo-Cr-Fe base corrosion-resistant superalloy have been investigated in this paper. Optical microscope and scanning electron microscope were employed for the microstructure observation, and X-ray diffraction, electron probe micro-analyzer, and transmission electron microscope were used for phase determination. It was found that the grain size increased and the volume fractions of initial M6C carbides decreased along with the increase in solution treatment temperature. When tested at 650 °C/320 MPa, the stress rupture lives decreased with the increase in solution treatment temperature, but the stress rupture lives increased slightly at first and then decreased for the samples solution heat treated at 1220 °C when tested at 700 °C/240 MPa. The elongations showed the descendent trends under these two conditions. The stress rupture life and elongation for the aged samples all showed a noticeable improvement at 650 °C/320 MPa, but there was no noticeable improvement at 700 °C/240 MPa. The reasons can be attributed to the grain size, test conditions, and the initial and secondary carbides. 相似文献
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用含羟基聚醚、聚酯与芳香族异氰酸酯反应制得性能全面的单组份聚氨酯粘接剂.其物理和化学性能和贮存稳定性与反应物、NCO/OH比、反应催化剂和工艺有关.结果表明该粘接剂在胺催化剂存在时由聚醚,羟值50—100、500—700;聚酯,羟值100—150、200—250;和芳香族异氰酸酯合成而得.它有优良的性能:抗张强度7.8MPa,延伸率:240%,耐磨性2.6mg/1000转. 相似文献
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In this work,pure nickel and Ni-based nanocomposite coatings(N1-Al_2O_3,Ni-SiC and Ni-ZrO_2) were produced on steel substrate by using pulse electrodeposition technique.The industrial performance tests were conducted to evaluate the wear resistance,corrosion resistance,adhesion strength and wettability behaviour of newly developed coatings.Rolling contact ball-on-disc tribometer was used to assess anti-wear behaviour of these coatings under waterlubricated contacts.The results showed that the wear- and corrosion resistance properties of nickel alumina and Ni-SiC composite coatings significantly improved than that of pure Ni and Ni-ZrO_2 coatings.The adhesion and wettability results of Ni-Al_2O_3 composite showed better performance when compared to the rest of the coatings.The effects of incorporating nanoparticles on the surface microstructure,interface adhesion and distribution of the particles were also investigated.The coatings were characterized by using scanning electron microscopy,X-ray diffraction analysis and 3D white light interferometry.The wear failure behaviour of these coatings was further examined by post-test surface observation under optical microscope. 相似文献
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MinJoong Kim JuYoung Youn JeongHoon Lim KwangSup Eom EunAe Cho HyukSang Kwon 《International Journal of Hydrogen Energy》2018,43(24):11363-11371
High-temperature corrosion of metallic bipolar plates is a main problem to limit system reliability of molten carbonate fuel cells (MCFCs). In particular, cathode current collector (CCC) and wet-seal area in the bipolar plates suffer severe corrosion during MCFCs operation. Herein, we are trying to explore facile and cost-effective coating materials and methods to enhance corrosion resistance of CCC and wet-seal area of MCFCs. Cobalt (Co) layer was coated by using electrodeposition method for CCC, and aluminum (Al) layer was coated by using mechanical cladding method for wet-seal area. Co and Al layers were transformed into in-situ lithiated oxides, which are LiCoO2 and LiAlO2, by reacting with electrolytes without detachment. These in-situ formed oxides efficiently impede formation and growth of corrosion scales by preventing permeation of electrolytes. We believe that Co electrodeposition and Al cladding would be suitable and practical methods for making protective layers to enhance corrosion resistance of CCC and wet-seal area in the MCFCs bipolar plates. 相似文献
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A. V. Lyushinskiy E. S. Fedorova N. R. Roshan E. M. Chistov R. S. Golov 《Welding International》2017,31(10):777-778
The special features of the method of diffusion welding of corrosion-resisting steel with a palladium foil using an intermediate layer made of nickel are presented. The method can be used for producing full-strength and vacuum-tight welded joints. 相似文献
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利用两种废物合成防腐防水涂料 总被引:1,自引:0,他引:1
长期处于有腐蚀介质(液体或气体)环境中的混凝土、水泥砂浆、砖石等建筑材料,会发生化学反应,导致强度降低、表层疏松、脱皮、结构损坏等。我们利用生活废物(一次性塑制餐盒)和工业废物(粉煤灰)研制出一种具有无机和有机双重优势的复合建筑涂料,可保护混凝土等建筑材料不受腐蚀。此种涂料耐酸、耐碱、耐高温(100℃±)、耐低温(-30℃±),能在干或湿基面上施工,室内外均适用 相似文献
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《Ceramics International》2020,46(4):4215-4221
Alumina is widely used as a coating on a metal implant due to its favorable mechanical and biological properties. In this research, in order to improve mechanical and biological properties of alumina, a composition of nanoparticles of alumina (instead of microparticles) and titanium diboride micro powder is introduced. The atmospheric plasma spray (APS) technique was applied to deposit Al2O3–TiB2 on the pure titanium substrate. The properties of Al2O3–TiB2 nanocomposite coatings with various weight percent of TiB2 (20, 30 and 40 wt%) were experimentally studied. The characteristics of nanocomposite films of TiB2 (20, 30 and 40 wt%) were analyzed using Field Emission Scanning Electron Microscopy (FE-SEM), energy dispersive electron spectroscopy (EDX) and X-Ray Diffraction (XRD) tests. The XRD spectra exhibited that in addition to alumina and titanium diboride, the films contained titania. Thickness and morphology of the films were calculated from FE-SEM images and the thickness of the optimized coating (Al2O3-30 wt% TiB2) was about 30–45 μm. Also, the roughness, corrosion resistance, hardness and cytotoxicity (MTT) tests were studied. The highest of hardness and roughness of the samples were obtained from Al2O3-30 wt% TiB2. According to the obtained results from the polarization test, Al2O3-30 wt% TiB2 coating had the highest corrosion resistance (222558.9962 Ω cm2). Therefore, the toxicity of Al2O3-30 wt% TiB2 was investigated as the optimized coating and the results confirmed its non-toxicity and biocompatibility. 相似文献
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油井上广泛使用国产常规液压动力钳来快速上卸套管,在提高工作效率同时也降低了操作工人劳动强度,但也产生了套管外壁咬伤划伤的新问题。一旦在套管表面上留下明显咬伤造成套管表层的防腐层损伤,井下硫化氢等腐蚀性气体就会加速对套管腐蚀,减少套管使用寿命。 相似文献