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长岭炼油厂新型催化裂化装置再生系统诱风分离器尺寸小,不能采用常规氧化铝内补保护。为上,研制成钴铬钨耐高温冲蚀保护涂层,解决了该装置的技术难题,涂层采用氧-乙炔火焰喷焊工艺制成。 相似文献
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超音速火焰喷涂具有粒子飞行速度高、涂层质量好、沉积速度快、材料选择性好以及与基体的结合强度高等优点。冲蚀是水轮机过流部件、轮船螺旋浆、泥浆泵及钻杆等的主要失效形式之一。HVOF技术制备的金属陶瓷涂层因其能显著提高金属零部件的耐冲蚀性能而受到广泛应用。本文对国内外HVOF喷涂金属陶瓷涂层的冲蚀失效行为进行综述,系统归纳了冲蚀颗粒粒径、冲蚀速度、攻角等外部因素及涂层的结合强度、孔隙率、涂层颗粒尺寸、碳化物颗粒的大小等内部因素对HVOF喷涂金属陶瓷涂层冲蚀失效行为的影响机制。并指出综合评价外部服役条件和自身性能参数对涂层冲蚀失效行为的作用机理是本领域今后研究的重点方向之一。 相似文献
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等离子喷涂隔热及抗冲蚀复合涂层是目前涂层领域的研究热点之一。综述了国内外等离子喷涂常规氧化锆、纳米氧化锆及表面钨粉抗冲蚀涂层的研究现状。指出了制备隔热及抗冲蚀复合涂层存在的问题,并展望了其发展前景。 相似文献
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环氧粉末涂层的抗冲蚀性能 总被引:5,自引:0,他引:5
在金刚砂砂浆中,用旋转圆盘式冲刷腐蚀试验机研究了流速、含砂量、砂粒粒径等环境参数对SEBF-2型熔融结合环氧粉末涂层冲蚀特性的影响,并观察了涂层形貌。实验结果表明:涂层的冲蚀率(E)与流速(V)、含砂量(C)、砂粒粒径(D)之间服从幂指数关系:E∝V^n1C^n2D^n3,n1、n2、n3的相对大小表明,流速为主要影响因素,其次为砂粒粒径,而含砂量的影响相对较小;在本文的实验条件下,临界流速约为6m/s,涂层的第一临界粒径约为80μm,第二临界粒径约为410μm。 相似文献
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以WC,ZrO2,Cr2O3和Al2O3陶瓷颗粒为增强相,镍合金粉末为基体,运用等离子喷涂技术制备四种陶瓷/镍合金复合涂层。采用冲蚀磨损试验机和正交试验方法,进行陶瓷颗粒相浓度、磨粒粒度、冲蚀角和速度对陶瓷颗粒/镍合金复合涂层抗冲蚀磨损性能影响的试验研究。采用表面形状测量仪对陶瓷颗粒/镍合金复合涂层磨损表面形貌进行测量和分析。试验结果得到WC,ZrO2,Cr2O3和Al2O3四种陶瓷颗粒/镍合金复合涂层冲蚀磨损率的经验关联式。 相似文献
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将多功能四通制造材料30CrMo钢作为基体材料,使用氩弧焊制备钴基合金HS113,625,Co-112堆焊层,采用喷焊方法制备Ni60涂层,使用超音速火焰喷涂(HVOF)方法制备WC-12Co涂层。对该5种涂层的冲蚀行为使用自制的冲蚀试验机进行了研究,分析了显微组织与显微硬度对冲蚀性能的影响及涂层冲蚀后的表面形貌。结果表明:涂层的冲蚀失重与减薄均随冲蚀时间线性增加,HS113涂层的耐冲蚀性要优于其他4种涂层的耐冲蚀性;显微组织、硬度等均会影响涂层的耐冲蚀性能。 相似文献
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水机过流面的粒子冲蚀强度分析与缓冲涂层试验 总被引:4,自引:4,他引:0
本文分析了水机过流面受粒子冲蚀过程的表面接触应力 ,讨论了表面材料特性对应力水平的影响 ,指出粒子入射速度 0 .65m/s左右时碳钢表面即发生屈服 ,采用弹性缓冲涂层可降低应力两个量级 ,文中同时介绍了这种缓冲涂层的结构和应用效果 相似文献
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Diffusion coatings are well developed for protection of nickel-based superalloys in hot and corrosive atmospheres. In the present study, aluminide coatings are produced on an alloy 600 substrate via dipping in molten aluminium. The coatings have a two-layered structure containing a dense and compact inner layer across with a porous outer layer. Thermal oxidation and hot corrosion tests showed increased resistance by production of diffusion coatings on the superalloy. Increasing the dipping time had a positive effect on the high temperature resistance of the coated alloy. 相似文献
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Investigation on an alloy steel gear-pump has been carried out to understand the effect of microstructures on corrosion and erosion behavior of the material. The alloy tool steel gear pump was designed to replace an existing pump made of grey cast iron to increase the service life to 7–8 years from 4–5 years. However, the new pump, used for dispensing hot adhesive polymer at 170 °C and 8 bar pressure, was damaged due to pitting corrosion within one year of service. Local galvanic cells were formed between M23C6 carbides and martensite matrix of steel plate of the pump in presence of sulfide ions sourced from liquid adhesive followed by anodic dissolution of martensitic matrix surrounding the carbides. As a consequence, hard carbide particles were dislodged and facilitated the pump to undergo wear rapidly. 相似文献
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低温固化有机硅耐高温涂层织物的制备 总被引:1,自引:0,他引:1
为降低有机硅树脂固化的温度和时间,利用环氧树脂对自制有机硅低聚物进行改性,并进一步在改性硅树脂中添加铝粉、高岭土及白炭黑等功能填料制备复合有硅树脂溶液,将其涂覆在玻璃纤维织物表面,最终制备出具有低温固化功能的隔热涂层玻璃纤维织物.结果表明:环氧树脂分子侧链上的仲羟基与有机硅低聚物发生了接枝反应,环氧基团的保留也为涂层过程中实现低温固化提供了条件;改性硅树脂在700℃时的残留质量为66.2%,具有良好的热稳定性;复合有机硅树脂涂层后的织物可在60℃下烘10 min,完成固化过程,烧蚀试验表明涂层后织物的隔热性能显著提高. 相似文献
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为了增强机械镀镀层的耐腐蚀性能,采用机械镀方法,以含铝5%(质量分数)的Zn-Al合金粉为原料,在Q235钢材基体表面制备了Zn-Al合金镀层。利用扫描电镜(SEM)表征了合金镀层的截面和断面形貌;采用极化曲线、电化学阻抗谱(EIS)分析了合金镀层在3.5%NaCl溶液中的电化学行为;通过中性盐雾腐蚀实验分析了合金镀层的耐蚀性,并采用XRD分析了镀层的盐雾腐蚀产物。结果表明,Zn-Al合金镀层由葫芦状的Zn-Al合金颗粒交错互嵌堆积而成,镀层颗粒之间以类似隼接的连接方式搭接“卡锁”;与机械镀Zn层相比,Zn-Al合金镀层的腐蚀电位正移了209 mV,腐蚀电流密度仅为纯Zn镀层的7.1%左右,极化电阻为纯Zn镀层的14倍;Zn-Al合金镀层的容抗弧半径明显大于纯Zn镀层的弧半径,且Qdl较纯锌层减小;纯Zn镀层出现白锈和红锈的时间分别为24和362 h,而Zn-Al合金镀层出现白锈和红锈的时间为48和504 h。Zn-Al合金镀层的耐中性盐雾腐蚀性能明显优于纯Zn镀层,合金镀层对电荷转移具有更好的抑制作用,且Zn-Al合金镀层的腐蚀产物结构致密,可增强物理屏蔽功能。 相似文献
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A new high temperature and abrasion resistant glass-ceramic coating system (based on MgO-Al2O3-TiO2 and ZnO-Al2O3-SiO2 based glass systems) for gas turbine engine components has been developed. Thermal shock resistance, adherence at 90°-bend
test and static oxidation resistance at the required working temperature (1000°C) for continuous service and abrasion resistance
are evaluated using suitable standard methods. The coating materials and the resultant coatings are characterized using differential
thermal analysis, differential thermogravimetric analysis, X-ray diffraction analysis, optical microscopy and scanning electron
microscopy. The properties evaluated clearly showed the suitability of these coatings for protection of different hot zone
components in different types of engines. XRD analysis of the coating materials and the resultant coatings showed presence
of a number of microcrystalline phases. SEM micrographs indicate strong chemical bonding at the metal-ceramic interface. Optical
micrographs showed smooth glossy impervious defect free surface finish. 相似文献
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Microstructural changes and elemental diffusion of sputtered NiCrAlY coating on the Ni-base SC superalloy were investigated. Tests were conducted by exposing coated specimens both in vacuum and in still air at 1000 °C. XRD and SEM were used to analyze phases and microstructures. EPMA was used to characterize the distribution of elements in the coating interdiffusion layers and substrates. It was found that the as-sputtered NiCrAlY coating showed homogeneous element distribution with abrupt change of constituent at the interface between the substrate and the coating. After vacuum heat treatment, microstructural and phase changes occurred in the coating because of interdiffusion between the substrate and the coating—an interdiffusion layer and two new phases emerged. After 200 h oxidation at 1000 °C in air, the interdiffusion layer thickened and a diffusion influenced layer emerged below the interdiffusion layer in the substrate. Some of the Al in the γ′-Ni3Al phase was replaced by Ta, resulting in an increase of the lattice parameter a0 of γ′ phase. 相似文献