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超音速电弧喷涂耐磨涂层在电站锅炉受热面上的应用 总被引:3,自引:0,他引:3
阐述了超音速电弧喷涂技术的原理、特点及其应用.为防止锅炉受热面泄漏,可在电站锅炉吹灰器吹损的管壁表面喷涂耐磨涂层.指出应用超音速电弧喷涂技术对防止锅炉受热面泄漏问题,具有重要的实际意义. 相似文献
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火电站安装过程中,锅炉受热面管子接头数量很多,要求焊工在狭窄的位置上进行全位置焊接,操作困难。为了改变这些管接头手工操作状况,节约焊接材料和保证焊接接头的质量,我们试制成功了小直径管全位置自动钨极脉冲氩弧焊管机——ZAG型TIG自动焊管机,其适用于间距不小于40毫米的锅炉受热面密排管子的自动焊接。用该自动焊机在安徽淮北电厂工程中焊接了国产20万千瓦机组的锅炉受热面管子。其中 相似文献
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电弧喷涂技术在中国的发展和应用 总被引:22,自引:4,他引:18
电弧喷涂虽然不是一项新技术,随着电弧喷涂设备的改造和完善、新型喷涂材料的不断出现以及对电弧喷涂过程和涂层机理研究的深入,特别是电弧喷涂用管状丝材的开发和应用,使电弧喷涂技术得到越来越广泛的应用,成为最具有活力的热喷涂方法之一。在中国,电弧喷涂技术已成为最有效的钢结构长效防腐手段之一,另外,电弧喷涂技术在零部件修复和表面强化、电弧喷涂制模、锅炉水冷壁的抗热腐蚀、制造防滑涂层以及减磨涂层等方面得到了广泛应用。 相似文献
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1 问题的提出电站锅炉的水冷壁、再热器、过热器和省煤器等受热面管子的管径一般为(?)32~76mm,管壁通常为3.5~8mm,属于小径薄壁管.一台200MW及大于此容量的机组,锅炉约有2万余个小径管焊接接头.根据DL5007—92“电力建设施工及验收技术规范”(火力发电厂焊接篇)标准的规定,对于锅炉受热面管子焊接接头为Ⅰ类者,除了作(?)25%射线检测外,还应作25%超声波检测.这样不仅工作量大,而且 相似文献
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本文以仲钼酸铵(优级纯)为原料,通过结合气流式雾化干燥法和微波煅烧氢还原法制备出球形、微米级、比表面积大、分散性好的钼粉。重点研究雾化造粒过程和微波煅烧氢还原阶段的升温速率对最终Mo粉的形貌、粒度以及比表面积的影响及规律。研究结果表明,控制一定的参数可以制备出球形、微米级、分散性好的钼酸铵前驱体粉末;最终Mo粉的微观形貌受升温速率的影响,升温速率越低制备的Mo粉破碎越严重,且有少量团聚现象,升温速率越高制备的Mo粉球形度越高,分散性越好;升温速率也直接影响平均粒度和比表面积,升温速率越低,平均粒度越小,而比表面积越大,升温速率越高,平均粒度相应增大,比表面减小。 相似文献
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针对火力发电厂锅炉受热面小径管对接接头超声检测的特点,阐述了小径管对接接头超声检测灵敏度补偿的原因及灵敏度补偿量测定方法。为了保证小径管对接接头超声检测的准确性、可靠性,检测前建议对灵敏度补偿量进行实际测定。 相似文献
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Presynthesized nanocrystalline Ni-20Cr powder was deposited on SA 516 and T91 boiler steels by a high-velocity oxy-fuel spraying process. Ni-20Cr powder was synthesized by the ball milling approach. The high-temperature oxidation behavior of bare and coated samples was then studied under cyclic isothermal conditions at 900 °C for 50 cycles. The kinetics of oxidation was established using weight change measurements for the bare and coated boiler steels. Uncoated and coated samples of T91 steel were exposed to the superheated zone of a power plant boiler at 750 °C under cyclic conditions for 15 cycles. Each cycle consisted of 100 h of heating followed by 1 h of cooling. Attempts were made to study the kinetics of erosion–corrosion using weight change and thickness loss data for the samples. Different characterization techniques were used to study the oxidized and eroded–corroded samples, including x-ray diffraction, scanning electron microscopy/energy-dispersive spectroscopy, and x-ray mapping analyses. The Ni-20Cr alloy powder coating was found to offer excellent oxidation resistance to the base steels and was successful in reducing the weight gain of SA 516 steel by 98.5 % and that of T91 steel by 65 %. The coating was observed to reduce the erosion–corrosion rate of T91 steel by 86 % in terms of thickness loss. This indicates that the investigated nanostructured coating can be a better choice over conventional coating for erosion–corrosion control of boiler tubes. 相似文献
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电焊锅炉钢管一般指中低压及高压锅炉用管、热交换器和压力配管,材质为碳素结构钢和合金钢。由于这些钢管的尺寸精度高、表面质量好、生产成本低,其使用范围不断扩大。国外电焊锅炉管的质量已达到无缝钢管的等效水平。结合哈尔滨钢管厂试制电焊锅炉钢管的生产过程,简介了国内产品的应用与生产情况。 相似文献
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Investigations on the Behavior of HVOF and Cold Sprayed Ni-20Cr Coating on T22 Boiler Steel in Actual Boiler Environment 总被引:1,自引:0,他引:1
Niraj Bala Harpreet Singh Satya Prakash J. Karthikeyan 《Journal of Thermal Spray Technology》2012,21(1):144-158
High temperature corrosion accompanied by erosion is a severe problem, which may result in premature failure of the boiler
tubes. One countermeasure to overcome this problem is the use of thermal spray protective coatings. In the current investigation
high velocity oxy-fuel (HVOF) and cold spray processes have been used to deposit commercial Ni-20Cr powder on T22 boiler steel.
To evaluate the performance of the coatings in actual conditions the bare as well as the coated steels were subjected to cyclic
exposures, in the superheater zone of a coal fired boiler for 15 cycles. The weight change and thickness loss data were used
to establish kinetics of the erosion-corrosion. X-ray diffraction, surface and cross-sectional field emission scanning electron
microscope/energy dispersive spectroscopy (FE-SEM/EDS) and x-ray mapping techniques were used to analyse the as-sprayed and
corroded specimens. The HVOF sprayed coating performed better than its cold sprayed counterpart in actual boiler environment. 相似文献
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“八五”期间,超高压、亚临界压力的大容量火电机组将更多地投建和运行,发电锅炉容量的增大,运行参数的提高,对电站用钢材特别是受压元件的高压锅炉管在数量、质量和规格上的要求也就更多更高。文章介绍了电站锅炉用管的需求情况、主要性能、用管系列及钢种系列,指出必须尽快改变我国高压锅炉管主要依靠进口的现状以加速高压锅炉管国产化进程,提出了相关的措施和意见。 相似文献
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简要介绍了国内外锅炉用钢情况,以及研制20MoG高压锅炉管的技术关键,钢管的化学成分设计及生产工艺。检验结果表明,该锅炉管组织、性能、尺寸精度及表面质量均达到试制协议和ASMESA209-92技术条件要求,可用于制造300MW、600MW发电机组的亚临界、超临界锅炉水冷壁、省煤器、低温过热器和中温再热器。 相似文献