水工钢结构热喷涂金属阶梯涂层防腐技术及应用

本文在对于水工钢结构防腐技术研究中,分析一种现在最为先进的防腐技术-热喷漆阶梯涂层工艺,并且探索热喷涂金属阶梯涂层防腐技术在国家重点工程建设内的应用,经过实际应用情况发现,水工钢结构热喷涂金属阶梯涂层防腐技术所具有的防腐性能要远远优越于传统防腐技术,对于水工钢的保护时间能够有效延长,并且经济效益十分显著。     

热喷涂技术在水工钢结构防护上的应用

简述了热喷涂技术的喷涂原理、涂层结构以及形成机理,热喷涂技术的主要特点;综述了水工钢结构耐蚀性涂层的研究情况及其在钢闸门、水轮机、启闭机柱塞杆等方面的应用.     

热喷涂技术制备耐蚀涂层在炼油装备中的应用及发展前景

热喷涂技术是一门表面防护和表面强化技术,它可以在任何基材上制备耐蚀、抗磨、隔热等优良性能涂层.热喷涂技术在炼油装备中具有广泛的应用,本文介绍了热喷涂技术制备烟气轮机叶片耐高温热腐蚀涂层,油浆泵抗冲蚀涂层和钢结构、储油罐、储气罐、输油管道的长效防腐涂层.总结了目前该领域存在的问题,并对今后发展前景进行了展望.     

热喷涂技术异军突起低碳节能材料驱动未来

热喷涂技术是材料科学领域内表面工程学的重要组成部分。它是一种表面强化和表面改性的技术,约占表面工程技术的三分之一。针对热喷涂技术与涂层材料应用的开发前景,分析了热喷涂涂层材料的主要功能,介绍了常用的热喷涂涂层材料,研究了热喷涂粉末的制粉方法及质量控制,探讨了热喷涂技术与涂层材料的发展趋势,指出了涂层材料对推动热喷涂技术的发展起着非常重要的作用。     

锌及锌铝合金热喷涂涂层的腐蚀防护研究

锌及锌铝合金热喷涂涂层可以最大限度地为钢结构件和混凝土中的钢筋提供腐蚀防护。锌及锌铝合金热喷涂涂层主要的加工方式为电弧喷涂和火焰喷涂,可以在基体表面形成密封层,这就产生了一个最佳的被动与主动相结合的腐蚀防护体系,使得工件的使用寿命延长到20年。本文研究了锌及锌铝合金热喷涂涂层的微观属性和接近实际工况时的腐蚀防护特点。     

海港工程钢筋混凝土结构热喷涂阳极防护涂层技术

介绍了一种海港工程钢筋混凝土结构采用热喷涂阳极防护涂层技术来进行腐蚀防护的方法,就热喷涂防护原理、阳极涂层材料、施工工艺和质量控制等方面进行了分析和总结,也同时介绍了钢筋混凝土表面上热喷涂阳极涂层的修补技术和国外的应用实例。     

基于激光重熔的纳米陶瓷颗粒改性喷涂层的耐磨性研究

介绍了基于激光重熔技术的纳米陶瓷颗粒改性热喷涂耐磨涂层复合加工方法.以SiC纳米颗粒和WC-Co及Al2O3-TiO2热喷涂涂层为研究对象,进行了涂层改性加工试验.使用扫描电镜分析了纳米颗粒改性重熔涂层微观组织结构,并分别对热喷涂涂层、激光重熔喷涂涂层和纳米颗粒改性涂层进行了耐磨性测试.结果表明:SiC纳米颗粒能有效改善热喷涂涂层组织,并能显著提高涂层耐磨损性能.     

热喷涂技术在冶金行业的应用及其发展

阐述了热喷涂技术的优缺点及其应用领域。详细介绍了热喷涂技术在冶金领域的应用情况,以及各种涂层的特性和涂层后处理技术等,并对热喷涂技术在冶金行业的发展进行了展望。     

大力发展纳米表面工程

表面工程是当今材料科学与工程领域中一个特别重要、极具活力和备受关注的领域.纳米热喷涂开创了纳米表面工程新时代,并成为热喷涂技术新的发展方向.作者综述了纳米热喷涂涂层技术研究现状,指出未来我国应重点支持以下几个方面的研究:1.纳米热喷涂涂层成分结构设计和可控制备研究;2.有一定应用背景的或表现出优异性能的热喷涂涂层技术的...     

热喷涂WC-10Co4Cr涂层的研究现状

WC陶瓷涂层以其较高的硬度和优良的耐磨性能而被广泛的应用于各种耐磨保护涂层。文章综述了热喷涂WC-10Co4Cr涂层的主要制备方法及工艺现状;指出了其中最为适合制备WC-10Co4Cr粉末和涂层的技术方法,并总结了近年来热喷涂技术特别是超音速火焰喷涂技术制备WC-10Co4Cr涂层的主要研究进展;同时,通过对影响涂层组织和性能的主要因素和影响机理的分析,对热喷涂WC-10Co4Cr陶瓷涂层的研究趋势进行了展望,提出值得关注稀土元素对WC-10Co4Cr涂层的改性作用。     

Ceramic coatings for a corrosion-resistant nuclear waste container evaluated in simulated ground water at 90 °C

Ceramic materials provide an innovative opportunity for corrosion-resistant coatings for nuclear waste containers. Their suitability can be derived from the fully oxidized state for selected metal oxides. Ceramic coatings applied to plain carbon steel substrates by several thermal spray techniques have been exposed to 90 °C simulated ground water (at 10 times typical concentration) for nearly 6 years. Thermal spray processes examined in this work included plasma spray, high-velocity oxy fuel (HVOF), and detonation gun. Some thermal spray coatings have demonstrated superior corrosion protection for the plain carbon steel substrate. In particular, the HVOF and detonation gun thermal spray processes produced coatings with low connected porosity, which limited the growth rate of corrosion products. It was also demonstrated that these coatings resisted spallation of the coating even when an intentional flaw (which allowed for corrosion of the carbon steel substrate underneath the ceramic coating) was placed in the coating. An approach for a theoretical basis for prediction of the corrosion protection provided by ceramic coatings is also presented. The theoretical development includes the effect of the morphology and amount of the porosity within the thermal spray coating and provides a prediction of the exposure time needed to produce a crack in the ceramic coating. This article is based on a presentation made in the symposium “Effect of Processing on Materials Properties for Nuclear Waste Disposition,” November 10–11, 2003, at the TMS Fall meeting in Chicago, Illinois, under the joint auspices of the TMS Corrosion and Environmental Effects and Nuclear Materials Committees.     

热喷涂技术应用及研究进展与挑战

热喷涂作为重要的表面工程技术之一,是通过在材料表面制备材料保护涂层与功能涂层,赋予基体材料没有,但服役环境所必须的表面性能的方法。由于热喷涂可以制备从超过50%孔隙缺陷含量到接近完全致密的任意材料的涂层,基于缺陷控制可满足从可磨耗、耐高温隔热、耐磨损与耐腐蚀等不同服役要求,经过100余年的发展已经形成了包括等离子喷涂、超音速火焰喷涂、电弧喷涂、普通火焰喷涂等一系列方法,已经成为在众多产业领域,包括航天航空、交通运输、石油化工、电力能源、冶金钢铁、纺织与造纸、机械制造等,提高产品寿命与竞争力不可或缺的技术。制备可以提供耐磨损、耐环境腐蚀防护、耐高温隔热防护等保护涂层是热喷涂尤为重要的应用方面,热喷涂作为可显著提升结构零件耐磨损的涂层制备方法应用非常广泛,但在动载如冲蚀、空蚀、疲劳磨损、或高应力磨料磨损条件下,涂层材料的耐磨性能尚不能完全发挥;由于涂层总是存在一定的孔隙,难以以制备态直接用作长效耐腐蚀防护涂层,适当的封孔处理成为其用作耐腐蚀涂层的必要条件;包括以燃气轮机热障涂层为代表的耐高温隔热涂层等在航空与地面重型燃机中的应用,在欧美热喷涂市场中约占比60%,随着我国燃气轮机技术的发展,该市场潜力有望逐步得到发掘。热喷涂耐磨损涂层性能的进一步提升不仅需要开发新型硬质耐磨材料以及宽温域自润滑材料,还需要结合材料开发,发展可使粒子间结合充分的涂层制备方法,其次,基于涂层结构特征与服役性能关系控制磨损服役条件,防止源于粒子间脱落的加速磨损是确保长效磨损保护的基础。如何制备在喷涂态即可满足腐蚀介质不浸渗的致密涂层依然是热喷涂耐腐蚀涂层制备需要攻克的挑战。冷喷涂、等离子喷涂、物理气相沉积、液料热喷涂等新方法近年来发展迅速,与这些方法相配套的材料制备技术的发展将是这些新方法得到广泛应用的基础。新能源、医疗、民生、半导体等对导电、催化、生物活性、绝缘、耐刻蚀等功能涂层的需求也将有力推动热喷涂技术的发展。本文将结合目前热喷涂技术在国内外的应用现状与存在的问题,展望热喷涂技术进一步发展过程中有待解决的主要挑战性技术问题,为本领域技术人员合理认识热喷涂技术的特点,直面挑战,深入开展开发与基础研究,推动技术提供参考。     

火焰喷涂Zn-玄武岩涂层的制备及其耐腐蚀性能

以zn-玄武岩复合粉体为喂料采用火焰喷涂工艺在制备了zn-玄武岩涂层,单行线扫描喷涂实验探索研究了喷涂的距离,对涂层和基体进行了加速腐蚀试验。结果表明：火焰喷涂涂层的最佳喷涂距离为10～15cm;Zn-玄武岩涂层具有很好的耐腐蚀性,对钢铁具有很大的防护效果。     

脱硫装置搅拌器叶轮再制造及防腐耐磨涂层的应用研究

再制造具有优质、高效、节能、节材及环保的特点,目前在机械制造领域已引起高度重视,脱硫装置吸收塔搅拌器叶轮的再制造具有十分显著的经济效益及节能、节材效果。本文在分析脱硫装置吸收塔搅拌器叶轮失效机理的基础上,介绍了搅拌器叶轮在再制造中的主要工艺过程,重点阐述了搅拌器叶轮表面强化时的热喷涂涂层的材料与制备工艺的选择。研究及使...     

304不锈钢表面冷喷涂TC4钛合金涂层性能研究

采用冷喷涂技术在304不锈钢表面制备了TC4钛合金涂层,通过扫描电子显微镜观察了涂层的形貌、组织结构,并利用电化学方法研究了涂层的腐蚀电化学特征。研究结果表明,冷喷涂制备的TC4钛合金涂层致密性存在较为明显的梯度现象,靠近基体的涂层密度明显高于表面;涂层喷涂过程没有出现明显氧化现象,与基体的结合强度可达20 MPa左右;涂层的耐腐蚀性能优于304不锈钢,可大大提升不锈钢材料在海洋环境中的耐点蚀性能。     

Surface and Coating Analysis of Press‐Hardened Hot‐Dip Galvanized Steel Sheet

The use of continuous galvanized steel sheet as feedstock material for press hardening leads to components of very high strength levels with classical cathodic corrosion protection. The present work provides an insight into this technology with special focus on surface oxidation and intermetallic phase formation during the austenisation process. For that reason hot dipped galvanized 22MnB5 steel sheets, with a blank thickness of 1.5 mm and an average coating weight of 70 g m^?2, were annealed in a temperature range of 400–900°C in steps of 50°C without soaking before quenching in water. Surface and cross‐cuts were analyzed by SEM, EDX, and XRD to illustrate the phase formation and the surface changes during thermal treatment. Corrosion behavior was also studied based on electrochemical investigations and an accelerated, cyclic, automotive corrosion tests called VDA, which is a mixture of salt spray test and alternating climate test. It was found that austenisation of galvanized steel sheet causes a significant change of the coating. The generated coating still offers cathodic protection for the steel substrate and has higher corrosion resistance than standard galvanized steel sheet. Surface oxidation also occurs during the press hardening process leading to a surface covered with successively arranged layers of Al₂O₃ and ZnO, containing also further oxidized alloying elements.     

Comparative High-Temperature Corrosion Behavior of Ni-20Cr Coatings on T22 Boiler Steel Produced by HVOF, D-Gun, and Cold Spraying

To protect materials from surface degradations such as wear, corrosion, and thermal flux, a wide variety of materials can be deposited on the materials by several spraying processes. This paper examines and compares the microstructure and high-temperature corrosion of Ni-20Cr coatings deposited on T22 boiler steel by high velocity oxy-fuel (HVOF), detonation gun spray, and cold spraying techniques. The coatings’ microstructural features were characterized by means of XRD and FE-SEM/EDS analyses. Based upon the results of mass gain, XRD, and FE-SEM/EDS analyses it may be concluded that the Ni-20Cr coating sprayed by all the three techniques was effective in reducing the corrosion rate of the steel. Among the three coatings, D-gun spray coating proved to be better than HVOF-spray and cold-spray coatings.     

Evaluation of Thermal Spray Alumina Coatings on Nickel Electrode Connector for Reprocessing Applications

Electro-oxidative dissolution of the spent mixed oxide nuclear fuels with high plutonium content from prototype fast breeder reactor need to be carried out in boiling 11.5 M HNO₃. Nickel electrode connectors employed in the electrolyser of the dissolver should possess good corrosion resistance as well as good electrical conductivity. Alumina coating deposited on Ni by plasma spraying was evaluated by electrochemical polarization and impedance experiments in 11.5 M HNO₃ at room temperature. In order to improve corrosion resistance, alumina coating relatively denser than plasma spray coating was deposited over Ni by detonation gun (D-gun) spray coating. This alumina coating exhibited a high insulation resistance and the weight loss of alumina coated Ni disc was only 3% compared to 29% for bare Ni disc sample when exposed to the vapour of 11.5 M boiling HNO₃ for 12 h. However, coating delamination observed at the alumina/bond coat interface was attributed to the penetration of HNO₃ vapour through the pores in the coating. Since alumina coating deposited by D-gun technique over Ni was also found to offer only short-term protection against corrosion due to HNO₃ vapour, monolithic dense alumina sleeve fabricated through powder metallurgy route was recommended instead of coating, for better corrosion protection in HNO₃ vapour compared to thermal spray coating.     

超音速火焰喷涂 WC-Cr3C2-M 涂层性能 及其在液压支架立柱上的应用研究

分别采用电镀和超音速火焰喷涂在27SiMn钢表面制备了硬铬和WC-Cr_3C_2-M涂层,测试了两种涂层的机械性能以及磨损和腐蚀性能,并将WC-Cr_3C_2-M涂层在煤矿的液压支架的立柱上井下应用。结果表明:相对于电镀硬铬涂层,采用超音速火焰喷涂工艺制备的WC-Cr_3C_2-M涂层与基体结合强度高,孔隙率低,表现出更高的硬度、耐磨和抗腐蚀性能。WC-Cr_3C_2-M涂层在井下实际工况下防护效果显著,可以代替会给环境带来严重污染的电镀硬铬,用于煤矿井下的液压支架的表面防护。