注汽锅炉用水中20G和15CrMo腐蚀速度的研究

对注汽锅炉常用材料20G与15CrMo进行水质腐蚀条件下的挂片腐蚀试验,应用CMB-2510A对腐蚀速度进行分析,探讨了注汽锅炉炉管发生腐蚀的机理。结果表明:20G钢的腐蚀速度大于15CrMo钢,后者可作为20G钢的替代材料使用。     

焦化加热炉炉管腐蚀原因分析及对策

通过金相试验、扫描电镜、能谱分析以及X射线衍射分析对焦化加热炉炉管的高温腐蚀形貌、腐蚀物成分进行了分析。最终对焦化炉管的减薄原因进行了研究。结果表明,由于炉管向火面操作温度过高,且渣油、燃料和干气中含有腐蚀介质,1Cr5Mo钢管不但发生氧化腐蚀,还发生硫化腐蚀,导致炉管腐蚀加速,使炉管腐蚀减薄。     

焦化加热炉炉管腐蚀失效分析

应用扫描电子显微镜、能谱分析以及X射线衍射仪对焦化加热炉炉管的高温腐蚀形貌，腐蚀物成分以及物相进行了分析，结果表明，由于炉膛操作温度过高，且燃料中含硫，Cr5Mo钢炉管不但发生高温氧化腐蚀，还发生硫化腐蚀，使破坏加速，最终导致炉管失效.同时提出了预防措施     

热采锅炉炉管爆裂的金相变化分析

以某种规格锅炉炉管为研究对象，在炉管爆裂处的母材、撕裂碎块以及供货原材料的纵横两个方向分别取样进行分析，探讨锅炉管爆裂处的金相变化对炉管失效的影响，并给出锅炉炉管爆裂破坏的金相学原因。     

高压锅炉水冷壁管失效分析

借助于光学显微镜和扫描电镜、电子能谱仪对高压汽包锅炉水冷壁管爆破口形貌、组织以及附着的腐蚀产物成分和化学状态进行研究．结果表明，炉水中存在过量游离NaOH和水冷壁管存在局部过热是造成炉管凿槽腐蚀的两个基本原因．提出了炉水中游离碱含量的精确算法并定量分析了一级除盐水电导率与其中游离NaOH含量之间的关系及其对炉水游离碱的影响．补给水品质不良是造成炉水中游离：NaOH过高的主要原因．要防止炉管碱腐蚀就必须保持锅炉受热面清洁，控制炉水游离碱含量，避免炉膛偏燃及火焰冲蚀，消除焊瘤及其它干扰炉水流动的因素．努力提高锅炉补给水品质，将其电导率控制在适当的标准以下尤为重要．     

油田注汽锅炉炉管爆裂失效分析

为了弄清某油田注汽锅炉炉管爆裂的原因,分别对爆裂炉管的材质、爆裂炉管及其断口处的宏观形貌、显微组织及注汽锅炉水质等方面进行了全面检验,经分析得出注汽锅炉炉管爆裂是由于超温过载引起的.     

稠油加工装置加热炉炉管腐蚀研究及控制

本文通对稠油加工过程中常减压、丙烷等装置中加热炉管的腐蚀事例的分析和研究，系统地提出了造成碉油加工装置炉管腐蚀的根本原因、规律和特点，并有针对性地提出了检维期间对炉管的腐蚀检测方法，运行期间对炉管腐蚀监测方法，同时根据不同装置炉管的腐蚀程度提出了相应的腐蚀控制和防护方法，经过多年的实际应用，充分证明了所提出的腐蚀机理的正确性及腐蚀检测方法的有效性，同时有效的防腐蚀控制措施，必给装置的长周期安全运行提供了可靠的保障。     

医疗废物焚烧装置中锅炉管爆裂分析

对医疗废物焚烧装置中使用不到1年而爆裂的304锅炉管进行了宏观形貌、金相组织、断口形貌及腐蚀产物的分析.结果表明，炉管爆裂属应力腐蚀开裂.造成炉管应力腐蚀的内因为304不锈钢是对氯化物、硫化物等相当敏感的材料;外因为医疗废物焚烧时产生的高温烟气中所含氯化物、硫化物腐蚀和来自炉管的工作应力与加工应力；并提出了相应的改进建议.     

热采锅炉炉管爆裂原因分析

对热采锅炉爆裂炉管材料进行了宏观检查、化学成分、水垢X射线衍射、光学金相组织、常温力学性能、断口能谱元素分析，结果表明，因水质差致使炉管内壁结垢影响传热，炉管较长时间处于过热状态，材料的热强性降低，导致蠕变开裂。     

乙烯6号炉预热段翅片管腐蚀泄漏原因分析

对发生腐蚀穿孔的乙烯6＃炉预热段翅片管腐蚀穿孔的原因进行了分析,通过对腐蚀产物的能谱分析和金相组织分析,指出烧焦时烧焦空气窜入,引发FeS反复氧化燃烧剥落所致.是造成翅片管均匀腐蚀的主要原因.由于预热段炉管为水平安装,在裂解炉停工蒸汽吹扫过程中,残留的蒸汽冷凝成水汇集在炉管下部或凹陷处,进入炉内空气中的氧溶解在其中,从而形成了氧的腐蚀环境,使炉管因腐蚀形成的FeS保护膜遭到破坏,最终导致炉管下部穿孔.     

Enhancement of Service Life of Steam Generating Tubes in Oil-Fired Boiler for Power Generation Employing Plasma Spray Technology

The effects of Ni-50 mass% Cr alloy coating, that is plasma-sprayed onto the fire-side of steam generating tubes in a heavy oil-fired boiler, on the high temperature corrosion resistance were examined. One of the severe environments in the industrial manufacturing facilities, where thermal sprayed coatings are employed, is the high temperature corrosion such as the oxidation, sulfidation, and low melting fuel ash corrosion in the fire-side of boiler tubes. In the fossil fuel-fired steam generating boiler facilities, the degradation or failure of steam generating tubes that were derived from the contaminants in a lower grade fuel have often occurred. The situation of degradation of the water evaporator and superheater tubes and corrosion-preventing effects of plasma sprayed coating are described. The enhanced effects of plasma sprayed Ni-50 mass% Cr alloy coating for the suppression of hot corrosion failure of the steam generating tubes of boiler are summarized.     

Mechanistic aspects of carburization in oil-fired power plants

Materials degradation due to surface carburization has been recently reported in connection to failures or high corrosion rates of superheaters or reheater tubes of oil-fired and coal-fired boilers. Reducing conditions to explain carburization process of materials are hardly to expect because fuel is burned with oxygen excess to attain its complete combustion. The formation of sodium carbonate as a carburization catalyst has been proposed in order to explain carburization phenomenon in boilers, however this carburization catalyst has been rarely found in ash deposits on carburized tubes. In order to study the role of some compounds present in boiler deposits as possible carburization catalysts and the corrosion behavior of 304H-type stainless steel in boiler deposits under reducing conditions, pack-carburization experiments were carried out at 650°C by 1000 hours. Mixtures of 60 wt.% carbon and 40 wt. % of different typical compounds of boiler tube deposits were used. The experimental results show that ash deposits and several deposit compounds act as carburization enhancers, they increase carburization of the alloy if carbon is present in ash deposits. Furthermore, corrosion were detected in some cases. However, other mechanisms might be considered to explain carburization of boiler steels. Analysis of these mechanisms is presented. It is concluded that surface deposition of partially burned particles and its further burning supplying carbon monoxide to the local atmosphere is considered as the main mechanism contributing to carburization of boiler tubes.     

二次过热器炉管的腐蚀损伤分析与表征

采用金相检验、扫描电镜、三维视频系统及能谱分析等方法，对350MW火力发电机组经13万h运行后二次过热器炉管内表面严重腐蚀损伤进行了检测与表征。结果表明，该炉管内表面的损伤主要是由水中的氯离子及溶解氧作用下引起的点腐蚀所致，为此提出了相应的预防措施。     

火电厂1025T/h锅炉高温过热器爆管分析

对某电厂爆管及高过管内壁脱落的氧化皮进行了分析.结果表明：蒸汽系统内可能存在一定量的自由态氧,具备发生氧腐蚀条件,且高过管排内所生成的氧化皮呈多孔疏松状,其易脱落堵塞管体导致短时过热爆管.     

一起电站锅炉严重腐蚀的原因分析及处理措施

某电站锅炉水冷壁发生爆管泄漏,通过水冷壁厚度、材质、金相分析及腐蚀产物成分分析,确定水冷壁失效的直接原因是锅炉水质不合格导致的严重腐蚀。根据事故原因提出了具体的应对措施。     

Studies of corrosion in power plant boiler tubes by measurement of oxygen isotopes and trace elements using secondary-ion mass spectrometry

Recent advances in secondary ionization mass spectrometry (SIMS) techniques allow the resolution of differences in the natural abundances of the isotopes of ¹⁸O and ¹⁶O, and their ratio in both conducting and insulating materials. These techniques have been used in this study to measure the oxygen isotope signatures and their spatial distribution in corrosion products formed during high-temperature oxidation of steel boiler tubes from fossil-fuel power plants. The data obtained in this study are interpreted in terms of oxygen isotope fractionation between the available oxygen reservoirs and oxides formed on or within the metal. Results are presented for three different corrosion scenarios: steamside/fireside corrosion, aqueous phosphate corrosion and corrosion due to H₂ damage. Constant, but isotopically depleted values observed in magnetites formed during steamside corrosion and H₂ damage are indicative of interaction with locally derived meteoric water (which constitutes the boiler feed water). In contrast, isotope distributions in maricite (NaFePO₄) suggest equilibrium fractionation between this phase and precursor magnetite. Oxygen isotope patterns in fireside magnetites exhibit a complex zoning that requires at least two isotopically distinct species with significantly different transport rates.     

高压汽包炉水冷壁爆管原因分析

通过爆口试件的金相分析、垢样扫描电镜及能谱分析和X射线衍射分析,结合对实际运行状况的调查,确定水冷壁爆管损坏的原因是由于排污不畅和停用腐蚀导致的介质浓缩下的碱腐蚀。针对碱腐蚀的主要原因,提出了相应的处理措施。     

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 某化工厂锅炉蒸发器吊挂管在运行了5年后突然发生爆裂失效。对该吊挂管进行了化学成分分析、金相检验、扫描电镜、X射线衍射分析及力学性能测定,结果表明：吊挂管爆口附近的碳含量和力学性能均低于相关标准规定值;管外壁脱碳;内部金相组织为过热组织。这些都是由于管内壁沉积有钙盐和硅酸盐类水垢,造成管体超温运行的结果。严重沉积的水垢还导致管内壁高温氢腐蚀,壁厚由原来的6 mm减至2～3 mm,因此发生了失效爆裂。根据分析结果提出了相应的解决方案。     

余热锅炉省煤器管腐蚀原因分析

 对在役使用的余热锅炉省煤器管进行了现场取样,经化学成分分析、机械性能测试,省煤器管束符合材质要求.通过外观检验、壁厚测量、扫描电镜、能谱和X射线衍射,对省煤器管腐蚀原因进行了分析.结果表明,余热锅炉以瓦斯气作为燃料,总硫含量波动大,硫分在燃烧时绝大部分变成了SO2,其中有一部分可进一步氧化成SO3,SO3与水汽作用而在省煤器低温部位凝结成H2SO4.腐蚀产物分析证实蚀坑内腐蚀产物为硫酸铁,管外表面附着物经检测也有其它硫酸盐形式.证实管外表面蚀坑处于易于形成露点的位置管材外表面局部腐蚀是因露点腐蚀造成.露点腐蚀蚀坑深达0.9mm,并已连片出现,难以满足省煤器管使用条件.管内表面腐蚀产物主要为Fe2O3,说明管内表面受除氧水均匀腐蚀.      

四种热喷涂涂层的综合评价

对治理火电站锅炉“四管”的四种热喷涂涂层：NiCr／Cr3Ca，Ni60B，Ni60B／WC，0Cr19Ni9从线膨胀系数、硬度、结合强度、抗腐蚀性、耐磨性以及经济性进行综合评价，目的是为电站推荐更加适合治理锅炉“四管”的涂层材料。研究结果表明，推荐NiCdCr3C2作为对受热面管道进行综合治理的喷涂材料；推荐Ni60B／WC作为治理省煤器的喷涂材料；推荐0Cr19Ni9作为治理水冷壁的喷涂材料。Ni60B在利用喷涂法对受热面管道治理的过程中应慎用。