Prospects for the domestic production of large-sized cast blades and vanes for industrial gas turbines

Russian experience in the production of large-sized cast blades and vanes for industrial gas turbines is analyzed for the past decades. It is noted that the production of small- and medium-sized blades and vanes made of Russian alloys using technologies for aviation, marine, and gas-pumping turbines cannot be scaled for industrial gas turbines. It is shown that, in order to provide manufacturability under large-scale casting from domestic nickel alloys, it is necessary to solve complex problems in changing their chemical composition, to develop new casting technologies and to optimize the heat treatment modes. An experience of PAO NPO Saturn in manufacturing the blades and vanes made of ChS88U-VI and IN738-LC foundry nickel alloys for the turbines of the GTE-110 gas turbine unit is considered in detail. Potentialities for achieving adopted target parameters for the mechanical properties of working blades cast from ChS88UM-VI modified alloy are established. For the blades made of IN738-LC alloy manufactured using the existing foundry technology, a complete compliance with the requirements of normative and technical documentation has been established. Currently, in Russia, the basis of the fleet of gas turbine plants is composed by foreign turbines, and, for the implementation of the import substitution program, one can use the positive experience of PAO NPO Saturn in casting blades from IN738-LC alloy based on a reverse engineering technique. A preliminary complex of studies of the original manufacturer’s blades should be carried out, involving, first of all, the determination of geometric size using modern measurement methods as well as the studies on the chemical compositions of the used materials (base metal and protective coatings). Further, verifying the constructed calculation models based on the obtained data, one could choose available domestic materials that would meet the operating conditions of the blades according to their heat resistance and corrosion resistance.     

Field experience with the use of forged first-stage rotor blades made of EP800 nickel alloy for the GTE-45 gas turbine

We present the results from an investigation of the structure, mechanical, and heat-resistant properties the metal of forged first-stage rotor blades of the GTE-45 gas turbine of NPO Turboatom after they had been in operation for a long time at the Yakutsk district power station. It is shown that blades made of this alloy may operate for as long as 60000 h provided that they have been manufactured with good quality. Criteria for the operational reliability of EP800 alloy are developed.     

Operation experience with cast rotor blades made of Russian alloys in stationary gas turbines

The article presents the results of the analysis of operation of working blades made of cast nickel alloys applied in gas turbines for power. Russian alloys having equiaxial crystallization, i.e., TsNK-7, ChS-104, ZMI-3U, ChS-70U, ChS-88U, ZhS6K, and one foreign alloy IN738LC (for comparison) are considered.     

Estimating the influence of short-term overheatings on the structure and properties of the metal of blades made of IN 738 and IN 792 cast nickel alloys

Results from studies on analyzing the influence of overheatings with a duration of 1 h on the structure and properties of the metal of blades made of IN 738 and IN 792 cast nickel alloys are presented. Such overheatings may occur during operation of power-generating gas turbine units and cause emergency damage to them. Modern rotor blades and guide vanes have small dimensions and thin walls, due to which standard samples for determining the mechanical and heat-resistance properties cannot be cut out from them. The results of this work can be used for estimating the state of the metal of blades that have been in operation as to their microstructure.     

汽轮机末级叶片防水蚀技术研究进展

介绍了国内外汽轮机末级叶片防水蚀技术最新研究进展,其中包括镶嵌司太立合金、电火花强化、火焰淬火、高频淬火、激光处理、热喷涂、电子柬强化等,并对汽轮机末级叶片防水蚀技术的发展趋势作了展望。     

210MW汽轮机次末级叶片断裂分析及对策

通过时断裂叶片的宏观检验、金相硬度及电子显微镜扫描断口分析试验、查出断裂是由叶片进汽侧局部水蚀较重促成该部位的应力集中而引发裂纹，裂纹在金属内以疲劳形式扩展最终导致断裂，解决措施为在进汽侧端面再延续钎焊两片硬质合金并对其运行进行严格监督。     

贯流式机组桨叶与导叶全三维联合设计

为了充分反映水流经过导叶后的流态对桨叶入流的影响,本文建立了灯泡贯流式机组桨叶和导叶的全三维联合反问题计算模型。在包括桨叶和导叶的计算域中,求解联立的控制方程,同时设计得到了导叶和桨叶的空间叶型。采用联合设计和单独设计模型分别设计了一低水头贯流式机组的桨叶和导叶,并在设计工况下对其进行了全流道湍流数值模拟。性能预估结果表明,与单独设计相比,联合设计的桨叶进口边附近压力分布得到改善,导叶和桨叶段的联合损失减小,转轮效率提高。     

Estimating the repairability of blades used in gas pumping units

Results obtained from a study of the postoperation state of the blades (after they had been in operation for up to 56000 h) used in the high-pressure turbine of a GTK-25IR gas pumping unit made of ZMI-3U and In738 nickel alloys with protective coatings applied on the cuter surface of the blade and in its inner cavity are presented. It is shown that the blades can be repaired with taking into account structural and phase changes occurring in alloys and coatings. The boundary conditions regarding the possibility of carrying out repair and restoration works are determined depending on the time for which the blades have been in operation.     

Long-term strength determination for cooled blades made of monocrystalline superalloys

For the manufacture of blades for modern gas-turbine installations, monocrystalline alloys are used. Traditional methods for the calculation of stressed-deformed state and safety factors for these alloys developed and verified for polycrystalline materials need to be adjusted. This paper deals with methodological principles for an approach to the solving of the problem concerning a finite-element determination of the long-term static strength for cooled monocrystalline blades employed in gas-turbine installations based on the use of two different models (phenomenological and micromechanical) considering the inelastic deformation of monocrystalline superalloys. An analysis has been performed for the distribution of Schmid factors in the spherical triangle for primary and secondary octahedral and cubic slip systems. Calculations are performed using Larson–Miller’s parametric dependences taking into account the crystallographic orientation of the material. A determination procedure for the anisotropy coefficients of long-term strength is described based on data for different orientations. A comparative analysis of the results of finite-element calculations made using phenomenological and micromechanical (crystallographic) creep models for the long-term static strength of cooled monocrystalline blades used in a gas-turbine engine has been performed. It is shown that the location of the most loaded sections of such a blade coincide with the results of calculations according to these models. It has been found that the micromechanical deformation model results in the obtaining of the most conservative estimate for the long-term strength of turbine blades made of monocrystalline alloys. It is shown that the calculations using models for materials with isotropic properties can produce considerable errors in determining the durability of the blades. The possibility is considered for using 1D-, 2D-, and 3D-models for turbine monocrystalline blades in the determination of their durability parameters.     

铅钙锡铈合金腐蚀膜的结构和性能

在Pb Ca Sn合金基础上添加Ce作试验,探讨Ce对Pb Ca Sn合金板栅腐蚀膜导电性的改善。采用交流阻抗法、线性电位扫描法和电镜扫描等技术,研究含Ce的Pb Ca Sn合金在硫酸溶液中形成的腐蚀膜的阻抗、组成和形貌结构,并以此合金作为板栅材料制成电池,测定和比较电池在深充放循环条件下的寿命。结果表明:Ce的加入,合金的交流阻抗明显减少,Ce有效地抑制了腐蚀膜中PbO的形成,降低腐蚀膜的厚度,腐蚀膜的颗粒趋于细化均匀,从而改善了正极板栅与活性物质之间的导电性,实验电池循环寿命延长了2倍左右。     

燃煤锅炉轴流式引风机叶片耐磨涂层的应用研究

针对燃煤锅炉轴流式引风机叶片的磨损机理,设计并制备了Ni60及NiWC35喷熔层、3Cr13火焰喷涂层、LX88A电弧喷涂层、微米结构及纳米结构WC-12Co超音速火焰(HVOF)喷涂层。研究分析了不同喷涂层的组织结构、硬度及抗冲蚀磨损性能,探讨了HVOF喷涂的纳米结构WC-12Co涂层的抗冲蚀磨损机理。研究表明:HVOF喷涂的纳米结构WC-12Co涂层与普通微米结构的WC-12Co涂层相比组织结构更致密,显微硬度提高50%左右,在所有的试验涂层中具有最优良的抗冲蚀磨损性能,其耐磨性比微米WC-12Co涂层提高1倍左右,可望在轴流式引风机上得到广泛的应用。     

对角泵叶轮基本流态研究

在介绍对角泵基本特征的基础上,运用计算流体动力学方法,对一组对角泵叶轮的基本流态进行了数值分析,对不同叶片夹角的对角泵叶轮纵断面、出口断面速度分布及叶片压力面静压力分布特性进行了定性比较和定量计算.研究发现,对应于不同的叶片夹角,对角泵叶轮的能量性能差异很大.轴流泵叶片对角布置后,离心力的作用使对角泵叶轮的扬程提高.与对应的轴流泵相比,对角泵的最优效率点向小流量方向偏移,高效区变宽.过大或过小的叶片夹角都不利于叶轮效率的提高,应通过优化设计确定最优夹角.计算结果表明,叶片夹角为150°的对角泵叶轮能获得较高的流量加权平均效率.随着叶片夹角和流量的减小,对角泵叶轮的功率不是增加而是减小,功率特性由轴流泵逐步向离心泵过渡.     

厦门电厂4号汽轮机叶片断裂原因分析

厦门电厂4号汽轮机第10级叶片断裂,通过宏观特征观察、断口扫描电镜分析、叶片材料化学成分分析、微观金相检查以及硬度、冲击试验等方法,对叶片断裂原因进行分析,得出结论认为：由于叶片结构及机组抽汽和负荷的频繁变化,导致叶片异常振动,并在应力集中部位引发裂纹源,最终产生低应力高周疲劳断裂。     

百叶窗浓缩器内叶片及壁面磨损数值预测

通过数值计算方法预测了百叶窗浓缩器内叶片及壁面磨损的情况。研究了百叶窗结构、来流速度、给粉浓度等因素对浓缩器内叶片磨损的影响,提出了一些重要的防磨原则。     

汽轮机低压转子次末级叶片开裂修复

动叶片是汽轮机的重要组成部分,其可靠性和安全性直接关系到汽轮机的安全和稳定运行。汽轮机叶片的焊接修复处理时经常出现裂纹、淬硬等问题。通过采用合理的修复工艺,得到了无缺陷的连接接头,有效地解决了2Cr12NiMo1W1V新钢种叶片的焊接修复问题。     

3000r/min用1200mm钢制末级长叶片研制

应用当代最新的全三维叶片气动和强度振动解析技术,开发设计出采用高强度高硬度Cr-Ni-Nb-Mo-V钢的新一代3000r/min用1200mm末级长叶片,并进行了超音速叶栅吹风和叶根强度验证试验,采用NC集中加工和整体装配技术试制出了一级试验叶片并进行了振动调频试验,使其具有高经济性和高安全性。     

贮氢合金和氟化处理贮氢合金的MH-Ni电池

介绍了贮氢合金材料的种类,同时叙述了经过氟化处理的贮氢合金具有吸氢量大,吸氢速度快,抗毒性强,对气体有选择性和抗微粉化等性能.由氟化处理贮氢合金制成的MH-Ni电池,经过1000次放电循环后,容量仍保持初期的90%.     

我国百万千瓦级以上核电汽轮机组现状及发展

随着国家能源政策的调整,我国的核电建设已步入积极发展阶段。介绍了国内几种百万千瓦级以上核电机组的参数、容量和特点,并对百万千瓦级核电汽轮机的特点进行了分析,介绍了国内三大主机厂的核电汽轮机汽缸、转子、叶片等关键设备的型式特点,为自主开发新机型提供参考和启发。     

铅合金的组成与浇铸方法及其耐蚀性

为了提高铅合金的耐蚀性 ,研究了不同合金成分、不同浇铸方法对铅合金的显微组织及电化学耐蚀性的影响 ,发现In与Ag的加入能大幅度提高合金的耐蚀性。而在相同组成的情况下 ,真空浇铸的铅合金耐蚀性要远远好于大气条件下浇铸的铅合金     

银合金触头材料在低压电器产品中的应用

归纳了接触器、开关、断路器等低压电器产品中几种常用的合金触头,并介绍了它们的性能、特点。对这些电器产品所用的不同触头材料银镍合金、银石墨合金、银钨合金、银氧化镉合金、银氧化锡合金等的差别进行了分析,依据多年实践工作经验,总结了对不同触头材料的应用与选择。