超超临界锅炉用钢E911焊接性试验研究

超临界、超超临界机组的关键技术是多方面的,在设计和制造上都有高难技术,但热强性高、工艺性好、价格低廉的材料的开发、应用是最关键的.介绍了超超临界锅炉用钢E911材料的性能,并通过多种焊接性试验和焊接接头力学性能试验,了解了该钢的焊接性及焊接接头的机械性能,初步掌握了其焊接工艺,为工厂生产应用打下了基础.     

700℃超超临界锅炉用钢HR6W焊接接头性能的试验研究

介绍了HR6W材料的化学成分和力学性能及焊接填充材料,进行了环向对接焊接试验,焊接接头按JB/T 4730标准进行RT检测,接头做了拉伸、弯曲、冲击、硬度试验和金相分析。试验结果表明:材料焊接性能良好,接头性能能满足材料要求,焊接接头在700℃高温持久试验外推1.0×105 h强度能满足材料在700℃工况条件下长期使用运行,为700℃超超临界机组锅炉高温受热面选用材料做好了技术储备。     

SA-213T91+SA-213TP347H异种钢接头失效分析

通过对失效焊接接头进行化学分析、拉力试验、金相检验,以及对裂纹形貌进行观察,分析了超超临界火电锅炉机组SA-213T91+SA-213TP347H异种钢焊接接头的失效原因。结果表明,原始焊接接头无焊接缺陷,焊接接头的微观组织和力学性能均满足要求;失效焊接接头处同时发现蠕变和再热性质的两种裂纹,较高的工作温度和较大的纵向拉应力是导致裂纹产生的主要原因。     

C-HRA-1镍基合金的焊接工艺性能研究

试验选用2种国产镍基焊材为C-HRA-1镍基高温合金管的焊接接头填充金属,采用手工氩弧焊和热丝TIG焊2种焊接方法,对C-HRA-1进行了焊接试验,了解了C-HRA-1镍基合金的焊接性能及焊接接头的力学性能。初步掌握了C-HRA-1镍基合金的焊接工艺,为700℃先进超超临界锅炉打下了基础。     

SA-335P91耐热钢的焊接性试验研究

介绍SA -335P91耐热钢的材料性能 ,并通过多种焊接性试验和焊接接头力学性能试验 ,了解了该钢焊接性 ,初步掌握了其焊接工艺 ,为SA -335P91钢工厂生产应用打下了基础。     

超超临界火力发电厂机组主蒸汽管SA335-P92钢焊接工艺研究

简述了超超临界机组锅炉主蒸汽管SA335-P92钢的性能特点,并分析其焊接特性。为获得满足超超临界火力发电机组主蒸汽管SA335-P92钢的焊接接头性能,详细介绍了应采取的焊接工艺措施。实践证明,通过严格执行施焊工艺,控制现场施工环境,可以获得满足使用性能要求的焊接接头。     

先进超超临界燃煤电站用Haynes282合金焊接工艺

本文介绍了700℃先进超超临界燃煤电站研发中的一种候选材料Haynes282合金,通过试验确定了其小口径无缝管对接接头手工钨极氩弧焊、热丝TIG焊的焊接工艺要点及焊接接头常温力学性能。     

新焊接转子材料25Cr2Ni2MoV钢的试制及其性能试验

回顾了上汽厂汽轮机低压焊接转子材料的发展,介绍了屈服强度≥700MPa的新焊接转子材料25Cr2Ni2MoV的基本特性,通过模拟轮盘锻件试制和解剖试验,测定了新材料的显微组织、力学性能、FATT、室温断裂韧度和钢的连续冷却转变曲线,进行了时效试验、应力腐蚀试验和焊接工艺试验等,结果表明该材料具有良好的淬透性和综合性能,能满足百万等级超超临界汽轮机及核电低压焊接转子的设计和使用要求.     

T92/HR3C异种钢焊接接头蠕变断裂研究

针对采用手工氩弧焊GTAW打底,手工电弧焊SMAW焊接的T92/HR3C异种钢接头,在USC条件下对接头进行蠕变断裂加速试验,并分析蠕变断口微观形貌,研究结果表明:不同载荷条件下的蠕变断裂的位置不同;T92/HR3C异种钢焊接接头蠕变断裂属于韧窝聚集型韧性断裂;T92/HR3C异种钢焊接接头在大容量超超临界机组(USC)条件下服役是完全安全可靠的。     

窄间隙焊接技术在600MW汽轮机低压转子上的应用

简要介绍了某类型600MW大型汽轮机低压转子的焊接工艺试验和应用情况.该转子由两个轴头和两个轮盘组成,共有3务焊缝,材料为25Cr2Ni2MoV钢,材料的屈服强度大于等于700MPa,坡口设计为窄间隙坡口,采用窄间隙氩弧焊打底,窄间隙埋弧焊填充.为了研究接头的丝能,用模拟件进行了焊接试验,并测试了接头的力学性能.结果表明,接头0.2%屈服强度及延伸率均达到了转子材料规范的要求,并具有良好的冲击韧性.该焊接转子完全符合机组设计和安全运行的要求.     

海水主冷凝器焊接材料及焊接工艺试验研究

对841焊条、Ni102焊条和Cu307焊条进行研制,通过材料焊接性试验,焊缝金属化学成分的调整和力学性能试验,焊接工艺试验及焊接工艺评定等工作,最后确定焊接工艺规范和编制工艺规程指导生产。     

600MW反应堆压力容器径向支承块特厚件镍基合金焊接

600MW反应堆压力容器(RPV-600)的径向支承块的焊接存在较多的困难因素:属于异种金属焊接接头;焊接材料可焊性差;焊缝位置较深等。在多次试验、讨论后,提出了一套合理的完整的焊接规范,使焊接质量达到了规定的技术要求。重点对镍基合金的焊接性、打磨工艺等其它辅助工艺措施作了重点的研究。     

G18CrMo2-6型高中压汽缸特大裂纹补焊修复

从某厂G18CrMo2．6型高中压汽缸特大裂纹结构特征及基体材料出发，对其焊接性、变形控制进行深入分析研究，制定了相应的补焊修复方案。同时采用半热焊的方法．模拟汽缸实际焊接条件进行工艺试验，并对其焊缝组织、性能进行评定。实践结果表明，对于该汽缸特大裂纹，补焊修复方案行之有效，能满足产品技术要求．为企业挽回了巨大的经济损失。     

Material characterisation and selection for the international research project “PRIMAVERA”

The international research project “PRIMAVERA” aims to develop a physically validated prediction model for the transition temperature shift dependence (ΔT_K) of VVER-400 weld metals versus neutron fluence after reactor pressure vessel annealing. The reactor pressure vessel of VVER type has several ring welds between the forgings, characterised by large overall dimensions, structural heterogeneity and mechanical properties variations. The weld metal is a mild low-alloy steel with rather complex structure depending on chemical composition, manufacturing technology and heat treatment and the selection of the weld sample is crucial for the success of the project. A weld with high phosphorus content manufactured following standard VVER-440/230 weld technology, has been identified and selected for the project. The detailed characterisation of the selected weld in the un-irradiated condition is the first phase of the research programme and is presented in this paper. Significant phosphorus content variations through the weld could be identified; from 0.022 to 0.044 wt%. Only small variations in mechanical properties were identified; a maximum of 13 °C difference in ductile to brittle transition temperature, mainly related to the distance to the fusion boundary and the base metal. The study also showed that testing of 14 Charpy specimens is sufficient for a correct evaluation of transition temperature. A larger number of tests are required for base metal compared with the weld metal.     

Some issues in life assessment of longitudinal seam welds based on creep tests with cross-weld specimens

In order to reduce production costs, it is of great interest to use longitudinal seam welds when manufacturing large diameter pipes. The cost reduction can be as high as 30%. However, severe inservice accidents for this type of pipes working in the creep regime have occurred mainly due to mismatch in weldment creep properties.

In many cases, creep tests of cross-weld specimens, taken from the seam weld, are used to predict the behaviour of the seam weld, assuming that the creep behaviour of specimen and weldment is equivalent. Experiences of this procedure indicate that further knowledge is required before translation between specimen and component can be made.

In the present paper, both full scale seam welded pipes and cross-weld specimens are studied with the damage mechanics concept using finite element, FE, technique. The same mechanical model of multiple material zones is used for the two components. Both the influence of differences in creep properties between the weldment constituents and the size effect of the cross-weld specimen, are studied.

It is found that the cross-weld test results can not directly be translated to the full scale component. Factors such as the creep properties and the relative geometry of the weldment constituents and the size of the cross-weld specimen have to be considered when performing creep life assessment.     

劣质混煤着火燃烬特性实验研究

以某台1 000MW超超临界电站锅炉设计煤种(劣质混煤:30%原煤+60%洗中煤+10%泥煤)为研究对象,采用热重分析方法实验研究了原煤、洗中煤、泥煤、设计煤(劣质混煤)4种煤样的着火温度、着火时间、燃烧最大速率、燃烬等燃烧特性。研究表明:相同条件下,上述4种煤的着火特性由易到难依次为泥煤→混煤→原煤→洗中煤,且混煤的前期着火燃烧特性与泥煤相接近;燃烬特性由易到难依次为:原煤→混煤→洗中煤→泥煤,且混煤的燃烬特性与洗中煤的燃烬特性相接近。     

Numerical Investigation on Aeroelastic Behavior of Composite Material Plate Excited by Pulsed Air Jet

Nowadays, carbon fiber composite material is becoming more and more popular in aero engine industry due to its high specific strength and stiffness. Laminate carbon fiber composite material is widely used to manufacture the high load wide chord fan blade, containment casing, etc. The aeroelastic behavior of composite product is critical for the optimization of the product design and manufacturing. In order to explore its aeroelastic property, this paper discusses the coupled simulation of aerodynamic excitation applied on laminate composite material plate. Mechanical behavior of composite material plate is different from that of isotropic material plate such as metal plate, because it is anisotropy and has relative high mechanical damping due to resin between plies. These plates to be studied are designed using 4 different layup configurations which follow the design methods for composite fan blade. The numerical simulation of force response analysis mainly uses single frequency mechanical force input to simulate the electromagnetic shakers or other actuators, which could transmit mechanical force to the test parts. Meanwhile, pulsed air excitation is another way to "shake" the test parts. This excitation method induces aero damping into the test part and simulates the unsteady flow in aero engine, which could cause aeroelastic problems, such as flutter, forced response and non-synchronous vibration(NSV). In this study, numerical simulation using coupled method is conducted to explore the characteristics of laminate composite plates and the property of aerodynamic excitation force generated by pulsed air jet device. Modal analysis of composite plate shows that different ply stacking sequences have a significant impact on the plate vibration characteristics. Air pulse frequency and amplitude in flow field analysis are calibrated by hot wire anemometer results. As the air pulse frequency and amplitude are varied, incident angle of flow and layup configurations of plate can be analyzed in details by the simulations. Through the comparisons of all these factors, air pulse excitation property and the aeroelastic behavior of composite material plate are estimated. It would provide a possible way to guide the next-step experimental work with the pulsed air rig. The new composite fan blade design can be evaluated through the process.     

层合板复合材料性能的测试与数据处理

复合材料层合板的性能数据是进行风电叶片、机舱罩结构设计的关键参数，其中力学性能的测试是最为关键的测试。为了实现叶片生产的国产化，该文提出了叶片设计时材料测试的方法和数据处理，为今后风电复合材料部件的自主开发铺设了道路。     

精炼30Cr2Ni4MoV低压转子材料在超超临界机组上的应用

采用Ansys有限元方法计算了超超临界机组低压转子的温度场,并整理了精练30Cr2N i4MoV低压转子材料的物理化学特性。通过对两者的分析对比,认为超超临界机组的低压转子采用精练30Cr2N i4MoV完全可以满足设计要求。