核电厂蒸汽发生器用SA213T22传热管高温氧化成膜前处理试验研究

研究了喷丸处理对蒸汽发生器SA213T22传热管表面状态及高温氧化膜的影响,采用粗糙度仪、SEM、XRD分析了喷丸处理后的传热管表面粗糙度、氧化膜形貌及成分组成。结果表明,当用粒径200目的磨料实施喷丸处理时,SA213T22传热管表面形成的氧化膜致密、均匀;磨料粒径对氧化膜的组成与结构无实质影响。     

核电厂蒸汽发生器SA213T22传热管高温氧化试验研究

基于成膜温度、氧气压力、保温时间,分析了核电厂蒸汽发生器SA213T22传热管高温氧化膜形成的影响因素。借助金相显微镜、SEM、XRD技术,摸索出了最佳的高温氧化膜成型工艺。结果表明,生长的氧化膜具有致密、均匀、Fe3O4含量高的特点。     

核安全一级SA213 T22传热管国产化研究

介绍了核电厂蒸汽发生器用安全一级SA213 T22传热管国产化制造工艺,摸索出合理的热处理工艺,并对试制的SA213 T22传热管的化学成分、金相组织和力学性能等进行了分析,开展了49928.5台时、550℃高温持久试验,外推了105h的高温持久强度极限。上述试验结果均满足设计要求,对SA213 T22传热管国产化批量生产具有指导意义。     

屏式过热器SA213T91管屏膜流焊接技术

SA213T91钢管制成的膜式壁管屏膜流焊接结束后在收弧位置出现了较多的收弧裂纹,在局部焊缝中心MT探伤发现纵向线性显示,并在后续手工气保焊返修后焊缝收弧位置MT探伤又发现了大量的线性显示。针对上述问题进行分析,找到缺陷产生原因,并提出解决措施,为SA213T91钢管制成的膜式壁管屏在大型循环流化床锅炉中的应用奠定了基础。     

水蒸汽含量对SA213T91钢650 ℃氧化行为的影响

研究了ASME213 T91钢(T91钢)650℃下在(Ar+H2O)气氛中不同含量的水蒸汽中的高温氧化行为.T91钢在5%、7%和10%Ar+H2O气氛中氧化10 h的氧化动力学曲线表明,在含5%H2O气氛中氧化时,动力学符合抛物线规律,在其余两种浓度下氧化遵从分阶段抛物线规律.随水蒸汽含量的增大,氧化速度明显增大.在T91钢表面形成了多层结构的氧化膜.氧化膜组成从外到内依次为Fe2O3,Fe3O4和(Fe,Cr)3O4.探讨了不同含量的水蒸汽对T91钢氧化行为的影响机理     

T23(P23)钢的工艺焊接性评价

超临界和超超临界锅炉发展的关键是开发具有良好高温性能和工艺性能的高强耐热钢,SA213T23和SA335P23(以下简称T23、P23)钢是国外近年来开发研制的锅炉用新型高强耐热钢。本文对T23(P23)钢的工艺焊接性进行评价,有助于该钢种的应用。     

北仑发电厂再热器异种钢焊口着色渗透探伤

1 目的我厂为国家特大型燃煤火力发电厂,现拥有两台装机容量各为600MW的发电机组。机组的锅炉及压力容器部分均为进口设备,材料及制造工艺过程均相当复杂。因此在对其进行维修检验时,很容易遇到一些令人感到棘手的问题。1994年上半年1号机组大修时,我们用GB/T12605—90“钢管环缝熔化焊对接接头射线透照工艺和质量分级”标准,对再热器制造焊口(共1860个)进行了射线检验,发现其中有32个异种钢焊口(SA213T11和SA213T22与SA213TP304H的对接焊口,采用309焊条)不合格,经挖补后再次射线检查全部合格。珠光体钢与奥氏体钢焊口存在以下缺     

NiCrB电弧喷涂层的微观组织与高温氧化行为

为提高垃圾焚烧炉过热器的抗高温氧化和磨损性能,采用两种不同硼含量的NiCrB粉芯丝材,通过电弧喷涂方法在SA213-T2钢基体表面制备涂层,并对涂层的微观组织结构、高温氧化行为和显微硬度与商用NiCrTi涂层进行对比研究。结果表明:制备的NiCrB涂层呈典型的层状结构,孔隙率约为3%,氧化物含量较低,涂层的显微硬度明显高于NiCrTi涂层。NiCrB涂层在800℃下的氧化增重明显低于基体,其中B含量较低的NiCrB涂层氧化动力学曲线呈典型的抛物线形式,表面生成了连续致密的Cr_2O_3氧化膜,有效阻止了氧向涂层内部的渗透,对基材起到较好的防护作用,抗高温氧化性能略低于NiCrTi涂层。     

SA-213T91的焊接工艺

介绍了SA－213T91的焊接工艺，根据SA－213T91的焊接性，制定了相应的焊接工艺参数。试验表明，采取焊前预热，焊后热处理的TIG焊工艺进行焊接可以减少焊接缺陷的产生。     

电站用T22及与T91管高温蒸汽氧化的失效分析

对T22、T91钢锅炉再热器管高温水蒸气氧化失效进行分析;利用能谱分析仪测试分析氧化皮截面合金元素的浓度变化.结果表明:T22、T91钢管在高温蒸汽环境下产生的氧化皮恶化其传热性能,导致管壁有一定的超温现象;氧化皮可分为双层结构,内层为含Cr的保护性氧化膜,外层主要为Fe2O3氧化物,内外层之间存在着大量的细小空洞缺陷;外氧化层有较明显的剥落,剥落的外氧化层聚集在弯头处导致管壁的过热、过烧,从而导致爆管.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Effect of Short-Time Aging on the Pitting Corrosion Behavior of a Novel Lean Duplex Stainless Steel 2002

The effect of short-time aging in the temperature range between 400 and 1000 °C on the pitting corrosion behavior and mechanical property of a novel lean duplex stainless steel(LDSS) 2002 was investigated through the potentiostatic critical pitting temperature(CPT) tests and the Charpy impact tests. Both the pitting corrosion resistance and the toughness of aged specimens degraded due to the precipitation of detrimental secondary phases and the most significant reduction of CPT and impact energy emerged at 650 °C concurrently. The CPT of LDSS 2002 specimen aged at 650 °C decreased by 28 °C, and the impact energy dropped from 69 to 29 J/cm~2 compared with the solution-annealed sample. Transmission electron microscopy characterization showed that the main precipitates in LDSS 2002 were Cr_2N and M_(23)C_6 along the ferrite–austenite grain boundaries.     

Information for Contributors

正The Transactions of Nonferrous Metals Society of China,founded in 1991 and sponsored by The Nonferrous Metals Society of China,is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology,including mineral processing,extraction metallurgy,metallic materials and heat treatments,metal working,physical metallurgy,powder metallurgy,with the emphasis     

Preface

<正>We are pleased to present this Special Issue of Transactions of Nonferrous Metals Society of China containing selected papers from the First Asian Conference on Aluminum Alloys(ACAA-2013),held in Beijing,China,13–17 October 2013.This conference has been initiated,with approval of     

Information for Contributors

The Transactions of Nonferrous Metals Society of China, founded in 1991 and sponsored by The Nonferrous Metals Society of China, is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology, including mineral processing, extraction metallurgy, metallic materials and heat treatments, metal working, physical metallurgy, powder metallurgy, with the emphasis on fundamental science. It is the unique preeminent publication in English for scientists, engineers, under/post-graduates on the field of nonferrous metals industry. This journal is covered by many famous abstract/index systems and databases such as SCI Expanded, Ei Compendex Plus, 1NSPEC, CA, METADEX, AJ and JICST.     

INTRODUCTION TO PATENTS

The invention provides a method of making a mold which can reduce SOx generation rate while preventing decrease in hardening rate in the case of using sulfuric acid for a hardener composition. The method has a mixture step in which fire-resistant particles, a hardener composition and a binder composition are mixed to obtain a composition for a mold. The hardener composition contains sulfuric acid. In the mixture step, sodium carbonate is added. A molar ratio of the sulfuric acid to the sodium carbonate is 0.5 or more and 4.0 or less.     

China Foundry Week 2014

China Foundry Week, hosted by the Foundry Institution of Chinese Mechanical Engineering Society （FICMES） each year, is a large academic event in China. It is one of the ten high-impact activities sponsored by the Chinese Mechanical Engineering Society.     

17th Conference of Hydrodynamic and Electromechanical Control Engineering Call for papers

正1.Contents In order to promote the academic exchanges and technical communication of the research in the field of fluid power transmission and control,fluid control engineering specialized committee of the Chinese Society of Theoretical and Applied Mechanics will hold the 17th Conference of Hydrodynamic and Electromechanical Control Engineering on July 27-29,2014 in Tibet,Lhasa city.     

Formulas of Tension of Continuous Rolling Process

The development of computer controlled continuous rolling process calls for a mathematical expression that can express the inequality condition of "constant flow". Tension is the link of the continuous rolling process. From the condition of dynamic equilibrium, a differential equation of tension is given out. On the basis of the physical rules established from the industrial practice and experimental studies, the law of volume constancy, the linear relation of forward slip and tension, the state equation of continuous rolling, the formula of dynamic tension, and the formula of static tension have been obtained. These formulae reflect the functional relations between tensions, thickness, roll velocity, and time in the continuous rolling process. It is implied that the continuous rolling process is a gradually steady, controllable, and measurable dynamic system. An assumption of predicting the thickness of a steel plate using these tension formulae is also put forward.