INFLUENCES OF ASSOCIATED AND SEPARATE PRECIPITATION OFγ′WITH γ" ON THERMAL STRUCTURE STABILITY IN INCONEL718 TYPE ALLOYS

用透射电镜观察了Inconel718及其改型合金中的时效析出组织调整Nb,Ti,Al的含量及比例,可以得到与通常合金中γ′和γ″单独析出有所不同的γ′和γ″的复合组织及包覆组织两类析出形态、其中γ″在γ′上析出的包覆组织具有较好的高温长期时效组织稳定性过时效试验结果表明.改型合金不同于Inconel718合金γ″致δ的相转变,却以强化相溶解而使材料软化     

INCONEL718型合金中γ″和γ′的复合及单独析出对组织稳定性的影响

用透射电镜观察了Inconel718及其改型合金中的时效析出组织调整Nb,Ti,Al的含量及比例,可以得到与通常合金中γ′和γ″单独析出有所不同的γ′和γ″的复合组织及包覆组织两类析出形态、其中γ″在γ′上析出的包覆组织具有较好的高温长期时效组织稳定性过时效试验结果表明.改型合金不同于Inconel718合金γ″致δ的相转变,却以强化相溶解而使材料软化     

长时间时效对GH625合金析出相和拉伸性能的影响

采用扫描电镜、透射电镜、X射线衍射、拉伸实验研究长时时效对GH625合金析出相及其拉伸性能的影响,并采用绝热法和Rietveld全谱拟合法对合金在720℃长时时效过程中主要析出相的体积分数进行了定量分析,进一步研究了析出相的体积分数与合金拉伸性能的关系。结果表明:GH625合金在720℃长时间时效过程中存在着γ相→γ′相→γ″相→δ相的转变;随着时效时间的延长,γ″相与δ相的体积分数始终在增大,而γ′相的体积分数则先增加后减少。析出相对GH625合金的拉伸性能有较大的影响。γ′相和γ″相的析出能够提高合金的强度,但大量尺寸过大的γ″相对合金的塑性不利;大量δ相的析出和长大使得合金的强度减小,但屈服强度比有所增加,而合金塑性则大幅降低。     

一种改型Inconel718合金的组织与性能的研究

采用化学相分析、显微组织分析和显微硬度测试等方法,研究了一种改型镍基高温合金718A在标准热处理状态的显微组织和力学性能。试验结果表明,原型718合金和改型718A合金的主要析出相皆为γ″、γ′、δ、MC相。在标准热处理状态下,改型718A合金中强化相γ′和γ″的量较原型718合金明显增多,而对于组织稳定性不利的8相的析出量则较718合金少。此外,改型718A合金的显微硬度与原型合金相比有了明显的提高,因此具有广阔的应用前景。     

镍基合金的析出相及强化机制

用结构分析和性能测试方法,研究了2种镍基合金（617和625）的时效析出相及强化机制。结果表明：在760℃时效过程中,617和625合金均析出面心立方结构的M23C6碳化物和面心立方有序结构的γ′相,M23C6碳化物分布于晶界和晶内,γ′相分布于晶内。此外,625合金还析出体心四方结构的γ″相。2种合金的晶内析出相（M23C6和γ′）稳定性好,617合金的晶界析出相（M23C6）在760℃时效3000 h后聚集长大,仍为不连续分布,可阻碍晶界滑移;625合金的晶界相（γ″相）随760℃时效时间延长数量增多。M23C6作为时效态617合金的主要析出相,弥散分布于晶界和晶内,有利于析出强化,从而提高了617合金的强度和硬度。γ″相作为625合金中的强化相,γ″相与基体（γ）之间的点阵错配度大,共格应力导致的强化作用明显,导致时效态合金的高屈服强度和硬度。     

应变诱发Inconel 718合金γ″相析出和γ″→δ转变

采用X射线衍射技术测定了冷轧Inconel 718合金在810℃时效温度下γ"相和δ相的含量,研究了冷轧变形对γ″相析出和γ″→δ转变的影响.结果表明,在810℃时效,γ″相的析出达到饱和状态此时γ"→δ的转变即将发生;应变可诱发γ″相析出以及γ″→δ转变;δ相的数量与时间的关系符合Avrami方程,随冷轧变形量增加,时间指数减小,δ相析出速率增加;γ"→δ转变的数量与时间的关系也可以用Avrami方程描述.     

应变诱发Inconel718合金γ〃相析出和γ〃→δ转变

采用X射线衍射技术测定了冷轧Inconel 718合金在810℃时效温度下γ"相和δ相的含量,研究了冷轧变形对γ″相析出和γ″→δ转变的影响.结果表明,在810℃时效,γ″相的析出达到饱和状态此时γ"→δ的转变即将发生;应变可诱发γ″相析出以及γ″→δ转变;δ相的数量与时间的关系符合Avrami方程,随冷轧变形量增加,时间指数减小,δ相析出速率增加;γ"→δ转变的数量与时间的关系也可以用Avrami方程描述.     

700℃超超临界锅炉管用617B合金时效组织演变

研究了700℃超超临界锅炉管用617B合金在720℃/10 000 h、800℃/2000 h和850℃/100 h时效和不同温度50 h时效过程中组织稳定性及力学性能变化。结果表明:617B合金在10 000 h长期时效末期组织稳定性较差,γ′相粗化且晶界上有有害相析出;温度对617B合金的组织稳定性影响较大,随着温度升高γ′相急剧粗化,晶内析出相发生转变;合金的硬度主要受γ′相析出规律的影响;720℃时效过程中晶内有拉链状析出相,其种类、结构有待进一步研究。     

GH4169合金中γ′，γ″相含量比值的测定

用阳极选择性电解脱溶相分离方法及原子吸光法测定GH4169合金中δ，，NbC,(γ′ γ″）相含量，并根据析出相的类型和组成，测定不同变形量GH4169合金中γ′，γ″相含量的比值为Wγ：Wγ≈1：3。     

Mg-Gd系合金时效析出研究进展

Mg-Gd系合金的时效析出强化效果优异且析出序列及析出相在含稀土镁合金中具有一定代表性。总结了国内外Mg-Gd系合金时效析出的研究进展,阐述该系合金的时效析出动力学、析出序列及析出相、析出相强化机理等。影响Mg-Gd系合金时效析出动力学的主要因素有时效温度、Gd元素含量、晶粒尺寸、预变形量以及少量非稀土合金元素的添加等。Mg-Gd、Mg-Gd-Y(Dy)、Mg-Gd-Nd(Sm)等合金系的时效析出序列依次为β″-Mg3Gd→β′-Mg7Gd→β1-Mg3Gd→β-Mg5Gd,Mg-Gd-Zn合金时效过程中则还会有γ″-Mg70Gd15Zn15相和γ′-MgGdZn相存在。最后,对该系合金的析出强化机制和未来的发展方向进行了阐述。     

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.     

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.     

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.     

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.