引风机叶轮焊接变形控制及矫正

通过分析与试验对引风机叶轮焊接变形规律进行了探讨，采用较为合理的焊接工艺措施，有效地控制了叶轮焊接变形，并对残余焊接变形进行了矫正，很好地保证了产品设计要求。     

大型离心压缩机焊接叶轮出口流道变形数值分析

文中采用有限元法分析了大型离心压缩机叶轮焊接引起的出口流道变形规律和影响因素。研究结果表明,叶轮焊接及热处理后出口流道的变形主要是由盖盘变形引起的,流道出口高度的最终变形在2.3 mm左右。焊接后流道出口高度变形过大,于是设计了加装限位块以优化出口流道变形的方案。通过对限位块的不同位置分布进行数值模拟分析,结果表明限位块增设在叶片钝角侧后出口流道高度的焊接变形量降至原来的50%左右,叶轮总体变形振幅下降。     

大型鼓风机叶轮防变形焊接

分析了大型鼓风机叶轮的焊接变形。针对其变形规律制定了防止焊接变形的工艺措施:采用万向转胎;采用间歇性断续焊;减少熔敷金属量。通过这些措施,使叶轮的焊接变形量     

Ti-5Al-2.5SnELI合金扩散焊焊接质量的控制

总结了扩散焊基本工艺参数包括温度、压力、时间等对Ti-5Al-2.5SnELI钛合金扩散焊性能和焊接变形的影响.通过选择合适的工艺路线,控制以上工艺参数,并控制焊接变形改善钛合金低温叶轮的焊接质量.采用真空热压(HPV)+热等静压(HIP)工艺路线进行扩散焊接,可获得焊接强度大于710 MPa,焊接变形小于1%的叶轮零件.     

钛风机叶轮的研制

分析了焊制耐蚀钛风机叶轮的工艺特点.制定了合理的工艺参数,采取控制母材和焊丝中氧、氢、氮等杂质含量,彻底清除焊接部位及焊丝表面的氧化物、油污等措施,有效地解决了叶轮焊接过程中的污染问题.钛的弹性模量比钢小一倍,在焊接时产生较大的应力和变形.由于钛叶轮的焊接大多是丁字形焊缝,采用刚性固定法比较适合.焊后的叶轮与夹具一同送进炉内进行热处理,使焊制的风机叶轮变形程度降到最低点,从而提高了叶轮的尺寸、装配精度,延长了风机的使用寿命.     

贫液泵叶轮的焊接修复

介绍了贫液泵叶轮因设计上的问题，在运行后出现损坏的情况，通过对产生裂纹原因的分析，制定了合理的焊接工艺，采取适当的工艺措施控制焊接变形及应力，获得了满意的修复效果。     

M5—36型系列排粉风机叶轮焊接工艺及防变形措施的制定

本文主要介绍了风机的关键部件—叶轮制造中的焊接工艺及防变形措施。     

高温应用氦气压缩机窄流道叶轮焊接工艺开发及应用

叶轮是压缩机的核心部件,其制造质量和可靠性对机组的安全运行至关重要。文中简要介绍了高温应用氦气压缩机叶轮结构,分析了焊接难点,通过焊接工艺试验及焊接工艺评定说明了开槽焊工艺的可行性,并介绍了窄流道叶轮产品的焊接工艺。产品叶轮超转速及机械运转试验表明,叶轮开槽焊接接头的力学性能指标及加工质量满足设计要求。     

大型转轮不锈钢叶片焊接特点和焊接变形控制

对大型转轮不锈钢叶片焊接的特点和焊接变形，裂纹等问题进行了探讨，并通过采用合理的焊接工艺及防止和减少焊接变形的措施，达到控制焊接变形的目的，保证了轮转叶片的焊接质量。     

机车车辆大型长直弦梁焊接变形预测

基于MSC.Marc通用有限元软件平台开发高效的增强移动热源模型，并采用热-弹-塑性有限元法和增强移动热源模型，对长度为13 832 mm的机车车辆大型长直结构焊接变形进行了数值模拟.同时测量了长直结构的焊接变形，并与数值模拟结果进行比较，验证了所开发的有限元计算模型对长直结构焊接变形的准确性与可行性，随后，采用所开发的计算方法分析了不同焊接顺序对机车车辆大型长直结构焊接变形的影响.结果表明，焊接顺序对焊接变形的模态和大小均有显著影响，通过调整焊接顺序能够大幅减小焊接变形，试验结果指导了大型长直结构的实际生产，并且缩短了工艺开发周期.     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

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。     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

THERMODYNAMICS STUDY ON THE DECOMPOSITION OF CHROMITE WITH KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

INFLUENCE OF HEAT TREATMENT ON DAMPING BEHAVIOUR OF THE MAGNESIUM WROUGHT ALLOY AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

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.     

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X(X=Cr,Ta,Mo,Nb,Zr) Multilayer Films Adherent to Polyimide Substrates

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.     

High-Speed Friction Stir Welding of SiC_p/Al–Mg–Si–Cu Composite

A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.