高强焊条药皮碱度对韧性与扩散氢的影响

通过使用钛硼微合金化以获得韧性组织焊缝、提高焊条药皮碱度以净化焊缝等手段,可使屈服强度级别为785MPa的手工焊条熔敷金属-50℃冲击吸收功AKV平均值超过80J.但焊条药皮碱度过高时,AKV(-50℃)值没有明显增加,而且对降低熔敷金属扩散氢不利.采用对焊条药皮原材料进行分类高温去水处理,对成品焊条多次烘干吸湿烘干处理后,反复测定.结果表明,当焊条药皮碱度在2.2～2.4之间时,熔敷金属可同时具有高屈服强度、高低温冲击吸收功及超低扩散氢.     

焊接材料及其生产设备

铁基高碳耐磨堆焊焊条性能研究;高效高硬度低成本耐磨堆焊焊条的研制;新渣系碱性焊条脱渣性分析;高强焊条药皮碱度对韧性与扩散氢的影响;镍基合金药芯焊丝熔敷金属耐腐蚀性能的研究;     

焊接材料及其生产设备

铁基高碳耐磨堆焊焊条性能研究;高效高硬度低成本耐磨堆焊焊条的研制;新渣系碱性焊条脱渣性分析;高强焊条药皮碱度对韧性与扩散氢的影响;镍基合金药芯焊丝熔敷金属耐腐蚀性能的研究;     

手工电弧焊中磷在熔渣-熔敷金属两相间的分布

通过试验和理论分析，研究了手工电弧焊磷在熔渣和熔敷金属中的分配比。结果表明，焊条药皮的碱度或熔渣中提高，使Ｌｐ增加；虽然在改变焊条药皮组成和渣中ＦｅＯ量的情况下，焊缝金属的脱磷是有限的，但合适的药皮碱度和熔渣ＦｅＯ含量，焊缝金属还是可以获得较好的脱磷效果的。     

稀土低合金耐磨钢堆焊焊条熔敷层性能研究

通过扫描电镜、能谱分析、磨损试验系统地研究了熔敷层金属化学成分、耐磨性、冲击断口形貌.试验结果表明,同等条件下,焊条药皮中添加稀土氧化物可以提高熔敷层耐磨性能;药皮配方中添加质量分数为1.5%的氧化铈的耐磨性强于添加1.5%的氧化钇的耐磨性.     

挖掘机斗齿高锰钢堆焊材料的研究

针对高锰钢堆焊材料工艺性的不足,采用药皮过渡合金元素的方法,通过正交试验对配方进行优化设计,试制了一种高锰钢堆焊焊条.通过化学成分分析、抗热裂试验、静载及动载加工硬化试验和摩擦磨损试验,评价了焊条的工艺性能和使用性能.结果表明:焊条熔渣活度大,熔点较低,熔敷金属成分与母材接近;焊条熔敷金属的抗热裂性能良好,加工硬化效果显著,耐磨性优于母材.     

大型工件的粗焊条补焊

大型工件的修复焊接,可采用焊芯直径达19毫米的焊条进行补焊。这种焊条的熔敷率可达40公斤/小时,在美国得到广泛地应用,英国也开始采用。该焊条药皮很厚,可以在很宽的范围内调整熔敷金属的化学成分,熔敷金属的硬度为RC15～40。商品焊条的直径为2.4～19     

双相不锈钢焊条的研制

介绍了双相不锈钢焊条ＡＦ３１０的研制过程，分析了焊条药皮渣系、熔敷金属合金元素对该焊条性能的影响，确定了合理的药皮配方，所研制的双相不锈钢焊条ＡＦ３１０工艺性能良好，熔敷金属机械性能达到或接近国外同类产品水平。     

焊条中Mn、Si过渡的CAD方法

在收集大量焊条药皮的试验配方和相应的焊接熔敷金属化学成分的基础上,采用多元回归分析的方法对焊条中合金元素Mn和Si的过渡进行统计分析研究,采用Visual Basic成功地编制了焊条中元素Mn、Si过渡到焊接熔敷金属的数学建模软件,并建立了焊条中元素Mn、Si过渡的经验公式。通过自制焊条的试验和分析结果表明,本文所建立的焊条中元素Mn、Si过渡的经验公式对普通焊条药皮配方的设计有重要的指导意义。初步试验也证明了这一软件是有效的焊条配方CAD设计方法。     

结构钢焊条熔敷金属化学成分的人工神经网络预测系统

基于Matlab神经网络工具箱，设计了一个用于结构钢焊条熔敷金属化学成分预测的神经网络模型。该模型采用前向神经网络，利用BP算法，建立了熔敷金属化学成分与力学性能之间的关系。用此神经网络，既可预测结构钢焊条熔敷金属化学成分，也为深入研究结构钢焊条化学成分提供了有利的工具。     

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.