大气等离子喷涂、HVOF和激光重熔法制备涂层的腐蚀性能

人们对可承受极端环境的高质量涂层的追求是无止境的。此类涂层应用范围广,从食品生产、制药工业设备到海上和电厂等更恶劣环境上都有涉及,使得产品零部件使用寿命延长,停机时间减少,产品组件材料更换的可能性降到最低。通常只有需要同时兼顾几种材料性能,这样才可以创造一种新的材料。这也意味着工业界关注几种涂层处理方法所能提供的涂层性能。本文将针对三种不同的工艺探究其可能性,它们分别是大气等离子喷涂(APS),高速火焰喷涂(HVOF),激光熔覆。选用钴基和镍基涂层材料为研究对象。在一定程度上选用碳化钨,氧化铬及一种封孔涂层进行对照分析。利用标准电化学设备来直接分析不同工艺及相应涂层的腐蚀特性,并进一步利用光学显微镜(LOM)、扫描电子显微镜(SEM)来解释和支撑电化学测试结果。     

HVOF喷涂Cr3C2-NiCr涂层：粉末颗粒形貌和喷涂参数对涂层微观组织、性能和高温耐磨性的影响

热喷涂碳化铬涂层广泛应用于高温耐磨环境。在这样高温的恶劣环境下,许多相会产生分解、氧化以及涂层组织变化,从而影响其耐磨性。尽管可以认为Cr3C2-NiCr涂层在高温条件下的组织分解将取决于喷涂微观结构和喷涂参数,但在这方面的研究较少。本文旨在设计出更好的喷涂参数,以提高碳化铬涂层在高温滑动磨擦磨损条件下的显微结构性能。通过X-射线衍射（XRD）和扫描电子显微镜（SEM）观察两种Cr3C2-NiCr相所形成的涂层组织,并且观察飞行颗粒的温度和速度。本文研究了800％下滑动摩擦行为与喷涂参数和涂层微观结构的关系,同时测量涂层在滑动磨擦前后的维氏硬度（300gf）。     

金厂金矿伽玛能谱测量和地电化参数法找矿预测应用研究

结合地质观察、首趺运用伽玛能谱测量法和地电化学参数法在金厂金矿外围及探部进行的找矿预测应用铡量表明、这2种方法具有简便、快速、宴用的特点。对谈类金矿床完全可以提供有效的找矿预测数据信息,圈定有利的矿化区(带)乃至隐伏矿体。     

高真空脉冲激光沉积CeO2（111）/Si（111）薄膜的结构与形貌研究

在高真空条件下,采用脉冲激光沉积法在Si(111)衬底上制备了高度(111)取向的CeO2薄膜。使用反射高能电子衍射仪对薄膜制备过程进行了原位监测,衍射花样为清晰条纹状,显示薄膜结晶质量较好,表面平整光滑。采用X射线衍射仪对不同衬底温度、不同激光能量制备的薄膜进行了结构表征,随着温度升高和能量增强,CeO2薄膜(111)峰逐渐增强且峰位越来越靠近标准峰位,表明CeO2薄膜的取向性变好且薄膜应力逐渐下降。通过椭偏仪对薄膜的折射率进行了表征,结果表明薄膜的光学性能强烈依赖其结晶质量,结晶质量最好的样品折射率接近单晶薄膜。使用高分辨透射电镜表征了样品的横断面,照片显示薄膜内部原子排列有序,结晶质量较好,部分区域与衬底取向略有偏差。     

硫酸钠复盐法分离Ce（Ⅳ）和RE（Ⅲ）过程中影响分离效果的因素的研究

在硫酸稀土溶液中，用Ｎａ２ＳＯ４复盐法分离Ｃｅ（Ⅳ）和ＲＥ（Ⅲ）时，研究了溶液中Ｆ－浓度、Ｎａ２ＳＯ４加入量、反应时间、温度和溶液的酸度对Ｃｅ（Ⅳ）提取率的影响，以及复盐沉淀洗涤情况对Ｃｅ（Ⅳ）和ＲＥ（Ⅲ）分离效果的影响。确立了在稀土溶液中用Ｎａ２ＳＯ４复盐法提取铈和少铈稀土的合理工艺条件。     

SART法和配合沉淀法脱除氰化贫液中铜氰的对比研究

针对某黄金生产企业铜硫分离浮选后硫精矿氰化产生的氰化贫液,分别采用SART法与配合沉淀法净化处理,对比研究了2种方法的铜与氰化物的脱除效果及回收沉渣中铜、金的经济效益。结果表明：贫液中铜、金、氰化物和硫氰酸盐质量浓度分别为121.46、0.12、150.84、252.65 mg/L时,采用SART法时在溶液pH=5、硫铜物质的量比2∶1条件下,滤液中铜、总氰化物质量浓度为1.52、99.72 mg/L,沉渣中铜、金质量分数分别为65.26%、10.56 g/t;采用配合沉淀法时,在铜离子与亚硫酸根物质的量比1.25∶1、铜离子与氰化物与硫氰酸盐之和物质的量比2∶1条件下,滤液中铜、总氰化物质量浓度为22.08、0.77 mg/L,沉渣中铜、金质量分数分别为51.26%、86.53 g/t;相较SART法,配合沉淀法回收有价金属经济效益更高,更适于回收含铜氰化贫液中的铜和氰化物。     

国外热喷涂技术的进展

本文介绍了气体火焰喷涂、电弧喷涂、等离子喷涂,以及新出现的爆炸喷涂和激光喷涂的技术,及其发展概况、应用领域等。     

Transient Fluid Flow in a Continuous Casting Tundish during Ladle Change and Steady‐state Casting

Transient effects occur during both steady‐state casting as well as transient casting, e.g. a ladle change. These effects are caused by transient boundary conditions at the inlet of the tundish. A time‐dependent inlet temperature causes a free convection flow during steady‐state casting. During transient casting, such as during a ladle change, the mass flow at the inlet is time‐dependent and thus a transient flow develops. In general, transient flow is unwanted because transient flow means a change of conditions for the separation of non‐metallic particles. The analysis of the flow in the tundish is carried out by numerical as well as physical simulations. In this case experimental investigations are carried out on a water model. The results of laser optical investigations using Laser Doppler Anemometry (LDA) and Particle Image Velocimetry (DPIV) serve as a validation of the numerical results. The numerical results are then used for the investigation of the thermal melt flow. The effects caused by a changing bath level during transient casting (ladle change) are investigated using the Volume‐of‐Fluid (VoF) model. Beyond this, the interaction between the melt and slag is taken into account, by using the three phase system melt‐slag‐air. In addition to the classical methods a new zonal approach is introduced in this paper. The integral balance localises high turbulence mixing regions as well as the development and intensity of back flows. The levelling of the momentum flux between the inlet and the outlet can also be described.     

Selection of Strategies for Winter Maintenance of Roads Based on Climatic Parameters

The aims of the presentation are to discuss the efficiency of the different methods for friction control of winter roads on the safety and accessibility due to climatic conditions, to show that the climate should be an important factor in selecting the strategies for winter maintenance and to establish climatic parameters that may be helpful in making those decisions. The analyses are based on Swedish data assembled by VTI on road accidents involving fatalities and severe injuries, road surface conditions and climate. The accident and the road condition recordings are compared to self-defined climatic parameters, which describe the severity, stability and instability of the winter climate in the regions investigated. The parameters are assumed to describe whether salting or sanding is favorable/unfavorable for friction control. The results of the analyses show that the effect of salting is substantial for improving accessibility. Generally the number of winter accidents resulting in fatalities and severe injuries is lower on the salted road network compared to the unsalted road network in the southern and central parts of Sweden. However, in the northern region, with very cold winters, the number of winter accidents is highest on the salted road network. The data also indicates that the highest accident numbers are found when the proportion of vehicle mileage on snow and ice in the winters varies within 30–40%. The paper recommends that salting should be avoided in areas and in periods when the frequency of road surface temperatures below ?8°C exceeds 20%. In such climates the warm-wetted sand method is probably more favorable for friction control. Warm-wetted sand is also favorable on roads with traffic less than average annual daily traffic 2,000 and in periods with stable winter conditions.     

高炉煤气洗涤塔喷淋系统的改造

介绍厂攀钢动力厂某高炉煤气洗涤塔喷淋系统存在的问题，提出了改造措施，达到了确保煤气清洗质量和节约水资源的效果。     

Simplified Relationships for Particle-Size Distribution and Permeation Groutability Limits for Soils

The particle-size distribution of soil with mean particle size and fines content are used not only in soil classifications but also in a number of other soil property relationships. In this study, two simple relationships (hyperbolic [tan?h(x)] and S-curve) were investigated to represent the particle size distribution of soils. The parameters of the hyperbolic model were correlated to various soil parameters such as the mean particle size, particle size range, and fines content. There was no direct correlation between Fredlund (four-parameter model) and S-curve model parameters and the soil parameters. The predictions of the two (hyperbolic) and three (S-curve) parameter models were compared to the four-parameter model (unimodal) using limited soil data from the literature and the agreements were good. The hyperbolic model was used to map the Unified Soil Classification System. A recent study had quantified the relationship between the grouting pressure and the fines content in nonplastic soils. Also in the current practice, upper and lower particle-size distribution limits are used in determining the groutability of soils. In this study, the relationship between grouting pressure and fines contents of the soil was generalized using the hyperbolic particle-size distribution model and verified with a groutability study using an acrylamide grout. Based on limited data in the literature, the groutability of soils was defined using a new set of parameters, grouting pressure, fines content, and mean particle size diameter of the soil.     

酸轧联合机组焊机选型探讨

介绍冷轧带钢系统酸轧联合机组带钢焊机的种类和工作原理，对比分析闪光焊机和激光焊机的性能和设备特点，提出焊机选型建议。     

Graphical and statistical comparison of various size distribution measurement systems using metal powders of a range of sizes and shapes

Abstract

The purpose of this paper was to describe the results of particle size analysis from image analysis, sieving analysis and dry or wet dispersion laser diffraction and compare these techniques. Measurements were made on particle systems of different morphological characteristics, size and particle size distribution widths using the most common metal powders. The results show reasonably good agreement between the different techniques concerning the shape of the distribution. However, there is a discrepancy regarding the absolute values, which can be explained by the fact that the techniques used are based on different measuring principles. The study suggests that image analysis is a powerful tool in characterising non-spherical particles, especially elongated particles and that caution needs to be taken when evaluating the sizing results of non-spherical particles using laser diffraction.     

喷雾推进冷却塔在炼钢氧枪冷却水系统的应用

介绍了喷雾推进通风冷却塔在济钢一炼钢厂氧枪冷却水循环系统中的应用。运行情况表明:较之传统的机械通风冷却塔,喷雾塔具有冷却效果好,节能效益显著,一次性投资省,运行维护可靠方便的优点。该塔在同类型企业中具有广泛的应用前景。     

基于粒子系统的静电喷涂雾化模拟研究

介绍了静电喷涂的整个过程 ,探讨了如何运用粒子系统模拟静电喷涂中油液的雾化情况 ,并运用此方法建立了静电涂油机喷涂时油液雾化的仿真模型 ,最后实现了雾化过程的动态模拟 ,为以后此方面的仿真研究提供了一种新思路。     

氯化物对烧结矿RDI影响的试验研究

介绍了在烧结矿表面喷洒ＣａＣｌ２等稀溶液以降低宝钢烧结矿ＲＤＩ指数的实验室试验研究，以及在烧结混合料中添加少量ＣａＣｌ２烧结的试验研究结果。