HTPB/AP复合推进剂装药直径对冲击波点火的影响

为研究HTPB／AP复合推进剂装药直径对冲击波点火的影响作用,用隔板实验测试了不同装药直径对冲击波点火临界燃烧厚度及峰值压力的影响。确定了最佳药柱直径,并对其点火可靠性及药柱受冲击波点火后密度变化进行测试。结果表明,药柱直径与临界燃烧隔板厚度及冲击波强度有着密切的关系。密度为1．563g／cm^3时,HTPB／AP复合推进剂的最佳冲击波点火推进剂装药直径为40mm,且冲击波点火可靠性良好,药柱受冲击波作用后,密度发生一定变化。     

弹丸侵彻塑料帽物理过程及其阻力特性

介绍一种新型无壳枪弹装药结构，即埋头无壳枪弹，其特征是金属弹丸完全被包容在药柱内，并用一枚塑料帽密封。文中给出了在弹道起始过程中有关弹丸侵彻塑料帽的物理过程模型，为设计埋头无壳枪弹所用塑料帽的结构尺寸提出了理论依据。     

弹丸侵乇塑料帽物理过程及其阻力特性

介绍一种新型无壳枪弹装药结构，即埋头无壳枪弹，其特征是金属弹丸完全被包容在药柱内，并用一枚塑料帽密封。文中给出了在弹道起始过程中有关弹丸侵乇塑料帽的物理过程模型，为设计埋头无壳枪弹所用塑料帽的结构尺寸提出了理论依据。     

分散药T型装药控制二次引爆型FAE云雾研究

为了控制新型FAE弹体云雾的窜火、形状、直径与高度等,设计出直径不同的两种药柱间隔装填的分散药T型装药结构,着重对两种药柱的半径、高度、爆速、密度、分散药燃料比进行了设计。在假设小药柱以平面爆轰波引爆大药柱的前提下,对大药柱爆轰波正常传播条件进行了理论推导。选择宏观固态燃料,对Φ330mm×430mm的新型FAE炸弹进行静爆实验;运用柯达高速运动系统观测云雾形成及爆轰过程,并对FAE云雾的直径、高度和体积进行了处理和分析。结果表明,分散药T型装药能有效地控制FAE云雾的形状、直径、高度以及云雾体积,特别是对遏制云雾窜火有很好的效果。     

含AP炸药装药在剪切加载下的动态响应特性

采用小落锤加载装置和自行设计的剪切装置研究了含AP及不含AP的两种炸药装药在剪切加载下的动态响应特性,分别采用高速摄影和扫描电镜记录了装药动态响应过程和晶体的微观状态。结果表明,含AP炸药装药的临界点火阈值为1.0m,不含AP炸药装药的临界点火阈值为1.2m,表明AP的加入使整个炸药装药变得敏感;炸药药柱在加载作用下主要经历冲击、塑性流动、剪切、飞散、反应等阶段;剪切加载后的AP晶体损伤以剪切变形和穿晶断裂为主,而RDX晶体以塑性变形和破碎为主,差异主要与AP晶体的力学强度较低及没有明确的熔点性能有关。     

浅谈柴油机油发展对腐蚀性能影响及对策

通过对腐蚀问题产生的原因及评价方法介绍,说明柴油机油腐蚀性能的重要性;同时对发动机新技术采用、柴油机油规格提升、代用燃料应用等对油品腐蚀性能的影响进行详细分析,指出柴油机油发展使油品腐蚀性能的矛盾日益突出。另外通过对金属减活剂、某些清净剂和新型添加剂等资料总结,给出了解决现代柴油机油腐蚀问题的方案。     

浅谈柴油机油发展对腐蚀性能影响及对策

通过对腐蚀问题产生的原因及评价方法介绍,说明柴油机油腐蚀性能的重要性;同时对发动机新技术采用、柴油机油规格提升、代用燃料应用等对油品腐蚀性能的影响进行详细分析,指出柴油机油发展使油品腐蚀性能的矛盾日益突出。另外通过对金属减活剂、某些清净剂和新型添加剂等资料总结,给出了解决现代柴油机油腐蚀问题的方案。     

化工防腐蚀基本知识介绍(一)

绪论一、腐蚀和防腐蚀的重要性: 通常说的金属生锈就是腐蚀,金属在酸中溶解也是腐蚀。腐蚀现象在日常生活中随时可见,当然也存在国民经济的各个部门,所以材料的腐蚀是一切工业,特别是化学工业中一个非常重要的问题。因为在石油化工生产中,生产设备常和強腐蚀性介质如酸、碱、盐和腐蚀性气体接触,加之有不少化工生产过程是在高温、高压、高流速以及深冷条件下进行,对设备产生严重的腐蚀,因而正确而合理地选择化工机械设备的材料,采用必要的防腐措施,是一个十分重要的问题。     

温度循环载荷作用下压装A-IX-II装药的裂纹机理研究

为了研究压装A-IX-II炸药装药对环境温度的适应性,通过-54~71、-15~71、-54~60、-54~55℃四个温度范围的高低温循环试验研究了1.65、1.70、1.75g/cm3三种装药密度和Φ60mm×60mm、Φ40mm×40mm两种尺寸的A-IX-II炸药药柱裂纹产生的规律,讨论了高低温循环试验中A-IX-II炸药药柱裂纹形成的机理。通过裂纹出现的位置、钝感剂性质和加载温度范围分析了导致A-IX-II炸药药柱产生裂纹的原因。结果表明,在温度循环载荷下高密度和大尺寸药柱更容易产生裂纹。导致A-IX-II炸药药柱产生裂纹的可能原因有两种:一是在老化过程中钝感剂石蜡/硬脂酸体系液化和局部流失使药柱的结构强度下降;二是热胀冷缩形变产生的应力使药柱结构完整性最终被破坏;同时,基于这两种因素解释了药柱密度和尺寸对裂纹产生的影响。     

缓蚀剂在金属防腐技术中的应用

金属材料在绝大数情况下与腐蚀性环境介质接触会发生腐蚀,研究金属防腐技术是迫切需要解决的问题。缓蚀剂保护是一种通过添加少量能阻止或减缓金属腐蚀的物质使金属得到保护的方法,文章介绍了缓蚀剂的定义及技术特点,以及缓蚀剂在金属防腐技术中的应用。     

封闭处理对建筑结构钢锌系磷酸盐转化膜性能的影响

以建筑结构钢作基体制备锌系磷酸盐转化膜,并采用不同类型封闭液对磷酸盐转化膜进行封闭处理,研究了封闭处理对磷酸盐转化膜的微观形貌、表面成分、厚度和耐蚀性能的影响。结果表明：封闭处理对磷酸盐转化膜的宏观形貌和厚度没有显著性影响,但是微观形貌、表面成分和耐蚀性能存在差异。未封闭及封闭处理后磷酸盐转化膜的表面成分都以锌、氧和磷元素为主,封闭处理后磷酸盐转化膜表面趋于平整、致密性改善、耐蚀性能明显提高,主要归因于不同类型封闭液都起到填补晶粒间缝隙的作用,阻止腐蚀介质向磷酸盐转化膜内部渗透。采用硅酸钠和硝酸铈配成的封闭液封闭处理后的磷酸盐转化膜表面更加平整致密,其溶液电阻和电荷转移电阻均最大,分别达到58.2、4.02×10³ Ω·cm ²,且具有最大的相位角和最宽的频率范围。该磷酸盐转化膜的耐蚀性能更好,腐蚀耐久性也较理想,具有应用潜力,有望用作建筑结构钢表面防护层。     

Electrochemical behaviour of copper/LDPE composites in the simulated uterine solution

Two metal/insulator composites, copper/low-density polyethylene (LDPE) microcomposites and copper/LDPE nanocomposites, were prepared in a uniform metal mass fraction. The corrosion characteristics of the two composites in the simulated uterine solution have been studied by cyclic voltammetry, potentiodynamic polarization measurement and electrochemical impedance spectroscopy. Results obtained during this study show that there are obvious differences on the corrosive rates and mechanisms between the two materials. The nanocomposites have stable corrosive reaction, hardly passivation, low corrosion rate and high transformation ratio of copper to soluble cupric ions compared with microcomposites, which indicate that the nanocomposites are perfect to be the novel material for intrauterine device. The corrosion behaviour of the microcomposites was controlled by both the processes of the pervasion of Cu²⁺ and the transfer of the charge, while that of the nanocomposites was only controlled by the transfer of the charge. This paper also compared the corrosion behaviours of the composites and bulk copper in the simulated uterine solution, there were more insoluble subproducts in the corrosion process of bulk copper than the composites. Further, the electrochemical method in this study is proved to be useful to characterize the corrosion behaviour of high electrical resistivity materials.     

Theoretical challenges in understanding the inhibition mechanism of aluminum corrosion in basic media in the presence of some p-phenol derivatives

Using quantum electrochemical/thermodynamical approaches based on coupled cluster/polarized continuum models and density functional theory (CM/PCM–DFT), we investigated the corrosion inhibition mechanism of Al/NaOH system in the presence of some p-phenol derivatives. The influencing parameters on inhibitory action, i.e. charges on oxygen and hydrogen atoms of hydroxyl group, charge transfer, interaction energy, molecular activity and softness, electric dipole moment and de-solvation free energy, were determined for both neutral and deprotonated species at metal|solution interface. A good correlation was observed between these parameters and inhibition efficiency data reported in the literature. By introducing an appropriate thermodynamic procedure, we also determined the proton-loss tendency of the molecules nearby interface. The results were amazing and revealed a complicated protonation/deprotonation cycle for inhibitor species inside electrical double layer; the corrosive agents in the vicinity of metal surface become locally neutralized and pushed away.     

The influence of aluminium surface pretreatment on the corrosion stability and adhesion of powder polyester coating

One of the most important factors in corrosion prevention by protective coatings is the coating adhesion loss under environmental influence. Thus, adhesion strength is often used when characterizing protective properties of organic coatings on a metal substrate. In order to improve the adhesion of organic coating the metal substrate is often pretreated in some way. In this work, the adhesion of polyester coatings on differently pretreated aluminium surface (by anodizing, with and without sealing, by phosphating and by silane film deposition) was examined. The dry and wet adhesion of polyester coatings were measured by a direct pull-off standardized procedure, as well as indirectly by NMP test. It was shown that under dry test conditions all polyester coatings showed very good adhesion, but that aluminium surface pretreated by silane film showed superior adhesion. The overall increase of wet adhesion for polyester coating on aluminium pretreated by silane film was maintained throughout the whole investigated time period. The different trends in the change of adhesion of polyester coatings were observed for different aluminium pretreatments during exposure to the corrosive agent (3% NaCl solution). The highest adhesion reduction was obtained for polyester coating on aluminium pretreated with phosphate coating. The corrosion stability of polyester coated aluminium was investigated by electrochemical impedance spectroscopy in 3% NaCl solution. The results confirmed good protective properties of polyester coating on aluminium pretreated with silane film, i.e. greater values of pore resistance and smaller values of coating capacitance were obtained in respect to other protective systems, whereas charge-transfer resistance and double-layer capacitance were not measurable during 2 months of exposure to a corrosive agent.     

防治金属腐蚀的五大对策

本文从理论和应用上概括介绍了防治金属腐蚀的五大对策，即隔离法，增大电极电势法，阴极保护法，改善腐蚀环境和介质（缓蚀剂法），以及研制开发新的耐腐蚀材料等。     

A model for the corrosion of steel subjected to synthetic produced water containing sulfate, chloride and hydrogen sulfide

A model was developed for the prediction of corrosion rates associated with steel subjected to synthetic produced water. The corrosive species included in the model, identified through water analysis conducted in the field, are sulfate, chloride and hydrogen sulfide. The effect on corrosion of these species was examined through polarization experimentation using a three electrode glass corrosion cell and potentiostat. Samples of carbon steel, used in sub-sea pipeline systems, were used at the working electrode and the experiments were carried out at similar physicochemical conditions observed in pipeline systems in the field. The model was based on heterogeneous reactions at the metal surface, with electrochemical parameters determined through experimentation employed in the model to describe the anodic and cathodic processes involved in the corrosion of steel. The model consists of a system of equations with Butler–Volmer kinetics describing the charge transfer and the Nernst diffusion model the mass transfer processes occurring in the corrosion system. The solution is based on a charge balance between the reduction and the oxidation processes which occur at the steel surface. Current density convergence criteria were used in the model to solve the system of equations for corrosion potential, surface species concentration and component current densities. The corrosion rate is determined as the rate of oxidation of iron at the surface and model results have been validated using experimental data. The model demonstrates a reasonable qualitative match with corrosion data collected in the potential region close to the corrosion potential in general, with good qualitative match in the anodic region near the corrosion potential. Some deviation occurs between model and experimental values where overpotentials become large but the model is shown to respond well to changes in input parameter values and predicts the corrosion potential and corrosion rate for each system within experimental variability and the accepted standards of accuracy.     

变电站接地网腐蚀行为的实验室快速测定

根据变电站接地网腐蚀行为的研究现状,在实验室建立了一个模拟金属土壤腐蚀行为的装置。工作中以A3铜为测试金属,以嘉兴地区两个110kV变电站的土壤为目标土样,利用试片失重法和电化学测试技术对模拟装置的有效性进行了评价。结果表明,在电化学活化控制条件下,所建的土壤模拟腐蚀装置能有效地反应变电站现场A3钢的腐蚀情况,两者的实验误差在20％以内。以上研究成果对指导接地网运行具有重要的意义。     

复合型缓蚀剂的缓蚀性能

在考察引起空冷器腐蚀的主要参数,即腐蚀因子(Kp)的条件下,通过配制模拟腐蚀溶液,采用电阻探针腐蚀速率测试装置,在实验室条件下,研究了有机缓蚀剂苯并三唑及其复合物的缓蚀性能。结果表明:缓蚀剂苯并三唑及其复合物之间具有良好的协同缓蚀作用,有效地降低了金属表面的腐蚀速率。     

Experimental investigation of high-temperature corrosion properties in simulated reducing-sulphidizing atmospheres of the waterwall fireside in the boiler

The presence of reducing atmospheres of the waterwall fireside in the boiler due to extensive use of low-NOx combustion mode caused severe high-temperature corrosion problems. In this study, high-temperature sulphur corrosion properties of two types of low alloyed waterwall steel (15CrMoG and 12Cr1MoVG) in two kinds of reducing-sulphidizing atmospheres were investigated by lab-scale experiments. The experimental atmospheres and temperature were simulated according to field measurements in the boiler of a thermal power plant. The experimental results showed that the reducing-sulphidizing atmosphere with CO was more corrosive, and the CO accelerated the corrosion of H₂S and worsened the corrosion. The CO inhibited the formation of oxide scales, provided some corrosion resistance, and produced the intensely corrosive COS. The corrosivity of the alkali metal chlorides was limited in the reducing-sulphidizing atmosphere without CO, while the corrosion was strongly hindered in the reducing-sulphidizing atmosphere with CO.