Al对含P,Mo奥氏体不锈钢应力腐蚀性能的影响

用点焊接试验方法评价了合金元素Ａｌ对含Ｐ和Ｍｏ奥氏体不锈钢应力腐蚀破裂性能的影响。结果表明，单独添加Ａｌ没有改善应力腐蚀破裂性能，而复合添加Ａｌ和Ｃｕ有效地提高了抗应力腐蚀性能。１４Ｃｒ－１６Ｎｉ－２Ｃｕ－３Ａｌ钢中添加Ｍｏ，虽然降低应力腐蚀性能，但影响较小。含０．３％Ｍｏ时应力腐蚀破裂临界温度可达１２０℃。ＡＥＳ分析表明，Ａｌ和Ｃｕ元素在表面膜中富集。Ａｌ和ｃｕ的联合作用使钢表面膜的钝化能力得到加强，从而提高了抗应力腐蚀性能。     

X70管线钢在湿H_2S环境中的应力腐蚀行为研究

运用均匀设计方法,通过改变H2S浓度、Cl-浓度、pH值和温度等溶液介质参数,对X70管线钢在湿H2S环境中进行慢应变速率拉伸应力腐蚀试验.研究各参数对X70管线钢应力腐蚀开裂的影响规律,通过扫描电镜分析试样断口的微观形貌,确定其应力腐蚀敏感性,并根据试验结果计算在各试验环境下的应力腐蚀敏感性指数,运用回归分析软件,建立X70管线钢应力腐蚀敏感指数与试验介质参数之间关系的交互型数学模型.     

pH值对7050铝合金膜致应力和应力腐蚀敏感性的影响

采用慢应变速率拉伸法和流变应力差值法研究了7050铝合金在3.5%(质量分数)NaCl水溶液中膜致应力和应力腐蚀敏感性随pH值的变化规律。结果表明:当pH≤7时,随着pH值的增大,膜致应力和应力腐蚀敏感性均下降,当pH7时,膜致应力和应力腐蚀敏感性随着pH值的增大而提高;而当pH=1,14时,腐蚀的类型为剥蚀,合金基体发生剥落,表面没有钝化膜产生。pH值在6~9之间时,膜致应力随pH的变化比较平缓,而pH在2~5和10~13之间时,膜致应力变化则较为剧烈,整体的变化曲线呈山谷形。膜致应力和应力腐蚀敏感性具有很强的相关性。XPS研究表明,膜致应力值与钝化膜的成分有关。     

硫化物应力腐蚀裂开时硫化氢极限浓度的研究

用慢应变速率应力腐蚀试验机研究了含硫天然气输气管道用钢在5%氯化钠溶液中的硫化物应力腐蚀裂开(SSCC) 敏感性与硫化氢浓度之间的关系.本文报导了20号钢和16锰钢在上述介质中发生SSCC的硫化氢极限浓度,为工程设计和生产过程的安全保障提供了重要的参数.     

低合金结构钢强度等级对应力腐蚀的影响

研究了不同强度等级的低合金结构钢在不同温度的空气及介质中的拉伸性能。结果表明，温度不同，其应力腐蚀敏感性也不同。试验的３０Ｃｒ２Ｎｉ４ＭｏＶ钢，在２３０℃附近塑化明显下降，在３．５％ＮａＣｌ水溶液中会发生应力腐蚀，且在２３０℃时应力腐蚀敏感性最大（Ｉψ〉４０％），说明此为蓝脆与应力腐蚀交互作用的结果。该钢在８％ＮａＯＨ溶液中，应力腐蚀的敏感性则随温度的升高而升高（Ｉψ〉６５％）。     

喷丸,化学镀Ni—P对1Cr18Ni9Ti不锈钢抗应力腐蚀的影响

用三点加载试件研究了表面喷丸和化学镀Ｎｉ－Ｐ对１Ｃｒ１８Ｎｉ９Ｔｉ不锈钢在１５４℃，４０％ＭｇＣｌ２中的应力腐蚀敏感性的影响，两种表面处理都大大增强材料抗应力腐蚀破裂的能力。当外加应力不超过喷丸造成的应力时，喷丸对抗开裂非常有效；外加应力大于喷丸压应力后，随应力升高破裂时间缩短，化学镀Ｎｉ－Ｐ的保护效果主要决定于镀膜的完整性，在试件边棱处受力较苛刻部位，应力腐蚀最易产生，讨论了外加应力、膜的延性和     

拉伸变形对304不锈钢应力腐蚀的影响

研究了在-70℃和180℃拉伸变形对304不锈钢应力腐蚀的影响，结果表明，随着拉伸变形量的增加，180℃拉伸变形的304不锈钢在42％沸腾MgCl2溶液中应力腐蚀破裂敏感性逐渐减小，而在-70℃拉伸变形的304不锈钢在42％沸腾MgCl2溶液中应力腐蚀破裂敏感性经历了一个从减小到增大的过程．马氏体相的存在导致304不锈钢在42％沸腾MgCl2溶液中应力腐蚀破裂敏感性增大。     

7B04铝合金应力腐蚀敏感性研究

利用慢应变速率拉伸应力腐蚀实验方法研究7B04铝合金的应力腐蚀开裂敏感性。研究温度、腐蚀介质、电化学极化对应力腐蚀敏感性的影响,结果表明:随温度的升高7B04铝合金的应力腐蚀开裂敏感性增强;溶液的腐蚀性越强,7B04铝合金的应力腐蚀开裂敏感性越大;无论是阳极极化还是阴极极化都会增加7B04铝合金的应力腐蚀开裂敏感性。     

静水压力和阴极极化对钛合金应力腐蚀敏感性的影响

采用电化学极化实验、慢应变速率拉伸实验、断口形貌观察和恒变形应力腐蚀裂纹扩展实验的方法,研究静水压力和阴极极化对Ti75合金海水应力腐蚀的影响.结果表明:静水压力对Ti75合金的应力腐蚀敏感性没有明显影响.在阴极极化情况下,Ti75合金的应力腐蚀临界应力强度因子(KISCC)下降,其应力腐蚀敏感性随着电位的负移而提高,...     

316L不锈钢板式换热器泄漏原因

316L不锈钢板式换热器使用约半年后频繁出现泄漏事故,通过扫描电镜分析、能谱分析、金相检验、显微硬度检测和有限元模拟分析等方法对泄漏原因进行了分析.结果表明:316L不锈钢板片发生了应力腐蚀开裂,造成泄漏.板片冷加工后产生了较大的残余拉应力且环境中存在Cl-腐蚀介质,导致残余应力较大的波峰和波谷处产生裂纹和腐蚀坑,是造...     

空心微珠/环氧树脂高强浮力材料的性能及断裂分析

以环氧树脂为基体, 经硅烷活化处理的空心玻璃微珠(HGM)为填充剂, 制备了高强浮力材料。采用XRD、 FRIR分析了HGM的结构和硅烷处理效果, 通过密度测试和单轴静态压缩试验研究了HGM的类型和含量对浮力材料性能的影响, 利用SEM和吸水率试验研究了浮力材料的断裂特性和吸水性。结果表明: HGM为无定形结构; 硅烷分子接枝在HGM表面, 使得HGM与环氧树脂完好结合且两者界面没有间隙沟槽; HGM的较大比压缩强度有利于提高浮力材料的性能; 高强浮力材料密度为0.645~0.850 g/cm3, 抗压强度为60~93 MPa, 比压缩强度为92~112 MPa·cm3·g-1; HGM含量较少时, 浮力材料断裂表面HGM破裂处的基体环氧树脂有拖尾特征, HGM含量增多时, HGM的破坏程度不断增大直至完全破坏; 浮力材料具有较好的抗吸水性。      

空心玻璃微珠/硅橡胶基柔性浮力材料的制备与性能研究

以牌号为HGS8000X的空心玻璃微珠(HGM)为填料,以液体硅橡胶(SR)为基体,采用真空辅助浇铸法和模压法制备柔性浮力材料,并研究空心玻璃微珠体积分数对柔性浮力材料的密度、拉伸性能、硬度和吸水率的影响。结果表明,所制备的柔性浮力材料的密度为0.6~0.8 g/cm3,在40 MPa水静压下2 h吸水率最大不超过0.25%,是良好的深海用柔性浮力材料;随着空心玻璃微珠添加量的增加,柔性浮力材料的密度降低,吸水率增加,弹性降低,硬度提高。     

Thermal stability and decomposition kinetics of Li2Al4CO3(OH)12·3H2O

The thermal stability of lithium containing hydrotalcite, a material that has potential application for providing atmospheric corrosion protection to aluminium alloys, was investigated. Lithium aluminium carbonate hydroxide hydrate (Li₂Al₄CO₃(OH)₁₂·3H₂O) coatings were prepared by immersion of an 1100 aluminium alloy into a lithium carbonate-lithium hydroxide solution, and the bulk material was prepared by precipitation in the same solution. Thermal stability of the coatings and the bulk material existed to around 150 °C. Above this temperature, interlayer water was expelled, followed by loss of structural water and carbon dioxide. The kinetic parameters for interlayer water loss have been determined, and water loss can be described by a Johnson-Mehl-Avrami rate equation.     

Intercalation and Stability of Layered Semiconductive Material in Corrosive Environment

The intercalation of 4-methyl pyridine （4-picoline） into layered semiconductive material （MnPS3） and the stability of the resulting materials in corrosive environments （water, HCI and open atmosphere） were investigated. Powder X-ray diffraction （XRD） indicated that the presence of water and hydrochloric acid greatly influenced the existing form of intercalation and its orientation in the interlayer of the host. Atmospheric environment （open air） affected the guest orientation in the interlayer of the host material. Phase transformation occurred and the material was stable. The intercalated compounds could be indexed in the trigonal unit cell. The XRD patterns exhibited sharp hkl reflections of the intercalated compounds, which formed in water and HCI, confirming that the materials were well crystalline and stable in corrosive environments.     

水灰比对镁系无机轻质材料性能的影响规律

以镁系胶凝材料为主料,双氧水为发泡剂,二氧化锰为激发剂,硬脂酸钙为稳定剂,聚丙烯酰胺为增稠剂,通过化学发泡法制备内部含有大量密闭气孔的镁系无机轻质材料。探讨了水灰比(镁盐水用量与氧化镁粉比率)对镁质无机轻质材料表观密度、压缩强度、弯曲强度、孔结构及耐水性的影响规律。实验结果表明,水灰比不仅影响镁系无机轻质材料的孔结构和发泡成型,对晶体结构也有较大影响。随着水灰比增大,浆体稠度降低,镁系无机轻质材料的表观密度减小,孔结构形态逐渐得到改善,力学强度和耐水性则是先增大后减小。在水灰比为1.4时,强度相峰值最大,镁系无机轻质材料压缩强度和弯曲强度最大,耐水性最佳,同时平均孔径较小,孔隙率和圆度值最接近开普勒理想模型数值,表观密度仅为0.41g/cm~3,适合作为节能轻质墙体材料使用。     

聚对苯二甲酸乙二醇酯滤料超疏水表面的制备及性能

以聚对苯二甲酸乙二醇酯(PET)滤料为基体材料,正硅酸乙酯(TEOS)和甲基三乙氧基硅烷(MTES)为改性剂,采用溶胶-凝胶法,制备超疏水性PET滤料。在此基础上,采用场发射扫描电子显微镜(FESEM-EDS)、傅里叶变换红外光谱仪(FTIR)和接触角测试仪研究PET滤料改性前后的微观形貌、表面组成以及接触角等参数。研究表明:改性前后滤料微观孔隙率基本不变,TEOS改性的PET(T-PET)滤料由于形成大量亲水性的—OH基团,呈现完全润湿性;MTES改性的PET(M-PET)滤料表面存在疏水性的—CH₃基团,呈现高疏水性;TEOS和MTES共同改性的PET (MT-PET)滤料表面由于大量疏水性的—CH₃基团,且有大量的含有—CH₃基团SiO₂纳米粒子沉积在纤维表面,降低了滤料表面能,形成纳米级粗糙、褶皱甚至凸起形态;MT-PET的静态接触角(WCA)为(158.8±1.2)°,流失角(WSA)为(6.9±1.5)°,达到超疏水状态。此外,通过喷涂湿粉尘和水中浸泡(室温)滤料对比试验,表明MT-PET滤料具有良好的自清洁性能与稳定性。综上,本文中MT-PET超疏水滤料的制备,对于高湿环境下的袋式除尘材料的研究开发具有潜在价值。      

Hydrothermal corrosion behavior of iron aluminide under SCWO conditions

Fe₃Al based iron aluminide was tested under supercritical water oxidation (SCWO) conditions to explore its possible use as a reactor material for hydrothermal processes. Degradation resistance of the material were evaluated in distilled water at 450 °C and 300 atm in a closed reactor. The results of the kinetics studies, metallographic observations as well as phase and chemical analysis of the corrosion products indicated limited applicability of iron aluminide in SCWO conditions.     

Plant structured textile fabrics

The unique internal structure and network of plants are responsible for their superb water transpiration ability. Here we show that the emulation of the plant structure in textile fabrics can bring about a new type of material, which has very fast initial water absorption and water transmission rate through it (The water transmission rate can be 2-3 times of the evaporation rate from the free water surface). The material is therefore ideal for application as clothing fabrics, since it can efficiently facilitate the transport of sweat from the skin so as to keep the wearer dry and comfortable. It would also be an excellent covering material for applications such as carpets, manmade grass, and geotextiles, because of its advantage in keeping the under-covered area dry. This work provides a unique example of how the superb transport mechanisms of the plant structure can be applied in engineering materials.     

Application of the powder of porous titanium carbide ceramics to a reusable adsorbent for environmental pollutants

The aim of this study is to investigate the utilization of the powder of porous titanium carbide (TiC) ceramics as a novel adsorbent or a material for solid-phase extraction (SPE). The adsorption and elution of inorganic and organic pollutants, Pb(II), 2,4,6-trichlorophenol (TCP), perfluorooctane sulfonate (PFOS), and perfluorooctanoic acid (PFOA), to the material were evaluated. The cartridge packed with TiC ceramics powder was used for the extraction test of pollutants. The solution containing pollutants at 1.0 μg mL(-1) was passed through the TiC cartridge, and the substances were almost quantitatively removed. Furthermore, the pollutants retained in the cartridge were eluted with 3N HCl for Pb(II) and with methanol for organic pollutants. The recoveries of pollutants were over 80%. In addition, we used the TiC cartridge for the solid-phase extraction of water samples (500 mL each of the distilled water and the river water) by adding pollutants at determined concentrations. Every pollutant was adsorbed almost quantitatively, and eluted by 3N HCl or methanol. From these results, we concluded that the powder of porous TiC ceramics is a useful reusable adsorbent for the water cleanup and solid-phase extraction.     

不同发泡倍率聚乙烯醇基缓冲包装材料性能

目的 探究聚乙烯醇(PVA)基发泡材料的缓冲包装性能,为PVA基发泡材料应用于易渗出水溶性液体的产品包装提供一定的理论依据和实践经验。方法 采用化学发泡法制备不同发泡倍率的PVA基发泡材料,研究其微观结构、吸水性能和不同条件下的缓冲性能。结果 不同发泡倍率下,5种密度PVA基发泡材料均具有良好的吸水性和保水性,且吸水率越高,保水性越差。在干燥状态下,材料的质地较硬,且其缓冲性能随着发泡倍率的增大而减小,材料吸水后变得柔软且富有弹性,当吸水率达到58.0%后,材料的缓冲性能则急剧下降。结论 经综合比较,密度为0.146 g/cm³ 的PVA基发泡材料具有良好的吸水性能、保水性能和缓冲性能,在材料的吸水率低于58.0%时,可满足易渗液体容器的锁水和缓冲包装需求。