Effect of corrosion on mass loss, and high and low cycle fatigue of reinforcing steel

The effect of various levels of corrosion on the mass loss, and the high and low cycle fatigue of BSt500_s steel reinforcement were experimentally investigated. The mass loss, the fatigue limit, and the life expectancy were reduced by 1.5 to 2.9%, 20 to 40%, and 56 to 76%, respectively, according to the corrosion level. Low cycle strain-controlled fatigue testing under a ±1% constant amplitude strain showed that the corroded steel bars exhibit a gradual reduction in the load-bearing ability, the available energy, and the number of cycles to failure. The considerable reduction in the fatigue limit took place because the mass loss led to a reduction of the exterior hard layer of martensite and a drastic drop in the energy density of the corroded specimens, thus developing stress concentration points that are highly localized at imperfections, and especially in the pits and notches of the rib bases of the corroded steel. Because corrosion and cycle fatigue are time-dependent, it seems that steel reliability is also time-dependent.     

特殊结构吉米奇(Gemini)季铵盐性能及其在油田中的应用

对几种特殊结构吉米奇(Gem in i)季铵盐的性能进行研究,其中包括含有聚氧乙烯基、超支化、不对称吉米奇季铵盐,并对其在油田三采驱油、油田防膨、油田杀菌方面的应用进行了综述。     

蒸馏塔顶系统缓蚀剂的研制

针对辽河原油的特点 ,锦西石化公司研究院与中科院金属所合作 ,以合成的咪唑啉衍生物和炔氧甲基季铵盐为主要组分 ,复配成功抑制HCI -H2 S -H2 O体系腐蚀的水溶性缓蚀剂IMC - 97-C。经实验室评价和现场中试评价试验证明 :IMC - 97-C缓蚀性能优良 ,可以有效地抑制蒸馏塔顶低温冷凝冷却系统的腐蚀。当pH值控制在 6.0～ 8.0时 ,塔顶露点区的腐蚀率仅为 0 .0 6mm/a ,远低于注氨时的 0 .3 2mm/a的腐蚀速率 ,而且对汽油质量无不良影响     

吐哈油田盐膏层钻井液技术

吐哈油田西部各区块富含盐膏、膏质泥岩层 ,钻井时易发生复杂情况与事故。通过几年来钻井液技术的研究与实践 ,优选应用了聚合物抗盐钻井液 ,配合钻井工程技术措施 ,解决了盐膏层钻井技术难题 ,钻井质量逐年提高。     

Comparison of corrosion behavior of Zl104 alloy at as —cast and heat treatment states

The corrosion behavior of ZL104 alloy at different states(as-cast and heat treatment) in salt spray corrosion (SSC) was studied.The results show that the sample treated after refinement and modifciation has the least corrosive resistance compared with the sample bearing as -cast stucure at the beginning of the corrosion.As the corrosion process continued.however,the trend reversed itself.After 44h continuous corrosion,the corrosive rates of all samples tend to be stable.After experiments,the sample bearing as -cast structure had the most corrosive products on the surface whereas the sample being refined and modified had the least products.The Fourier transformation infrared spectroscopy(FTIR) analyses of the corrosion products show that these products are composed of hydroxyl-containing substances.     

Acoustic emission in host-rock material for radioactive waste disposal: comparison between clay and rock salt

The use of clay masses for radioactive waste disposal requires a comprehensive analysis of fracture processes in clay. Acoustic emission (AE) was used to obtain a better insight into damage evolution during uniaxial loading of Boom Clay specimens. A comparison of AE in clay and rock salt shows a much lower AE activity in clay. This, together with the higher attenuation, would inhibit the use of the AE technique for large-scale in-situ monitoring in clay masses. Cyclic uniaxial tests showed that, similarly to rock salt, clay exhibits a very well-pronounced Kaiser effect in AE with Felicity ratios around unity. The Kaiser effect takes place at different loading stages (before and at the flow limit) and, during reloading, it coincides with the deformation curve inflection. Further research is required to study the applicability of the Felicity ratio as a measure of the intensity of healing processes in clay. Electronic Publication     

Effect of Sodium Chloride Particle Size and Shape on Nonelectrostatic and Electrostatic Coating of Popcorn

ABSTRACT: Sodium chloride of different shapes (hollow pyramid, crushed flake, cube, and porous cube) and sizes (50-200 mesh) were applied by nonelectrostatic and electrostatic powder coating to popcorn coated with 1.2 to 3.3% soybean oil. Electrostatic coating was more efficient than nonelectrostatic in all cases. The smaller the particles, the higher the coating efficiency for both electrostatic and nonelectrostatic coating. Crushed flake and hollow pyramid were more efficient than cube and porous cube shapes. Coating efficiency improved as the oil content increased for nonelectrostatic but not electrostatic coating. Use of electrostatic coating can reduce waste and provide a more efficient coating method by decreasing seasoning or oil needed to reach the target level.     

Improvement in Oxidation Resistance of Stainless Steel by Molten-Salt Electrodeposition of La

Improvement in the oxidation resistance of SUS304 stainless steel was accomplished by electrodeposition of La in a molten salt. The electrolysis of La was conducted using a potentiostatic-polarization method in an equimolar NaCl–KCl melt containing 3.5 mol. LaF ₃ at 1023 K. Observation of the specimen surface after polarization at –1.8 V (vs. Ag/Ag⁺ (0.1)) for 0.18 ks showed that La particles were uniformly dispersed on the surface. The oxidation resistance of the electrodeposited stainless steel was significantly improved as compared with the untreated stainless steel. The scale formed on the untreated stainless steel after oxidation was thick and consisted of Fe₂O₃ and Fe₃O₄, whereas the scale formed on the elecrodeposited stainless steel was extremely thin, and mainly consisted of Cr₂O₃.     

艾丁湖天然无水芒硝形成机理的研究

文章对艾丁湖天然无水芒硝的分布、特征、形成机理进行了研究 ,得出天然无水芒硝的成因 ,为利用太阳能技术生产无水芒硝提供理论依据。     

加食盐煅烧提高石灰活性机理的研究

采用扫描电子显微镜（ＳＥＭ５０５）观察ＣａＯ晶体结构变化，电子探针测定其成分。发现加食盐煅烧能够大幅度地提高石灰活性度。被蒸发的ＮａＣｌ离子扩散渗入ＣａＯ晶体中，使晶粒结构发生变化，从而晶粒间的气孔率增加，气孔大，宽增大。