碳钢和铁-铬-镍基合金在相变储能材料用熔融共晶氯化钠和氯化镁中的腐蚀行为（英文）

研究了3种铁-铬-镍基合金(Fe-Cr-Ni)和一种碳钢试样在520℃熔融共晶NaCl-MgCl_2盐中的腐蚀行为。结果表明,碳钢试样晶界处Fe原子优先变为亚铁离子(Fe~(2+))和铁离子(Fe~(3+)),发生了严重的沿晶腐蚀,但表面形成了厚而致密的MgO壳,对试样起到了一定的保护作用。3种Fe-Cr-Ni基试样表面也形成了MgO壳,但因铬元素优先被腐蚀,试样表面形成了疏松的富Ni骨架状微观组织结构,MgO壳或颗粒极易剥落,未能起到有效的保护作用;Cr含量越高,腐蚀越严重。对于太阳能储能技术,在廉价的铁基合金中添加镍元素作为熔融氯化盐相变储热介质的容器或者管道材料,具有良好发展前景。     

碳钢和铁-铬-镍基合金在相变储能材料用熔融共晶氯化钠和氯化镁中的腐蚀行为

研究了3种铁-铬-镍基合金(Fe-Cr-Ni)和一种碳钢试样在520℃熔融共晶NaCl-MgCl2盐中的腐蚀行为。结果表明,碳钢试样晶界处Fe原子优先变为亚铁离子(Fe2+)和铁离子(Fe3+),发生了严重的沿晶腐蚀,但表面形成了厚而致密的MgO壳,对试样起到了一定的保护作用。3种Fe-Cr-Ni基试样表面也形成了MgO壳,但因铬元素优先被腐蚀,试样表面形成了疏松的富Ni骨架状微观组织结构,MgO壳或颗粒极易剥落,未能起到有效的保护作用;Cr含量越高,腐蚀越严重。对于太阳能储能技术,在廉价的铁基合金中添加镍元素作为熔融氯化盐相变储热介质的容器或者管道材料,具有良好发展前景。     

高镍奥氏体球墨铸铁涡轮增压器壳体材质及工艺研究

对高镍球铁涡轮增压器壳铸件的开发和研究进行了系统总结,包括高镍奥氏体球铁材质成分和铸件工艺设计,球化剂、孕育剂的选择和制备,高镍球铁涡壳铸件表面气孔缺陷和缩孔缩松缺陷的消除,高镍奥氏体球铁铸造性能的测试以及高镍球铁涡轮增压器壳铸件理化检测问题.     

X射线荧光光谱法测定高密度钨合金中铁和镍

采用氧化、熔融对样品进行处理,以X射线荧光光谱法测定铁、镍含量。经过LiF220晶体分光,用闪烁计数器对铁、镍进行测定。铁、镍工作曲线线性良好,相关系数均为0.9999,检出限分别为0.004%和0.008%;与人工配制标样理论值比较,铁、镍测定的绝对偏差小于0.10%;RSD分别为0.78%和0.71%。方法简单、快速、准确,可用于高密度钨合金中铁和镍的测定。     

不同氧化剂对单镍盐电解着色的影响

研究了不同氧化剂对单镍盐电解着色的影响。结果表明,无钠宽温氧化剂与常温氧化剂对单镍盐电解着色影响甚微,可以生产稳定的香槟色铝型材料,但含钠宽温氧化助剂对单镍盐电解着色影响较大,不易得到均匀稳定的香槟色铝型材料。     

氨基磺酸盐镀铁镍合金组织结构的研究

以扫描电镜和χ射线衍法对氨基磺酸盐镀液沉积的铁镍合金组织结构进行研究。实验结果表明；在通常情况下，铁合金的显微组织是典型的柱状结构，其中镍为置换固溶，镀层中还含有少量的氢，氢为间隙固溶。     

光亮氯化物电镀锌铁合金工艺研究

采用霍尔槽试验成功了一种光亮氯化物电镀低铁含量的锌铁合金工艺,探讨了光亮剂、主盐、导电盐、稳定剂、工艺条件的影响,检测了镀液、镀层性能。结果表明：本工艺所得镀层光亮如镜,白钝酷似镍层,主要性能指标优于纯锌镀层,适用于钢铁零部件的高耐蚀性电镀。     

铸态高镍奥氏体球墨铸铁稳定化生产

分析了一些主要元素对高镍奥氏体球铁组织和性能的影响,确定了合理的内控化学成分。球化处理采用冲入法,镍镁合金球化剂用量为铁液重量的0.7%~0.9%,球化后高镍奥氏体球铁Mg残留量为0.07%~0.09%。采用硅铁和硅钡孕育剂炉前孕育,孕育剂用量为铁液量的1.0%~1.5%。采用以上工艺方法生产的铸态高镍奥氏体球铁力学性能合格率明显提高。     

氢气作用下硅镁型红土镍矿的低温还原特性

以含镍0.82%、含铁9.67%的某硅镁型红土镍矿为原料开展氢气低温还原实验研究,考察还原温度、还原时间、氢气浓度及矿物粒度对镍、铁金属化率的影响。结果表明:在还原温度为600℃、还原时间90 min及氢气浓度为60%(体积分数)的条件下,红土镍矿中镍、铁金属化率分别达到95%和42%。当矿物粒度小于380μm时,矿物粒径对镍、铁金属化率的影响并不明显。随着还原温度的升高,镍铁合金([Fe,Ni])的衍射峰呈现先增强后减弱的趋势,在600℃时达到最大。且随着温度的进一步升高,无定型含镁硅酸盐重结晶生成镁橄榄石相,阻碍镍、铁的还原。通过氢气低温还原,矿物中的氧化镍几乎完全还原,部分铁被还原为金属铁与镍形成了镍铁合金,大部分的铁被还原为铁的低价氧化物。     

红土镍矿还原焙烧-磁选制取镍铁合金原料的新工艺

采用钠盐添加剂强化红土镍矿的还原焙烧-磁选,确定了添加剂存在下适宜的焙烧和磁选技术参数,开发出红土镍矿还原焙烧-磁选制取镍铁合金原料的新工艺.结果表明:钠盐添加剂具有显著降低焙烧温度、大幅提高产品镍、铁品位和回收率的作用;对一种含镍1.58％、铁22.06％的红土镍矿配加添加剂后,在还原温度1 100℃、还原时间60 min、磁场强度0.1T的条件下,磁性产品的镍、铁品位可分别从无添加剂时的2.0％、57.2％提高到7.5％、80.5％,镍、铁回收率也相应从19.1％、33.6％增加到82.7％、62.8％.XRD结果表明:红土镍矿在无添加剂作用下经还原焙烧-磁选所得的磁性产物中仍有部分镁橄榄石及顽火辉石存在;而有添加剂存在时,还原生成的镍铁合金通过磁选可与非磁性脉石成分得到更为有效的分离,产品可作为不锈钢的生产原料.     

Untersuchungen über die Kathodenwirkung von Eisensulfid und Mangansulfid auf die Korrosion von Eisen in dreiprozentiger Natriumchloridlösung

Studies on the cathodic effect of iron sulfide and manganese sulfide on the corrosion of iron in a three percent sodium chloride solution In the galvanic element iron/sodium chloride solution/iron sulfide and in the element iron/sodium chloride solution/manganese sulfide, flushed with nitrogen or air, the sulfides become the cathode and the iron is anode. Upon short circuiting the electrodes a strong cathodic polarisation of the sulfides occurs. However, only if the iron is in contact with iron sulfide in the air-flushed sodium chloride solution the corrosion of the iron is enhanced because of considerable anodic polarisation. The corrosion of the iron electrode is increased corresponding to the increase in cathodic area. According to these results inclusions of iron sulfide or manganese sulfide act as local cathodes but cannot cause pitting corrosion of unalloyed steels in a neutral chloride solution.     

Electrochemical behavior and corrosion of iron in aqueous sulfidic solution

This paper discusses the electrochemical behavior and corrosivity of aqueous sulfidic solutions with reference to iron and carbon steel. The chemistry of aqueous sulfidic solutions is reviewed with particular emphasis on stability of various sulfur species in aqueous solutions as a function of pH and solution potential. The thermodynamic predictions of corrosion processes for iron in sulfidic solution are discussed in terms of the potential pH equilibrium diagrams. Considerable discussion of the corrosion and electrochemical behavior of iron in sulfidic solutions includes the role of solution composition on corrosion and polarization behavior. The influence of surface films on corrosion in these systems is also discussed. The paper concludes with a discussion of the role solution composition on hydrogen absorption and embrittlement of iron and carbon steel.     

磁场对铁腐蚀过程中阴极析氢和阳极溶解的影响

用动电位扫描法研究了０．５Ｔ磁场下纯铁在三种典型介质中的阴极极化曲线和两种介质中的阳极极化曲线．发现磁场会引起一个新的过电位一磁致过电位ｍａｇ,使铁上阴极析氢和铁的阳极溶解有不同程度的加速,尤以在酸性介质中为甚．认为这是由于磁场使铁－水溶液界面抗磁性离子的水合作用减少和使Ｆｅ２＋有吸附于铁电极表面的倾向,导致双电层结构的改变和腐蚀体系的活性增加．     

高硅铸铁耐腐蚀性的研究

采用失重分析、金相分析等试验方法研究了高硅铸铁在不同环境下的耐腐蚀性能,并对高硅铸铁、普通灰铸铁及白口铸铁的耐腐蚀性进行比较。结果表明,高硅铸铁在各种腐蚀介质中均有良好的耐蚀性,腐蚀溶液的浓度对高硅铸铁的腐蚀速度有较大影响。因为硅的存在,高硅铸铁的耐蚀性明显优于普通灰铸铁和白口铸铁;而白口铸铁因其基体组织为Fe3C,在酸性溶液中的耐腐蚀性能又优于灰铸铁。     

Magnetism-induced solid solution effects in intermetallic Ni60Al40

In this study, experimental work on solute effects in an intermetallic alloy, NiAl, has been complemented by first-principles quantum mechanical calculations to investigate the effect of iron and cobalt solutes on lattice parameter and hardening. Ternary additions of iron and cobalt with similar atomic sizes were added to replace nickel in NiAl containing 40% Al. Cobalt solutes did not affect the lattice parameter or the hardening behavior of NiAl alloys. Iron solutes, on the other hand, substantially expanded the lattice, resulting in unusual solid solution softening. These results could not be explained from a consideration of the size mismatch based on the Goldschmidt radii for iron and cobalt atoms. From the contrasting behavior of the iron and cobalt solutes, magnetic interactions induced by iron atoms located on the aluminum sublattice have been identified as a new factor responsible for the unusual large lattice dilation and resultant solid solution softening in these intermetallic alloys.     

Polyaniline-coated iron: studies on the dissolution and electrochemical activity as a function of pH

Polyaniline coatings were electrodeposited from an oxalic acid solution onto iron and their electrochemical activity and corrosion protection properties studied as a function of pH. It was found that the coating (emeraldine salt) had a limited effect on the corrosion protection of iron in acidic solutions. However, in an alkaline borate solution, where the conducting polyaniline was converted to the emeraldine base, the coating had a clear beneficial effect on the local breakdown of iron by chloride anions; much higher pitting potentials were recorded following a 2 h immersion period for the polyaniline-coated substrate relative to the uncoated electrode. Relatively small anions, such as acetates, nitrates and borates, were transported readily across the polymer interface. However, the emeraldine base inhibited the transport of the much larger ethylenediamine tetraacetate (EDTA) species to the iron interface, preventing complexation of the iron by EDTA.     

Film Growth and Dissolution of Iron Ions at passive iron in neutral solutions containing chloride

The passivating oxide layer on iron grows by transfer of oxygen ions from the solution into the oxide. As expected theoretically, the dissolution rate of iron ions increases with the growth rate of the layer. In neutral solution the current efficiency for oxide growth is larger than in acid solutions. By addition of chloride to the solution the current efficiency is further enhanced, because chloride catalyzes the transfer of oxygen ions more strongly than the transfer of iron ions. Chloride in the solution does not change the ionic conductivity of the oxide to a measurable extent. During galvanostatic polarization in solutions containing chloride, fluctuations of the potential and of the dissolution rate of Fe(II) are observed. The frequency of the fluctuations increases with current density and chloride concentration.     

乙二胺对铸铁文物在脱氯溶液中的缓蚀作用

研究了模拟铸铁文物在加入乙二胺的2%NaOH脱氯溶液中的化学和电化学脱氯效果,用红外光谱(IR)和紫外光谱(UV)测试了采用加入乙二胺的碱性溶液处理后试片表面的成分,用动电位极化曲线和交流阻抗(EIS)技术研究了其耐腐蚀性能.结果表明,试片在该碱性脱氯溶液中化学和电化学脱氯速度和脱氯效果比传统的碱溶液脱氯方法有明显的提高;处理后的试片表面形成一层配合物膜,该表面膜明显提高了铁器的耐腐蚀性能.     

On the Mechanism of Oxide Films Formation on Pearlitic Steels in Nitrate Solutions

During exposing pearlitic steels to nitrate solutions, three mechanisms of iron transfer from the metal phase into solution are observed, depending on the solution pH and the presence of oxidants. The process yields either bivalent iron, colloid-disperse compounds of trivalent iron, or a lepidocrocite deposit. Oxide films thus formed have different protective value. A mechanism explaining the effect of different factors on the protective effectiveness of the oxide films is proposed.     

V(Ⅴ)-Fe(Ⅲ)-S(Ⅵ)-H2O系热力学研究与钒铁分离方法理论

针对酸浸液钒铁分离的难题,绘制298 K时V(Ⅴ)-Fe(Ⅲ)-S(Ⅵ)-H2O系中存在的各种离子随pH以及浓度变化的热力学平衡图,全面分析钒、铁物种随pH和钒、铁、硫浓度的变化规律,在此基础上提出相应的钒铁分离方法并进行理论分析。结果表明:强酸条件(?1相似文献