钢液凝固过程中稀土夹杂物的显微形貌及形成机制的研究

用透射电镜和扫描电镜研究了钢液凝固过程中形成的稀土夹杂物的结构类型及类型及形貌，并运用热力学理论分析其形成过程。研究结果表明，在钢液凝固过程中，随着硫氧比的提高，稀土与氧硫反应产物依次是ＲＥ２０３、Ｒ３２Ｏ３与ＲＥ２９２Ｓ的复合物，ＲＥ２Ｏ２Ｓ以及ＲＥ２Ｓ３，此外还少量ＲＥＯ３。ＲＥ２ＯＥ呈典型胞状，ＲＥ２９Ｏ２Ｓ则为表面光滑的团球状。     

MICROCALORIMETRIC AND DEHYDROGENATION ACTIVITY STUDIES OF Pt/γ-Al_2O_3 AND Pt-Sn/γ-Al_2O_3 CATALYSTS

ＭＩＣＲＯＣＡＬＯＲＩＭＥＴＲＩＣＡＮＤＤＥＨＹＤＲＯＧＥＮＡＴＩＯＮＡＣＴＩＶＩＴＹＳＴＵＤＩＥＳＯＦＰｔ／γ┐Ａｌ２Ｏ３ＡＮＤＰｔ┐Ｓｎ／γ┐Ａｌ２Ｏ３ＣＡＴＡＬＹＳＴＳ＊ＪｉａＪｉｆｅｉ１，ＳｈｅｎＪｉａｎｙｉ２，ＸｕＺｈｕｓｈｅｎｇ１，ＧｅＸ...     

RE2O3-Al2O3-SiO2玻璃连接氮化硅合成复相陶瓷的研究

采用Ｙ２Ｏ３－Ａｌ２Ｏ３－ＳｉＯ２－Ｘ稀土玻璃进行氮化硅复相陶瓷的连接。用四点弯曲方法测定不同连接工艺下的连接强度。并对连接界面进行ＳＥＭ、ＥＰＭＡ和ＸＲＤ分析。液相钎料玻璃在界面上与氮化硅反应，形成氮化硅／Ｓｉ２Ｎ２Ｏ／Ｙ（Ｌａ）－Ｓｉａｌｏｎ玻璃／Ｙ（Ｌａ）－Ｓｉａｌｏ玻璃的梯度层界面。接头强度随着保温时间、妆温度的增加，先增后。 在ＹＡＳ钎料中添加氧化镧，可以提高接头的高温强度。ＬａＹＯ３的     

CuO／CeO_2／γ－Al_2O_3催化剂的结构及氧物种

应用ＸＲＤ、ＥＳＲ及ＸＰＳ方法研究了ＣｕＯ／ＣｅＯ２／γ－Ａｌ２Ｏ３催化剂的体相及表面结构，并对催化剂表面氧物种进行了表征．实验结果表明，ＣｅＯ２使Ｃｕ２＋还原为低价钢离子和增加钢化合物的分散性．催化剂中ＣｅＯ２含量高时，表面有Ｏ２－和Ｏ－物种，而ＣｅＯ２含量低时，只有Ｏ２－物种．     

烯丙基硫脲与支持电解质阴离子在银电极上共吸附的拉曼光谱

用表面增强拉曼散射光谱（ＳＥＲＳ）和时间分辨ＳＥＲＳ光谱（ＴＲＳＥＲＳ）等技术首次研究了烯丙基硫脲（ＡＴＵ）在ＨＣｌＯ４、Ｈ２ＳＯ４和ＨＮＯ３介质中与无机阴离子在银电极上的电化学共吸附行为．提出ＡＴＵ很可能以Ｓ端与银电极表面形成化学吸附键，仲氨基相对伯氨基距离表面较近，整个分子偏向烯丙基一侧倾斜吸附在表面上．ＣｌＯ－４、ＳＯ２－４和ＮＯ－３等弱吸附无机阴离子均能被ＡＴＵ诱导共吸附在其质子化了的仲氨基上，这３种无机阴离子被ＡＴＵ诱导共吸附的强弱顺序是ＣｌＯ－４＞ＳＯ２－４＞ＮＯ－３．被诱导共吸附的无机阴离子对ＡＴＵ在电极表面的化学吸附起到稳定剂的作用，有利于ＡＴＵ在电极表面形成致密的吸附层     

CROSSED SUPERSONIC MOLECULAR BEAM STUDY OF Cl+CH_2I_2→ICl+CH_2I

ＣＲＯＳＳＥＤ　ＳＵＰＥＲＳＯＮＩＣ　ＭＯＬＥＣＵＬＡＲ　ＢＥＡＭ　ＳＴＵＤＹ　ＯＦ　Ｃｌ＋ＣＨ＿２Ｉ＿２→ＩＣｌ＋ＣＨ＿２ＩＣＲＯＳＳＥＤＳＵＰＥＲＳＯＮＩＣＭＯＬＥＣＵＬＡＲＢＥＡＭＳＴＵＤＹＯＦＣｌ＋ＣＨ＿２Ｉ＿２→ＩＣｌ＋ＣＨ＿２ＩＪｉａｎＸ...     

RE（CCl3COO）3（Phen）2·nH2O混配配合物的合成,性质及…

利用水和乙醇混合溶剂合成了稀土三氯醋酸盐与２份１，１０－邻菲绕啉（ｐｈｅｎ）配合物ＲＥ（ＣＣｌ３ＣＯＯ）３（ｐｈｅｎ）２·ｎＨ２Ｏ（ＲＥ＝Ｎｄ，Ｓｍ，ｎ＝０；ＲＥ＝Ｅｕ，ｎ＝２）的单晶。结构测定表明，Ｎｄ（ＣＣｌ３ＣＯＯ）３（ｐｈｅｎ）２为三斜晶系，每个三氯醋酸盐均以双齿配位，２个ｐｈｅｎ亦为双齿配位，故配位单元中钕为１０配位；Ｅｕ（ＣＣｌ３ＣＯＯ）３（ｐｈｅｎ）２·２Ｈ２Ｏ为单斜晶系，１个三氯醋     

DECOMPOSITION OF KNO_3/γ-Al_2O_3 AND THE FORMATION OF SURFACE BASE SITES

ＤＥＣＯＭＰＯＳＩＴＩＯＮＯＦＫＮＯ３／γ┐Ａｌ２Ｏ３ＡＮＤＴＨＥＦＯＲＭＡＴＩＯＮＯＦＳＵＲＦＡＣＥＢＡＳＥＳＩＴＥＳ＊ＴｕＭａｉ，ＬｉＤａｔａｎｇ，ＺｈｕＪｉａｎｈｕａ，ＳｈｅｎＪｉａｎｙｉ＊＊（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，Ｉｎｓ...     

PROPERTY OF Al F3 CATALYSTSPREPARED BY FLUORINATION OF Al2 O3 WITH HF

ＰＲＯＰＥＲＴＹＯＦＡｌＦ３ＣＡＴＡＬＹＳＴＳＰＲＥＰＡＲＥＤＢＹＦＬＵＯＲＩＮＡＴＩＯＮＯＦＡｌ２Ｏ３ＷＩＴＨＨＦＬüＪｉａｎ＊，ＳｈｉＬｅｉ，ＹａｎｇＨｕｉ′ｅ，ＣｈｅｎＳｈｕｋａｎｇ，ＲｅｎＪｉａｎｇａｎｇ，ＬｉＨｕｉｌｉ，ＰｅｎｇＳｈａｏｙｉ...     

γ-Al2O3修饰中孔陶瓷膜的气体渗透作用

ＧＡＳＰＥＲＭＥＡＴＩＯＮＯＦγ┐Ａｌ２Ｏ３ＭＯＤＩＦＩＥＤＭＥＳＯＰＯＲＯＵＳＣＥＲＡＭＩＣＭＥＭＢＲＡＮＥＸｕＺｈｏｎｇｑｉａｎｇ，ＣｈｅｎＱｉｎｇｌｉｎｇ（ＳｈａｎｇｈａｉＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅｏｆＰｅｔｒｏｃｈｅｍｉｃａｌＴｅｃｈ...     

氢化物发生-原子荧光光谱法测定核电用钢中痕量锡

提出了氢化物发生-原子荧光光谱法测定核电用钢中痕量锡的方法。样品在酒石酸溶液存在下,用盐酸-硝酸(3+1)混合酸溶解,用50 g·L-1硫脲-抗坏血酸混合溶液作掩蔽剂,20 g·L-1硼氢化钾溶液作为锡(Ⅳ)的还原剂,氢化反应在pH 5.0~5.5介质中进行,锡的质量浓度在50μg·L-1范围以内与相应的荧光强度呈线性关系,方法的检出限(3s/k)为0.4μg·L-1。应用此方法分析了核电用钢及不锈钢标准样品中锡的含量,并与电感耦合等离子体原子发射光谱法作了比较,测定值与标准值相符,结果的相对标准偏差(n=8)均小于4.5%。     

模拟生物膜方法研究钢在海水中的腐蚀行为

近年来,微生物腐蚀受到广泛重视。本文根据生物膜的结构特征,以含羧酸官能团的β－Ｄ甘露糖醛酸单元等构成的天然高分子多糖凝胶沉积于电极表面,形成模拟生物膜,初步建立起模拟生物膜环境的实验方法,并探讨了模拟海水ＮａＣｌ溶液中生物膜对１０ＣｒＭｏＡｌ、Ｅ２低合金钢和１８－８不锈钢腐蚀行为的影响。采用极化曲线法、电偶电流测试及交流阴抗谱等电化学方法研究了上述材料在模拟生物膜环境中的腐蚀电化学行为,得到了一些     

Determination of hydrogen in stainless steels by spark-source mass spectrometry

A spark-source mass spectrometric (SSMS) method capable of determining traces of hydrogen in micro-volumes of metals was developed by using a pointed metal probe technique. The hydrogen background was decreased to μg g^?1 levels by the combination of a method in which the sample in the ion source is baked under vacuum at 323–343 K for more than 25 ks and a liquid nitrogen or liquid helium cryogenic pump method. This method was applied to the analysis of austenitic stainless steels at μg g^?1 hydrogen levels, and the relative standard deviation was within 20% for samples with hydrogen concentrations ranging from 2 to 4 μg g^?1. The relative sensitivity coefficent was 2.3 (Fe=1).     

Surface and grain boundary segregation in 16MND5 steel

An adequate model of quantification when there are many segregating elements is required for industry and research. Hence, for the first time, surface segregation kinetics on industrial 16MND5 steel was studied by XPS spectroscopy at temperatures ranging from 500 to 600 ^oC. From measurements that highlight the competitive segregation of P, S, Sn, Sb, As, and Cu impurities at the surface, a quantification model was developed and successfully used to deduce the surface concentrations during segregation kinetics as well as derive the corresponding diffusion coefficients. We observed that phosphorus and sulfur are the first elements covering the surface, then they are supplanted by others' impurities. This result may reflect impurities segregation behavior at the grain boundaries that impacts mechanical behavior of the material. Indeed, to further the research, 16MND5 samples were aged in the same range of temperatures. Then, Auger spectroscopy measurements at grain boundaries were conducted on broken samples exhibiting intergranular cracking. Results show that phosphorus is the only segregating element present at grain boundaries after 2 months of aging. Importantly, it appears that phosphorus grain boundary segregation kinetics is significantly lower than at surface. Copyright © 2017 John Wiley & Sons, Ltd.     

模拟地热水中304不锈钢管和镀锌钢管的腐蚀与结垢

采用扫描电子显微镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)和电化学测试的方法研究了304不锈钢管和镀锌钢管在模拟地热水(我国中部平原地热水的环境条件)中的腐蚀与结垢行为.结果表明,不锈钢管的结垢产物为"针"状物,其组成主要为CaCO3和MgCO3;镀锌钢管的腐蚀与结垢产物为"球"状物和"针"状物,其组成主要为Zn(OH)2、ZnO和CaCO3;腐蚀产物与结垢产物在晶核的形成生长过程中往往存在相互作用,同时它们在基材表面的分布对镀锌钢管的进一步腐蚀产生一定的抑制作用.     

电化学动电位再活化法(EPR法)的应用研究

应用电化学动电位再活化法(EPR法)评价不锈钢复合板和低铬铁素体不锈钢的晶间腐蚀敏感性. 结果表明,以电化学动电位再活化法测得的反向扫描与正向扫描电流最大值之比（ir / ia）评价堆焊不锈钢复合板00Cr17Ni14Mo2/20R复层晶间敏感性与传统H2SO4-CuSO4-Cu法测定的结果吻合甚好;评价爆炸复合板复层06Cr13R低铬铁素体不锈钢晶间腐蚀敏感性与草酸浸蚀法测定的也一致. 说明该法可以成功用于定量、定性地评价不锈钢复合板和低铬铁素体不锈钢的晶间腐蚀敏感性.     

不锈钢、耐热钢系列化学分析标准物质的研制

介绍0Cr18Ni10Ti、OCr18Ni12M02Ti、OCr17Ni4Cu4Nb、1Cr25Ni20Si2、1Cr13和2Cr13等6种典型不锈钢和耐热钢系列化学分析用标准物质的成分设计、制备工艺、定值方法及数据处理。采用中频感应炉冶炼．用F方差法检验均匀性,8家实验室采用不同分析方法协同定值。所研制的系列标准物质定值元素多,多数元素含量呈梯度分布,既可单独使用,也可成套使用。     

Kinetic approach to mild steel corrosion

Summary The rate of steel corrosion in hydrochloric acid solutions in the absence and in the presence of inhibitors is studied. It is found that the process dynamics is described by an exponential kinetic equation of self-accelerating reactions in the absence of inhibitor and by an equation of a zero order in its presence.     

分光光度法测定钢电镀层中的铬(Ⅵ)

建立了用弱碱性溶液萃取—二苯卡巴肼分光光度法测定电镀钢中铬的方法。结果表明,在Cr(Ⅵ)质量浓度为0.0~1.0 mg/L的范围内与吸光度线性关系良好,r=0.999 8,加标回收率为97.0%~105.2%,相对标准偏差RSD为3.75%。     

Microprecipitation in boron-containing high-carbon steels

The dissolution and precipitation of boron have been studied in a high-carbon steel. Boron was found in different states: boron oxides, boron carbonitrides and iron-borocarbides Fe₂₃(B,C)₆. The dissolution of iron-borocarbides in austenite is complete at 1100 °C and precipitation along grain boundaries of this boron-bearing phase was observed after water-quenching from high austenitizing temperature. Therefore, boron precipitates along grain boundaries before pearlite nucleation.