可视滴定法测定铝钒中间合金中的钒时称样量和滴定液浓度的优化

用可视滴定法测定铝钒中间合金中的钒时,对称样量和硫酸亚铁铵滴定液浓度的关系进行了探讨。实验发现,基体铝对于铝钒合金中钒的测定无影响。常见的铝钒合金范围为50%～60%,低于50%和高于标准上限0.5%钒含量的合金没有实验样品,通过向样品溶液中加入钒标准溶液可模拟铝钒合金试样。依据化学分析等物质量反应定律,选择不同钒含量的试验样品,对钒的称样量和滴定液浓度进行优化,确定了硫酸亚铁铵滴定液的浓度与滴定液消耗体积的合适关系。     

电感耦合等离子体原子发射光谱法同时测定高锰钢中多元素的含量

<正>锰是钢中的有益合金元素之一,又是冶炼的脱氧剂和脱硫剂,对提高钢的耐磨性作用明显^[1]。高锰钢具有较高的硬度和强度,其中硅、锰、磷、镍、铬、铜、钼、钒、钛等元素含量对其性能影响很大,是评价高锰钢品质的重要指标,也是其产品检测的必检项目。国家标准系列GB/T 223《钢铁及合金化学分析方法》中钢铁及合金中硅、锰、磷、镍、铬、铜、钼、钒、钛等元素的测定方法包括了重量法、滴定法、光度法及火焰原子吸收分光光度法等,     

萃取分离-高效液相色谱法同时测钢铁及合金中的锆和铪

锆和铪在钢中主要用来制作特殊用途的合金钢，它们可以改善钢的性能，提高钢的强度、导热性和导电性。而如何测定锆和铪的含量一直是研究的重要课题。锆和铪的化学性质极为相似，测定时相互严重干扰，同时由于钢铁及合金中的复杂的基体干扰，同时测定非常困难。本实验建立了一种离子对反相色谱法同时测定钢铁及合金中锆和铪的方法，采用钽试剂-苯萃取、硫酸反萃取排除共存离子W、Nb的干扰，用于钢铁及合金中锆和铪的同时测定，结果令人满意。     

合金的维生系——钒

随着材料科学的发展，金属钒及其化合物得到了越来越广泛的应用，并被誉为“合金的维生素”。在未来的发展中，钒及其化合物奖成为更加重要的稀有金属。本文介绍了钒的发现、分布、制备、性质及应用，并概述了钒与人体健康的关系。     

EDTA滴定法直接测定钒铝合金中的铝

正钒铝合金是生产钛合金和不含铁只含钒的特殊合金的添加剂,在钛合金中钒是一种强的稳定剂[1]。钒铝合金能改善合金的耐热性能与冷加工性能,使合金具有好的焊接性能和相当高的机械强度[2]。钒铝合金是一种新型合金材料,具有强度高、质量轻的特点,广泛应用于航空航天等尖端国防及民用工业领域[3]。由于基体钒和铝的比例随产品牌号变化较大,因此基体组成对测定的影响不容忽视,铝的成分及含量在钒铝合金的冶炼和使用过程中非常重要。目     

钢铁及合金中钼钨的连测

较快测定钢铁及合金中的钼和钨 ,一般采用硫磷混酸溶样 ,高温滴加硝酸氧化法 ,方法繁琐 ,不好控制 ,对含钨钒试样 ,测钼时用抗坏血酸还原出现不正常现象 ,且基体铁对钼、钨测定都有影响。本文采用磷酸 高氯酸 (2 + 1) 15ｍｌ加硝酸溶解氧化试样 ,不但操作简单 ,消除了含钨、钒试样测钼时 ,用抗坏血酸还原出现的不正常现象 ,而且使基体铁的影响消除。用于测定钢铁及合金中的钼、钨 ,准确度高 ,重现性好 ,容易掌握 ,完全可用于标准样品的标定。1　试验部分1.1　试剂与仪器抗坏血酸溶液 :10 0 ｇ·Ｌ- 1硫脲溶液 :30 ｇ·Ｌ- 1氯化亚锡溶液 :1…     

《钢铁及合金化学分析方法标准汇编》

本汇编共收集了100项钢铁及合金化学分析相关国家标准,内容包括冶金化学分析方法综合、钢铁及合金化学分析方法等。本汇编新增了7项冶金化学分析方法综合部分标准方法,将原钢铁产品分析方法部分更名为钢铁及合金化学分析方法,并废止3项标准方法,     

《钢铁及合金化学分析方法标准汇编》

本汇编共收集了100项钢铁及合金化学分析相关国家标准,内容包括冶金化学分析方法综合、钢铁及合金化学分析方法等。本汇编新增了7项"冶金化学分析方法综合"部分标准方法,将原"钢铁产品分析方法"部分更名为"钢铁及合金化学分析方法",并废止3项     

《钢铁及合金化学分析方法标准汇编》

本汇编共收集了100项钢铁及合金化学分析相关国家标准,内容包括冶金化学分析方法综合、钢铁及合金化学分析方法等。本汇编新增了7项"冶金化学分析方法综合"部分标准方法,将原"钢铁产品分析方法"部分更名为"钢铁及合金化学分析方法",并废止3项标准方法,     

《钢铁及合金化学分析方法标准汇编》

本汇编共收集了100项钢铁及合金化学分析相关国家标准,内容包括冶金化学分析方法综合、钢铁及合金化学分析方法等。本汇编新增了7项冶金化学分析方法综合部分标准方法,将原钢铁产品分析方法     

Extraction of vanadium(V) chelates with N-benzohydroxamic acid (BHA) and ammonium thiocyanate and its application in steel and rock analyses

A mixed-ligand complex of vanadium(V) with N-benzohydroxamic acid and thiocyanate formed at various acidities can be extracted into methyl isobutyl ketone, and used for photometric determination of trace amounts of vanadium in materials such as alloy steels and rocks. The absorption maximum of the violet mixed-ligand complex is at 535 nm. The values for the simple complex are 505 nm and molar absorptivity 7.4 x 10(3)l.mole(-1).cm(-1).     

电弧制样-电感耦合等离子体光谱分析法直接测定合金钢中的痕量元素

本文提出了电弧制样与电感耦合等离子体(ICP)相结合光谱直接测定合金钢中痕量元素的新方法。采用高压/低电流直流电弧放电作为试样蒸发的蒸发源,由于阴极弧斑在金属表面上方作快速均匀的移动,使试样剥离形成金属气溶胶,它在载气流(Ar)的作用下引入ICP。研究了试样的蒸发行为、放电气体介质、基体组成变化的影响及ICP工作参数等。用本法测定Co、Ni、Cr、Mn、Mo、Nb、Ta、Ti、V、W和Zr的检出限为0。x至xμg/g。分析了低、高合金钢试样,结果与NBS标准值吻合。     

钢在中国大陆的大气腐蚀研究

本文分析了我国七个试验点十七种钢的八年大气腐蚀试验结果 .表明 ,对碳钢和低合金钢 ,危害最大的污染是二氧化硫及氯离子 ,与公认一致 .但是 ,二氧化硫仅在开始头 1- 2年内危害突出 ,其后作用明显下降 .对非耐候钢 ,湿热条件在短期里对腐蚀的影响并不大 ,但长期暴露危害作用非常大 ,如果同时存在污染 ,更会造成很严重的腐蚀 ,值得特别注意 .由于腐蚀情况与时间因素有关 ,碳钢、低合金钢在不同腐蚀环境中 ,暴露第一年所显示的大气腐蚀性规律与长期暴露所显示的不同 ,如果用短期暴露数据判断钢的耐蚀性或环境的腐蚀性 ,都会导致错误的结论     

A rapid and selective method for direct gravimetric determination of vanadium(V) and its application to alloy steel and some rocks

N-o-Iodobenzoyl-o-tolyhydroxylamine has been synthesized and used as gravimetric reagent for direct determination of vanadium(V). The complex dried at 105-120 degrees has the definite composition VO(C(14)H(11)O(2)NI)(2)Cl. The method is simple, rapid, sensitive and selective and gives results reproducible within 0.1%. Precipitation is quantitative at room temperature over a wide range of acidity. The method is satisfactory for alloy steels and some rocks. The very low conversion factor (0.0632) is favourable for determining very small amounts of vanadium.     

A Rapid,Simple, and Sensitive Spectrophotometric Determination of Traces of Vanadium (V) in Foodstuffs,Alloy Steels,and Pharmaceutical,Water, Soil,and Urine Samples

Abstract

A rapid, simple, sensitive, and selective spectrophotometric method is investigated for the determination of traces of vanadium (V) in foodstuffs, alloy steels, and pharmaceutical, water, soil, and urine samples in aqueous DMF medium. The metal ion forms a green colored complex with 2-hydroxy-3-methoxy benzaldehyde thiosemicarbazone (HMBATSC) in an acidic buffer of pH 6.0. The green colored solution, having an absorbance maximum at 380 nm, is stable for more than 72 hours. Beer's law is obeyed in the range of 0.051–2.037 µg ml^?1. The molar absorptivity and Sandell's sensitivity of the method are found as 2.75 × 10⁴ l mol^?1 cm^?1 and 0.0018 µg cm^?2, respectively. The green colored complex has 1:2 [V(V)-HMBATSC] stoichiometry. The stability constant of the complex is determined as 3.267 × 10¹¹ by Job's method. The optimum reaction conditions and other analytical parameters are studied. A sensitive and selective second-order derivative spectrophotometry has also been proposed for the determination of V(V). The interference of various cations and anions are studied. The present method is successfully applied to the determination of vanadium (V) in foodstuffs, alloy steels, and pharmaceutical, water, soil, and urine samples.     

Activation analysis of vanadium in high alloy steels using manganese as internal standard

A method has been developed for the determination of vanadium in high alloy steels by radioactivation analysis. Manganese present in the steel sample is used as an internal standard, thus permitting accurate correction of neutron flux irregularities between sample and reference. The method was tested on 4 National Bureau of Standard samples having a vanadium content from 0.014 up to 2.04% and a widely differing composition as regards other alloy constituents. The results obtained by radioactivation in the Belgian Reactor BRI and the Amsterdam 28 MeV deuteron cyclotron show satisfactory accuracy as well as precision.     

Kinetic-spectrophotometric determination of trace amounts of vanadium(V) based on its catalytic effect on the reaction of DBM-arsenazo and potassium bromate

A simple and sensitive kinetic-spectrophotometric method is developed for the determination of trace vanadium(V), based on the catalytic effect of vanadium(V) on the oxidation of DBM-arsenazo by potassium bromate in 0.0138 moll(-1) phosphoric acid medium and at 100 degrees C in the presence of citric acid as activator. The absorbance is measured at 528 nm with the fixed-time method. The optimization of the operating conditions regarding concentrations of the reagents, temperature and interferences are also investigated. The working curve is linear over the concentration range 0-20 ngml(-1) of vanadium(V) with good precision and accuracy and the detection limit was down to 3.44 ngl(-1). The relative standard deviation for a standard solution of 14 ngml(-1) is 0.28% (n=11). The apparent activity energies of the catalytic reaction and the non-catalytic reaction are 73.48, 113.5 kJ/mol, respectively. The proposed method proved highly sensitive, selective and relatively rapid for the assay of vanadium at low-level range of 0-20 ngml(-1) without any pre-concentration step. Thw method was applied to the determination of vanadium(V) in steels, rice, flour, cabbage, potato, fish, shrimp and tea samples with satisfactory results. The obtained results for the steel samples were excellent agreement with the standard reference values. The analytical results of the rice, flour, cabbage, potato, fish, shrimp and tea samples were excellent agreement with those of atomic absorption spectrometry. The recovery experiments have been made for the rice, flour, cabbage, potato, fish, shrimp and tea samples except the steels; excellent results were obtained. The relative standard deviations were over the range of 0.18-2.60% and the recoveries were over the range of 98.00-102.4%, respectively. The analytical results obtained were satisfactory.     

430不锈钢热浸镀铝(硅)之铝化层成长研究

使用430不锈钢于680至800℃下作熔融铝硅合金热浸处理,研究热浸温度及热浸时间对铝硅合金化层成长的影响及铝化层之成长动力学.结果表明,430不锈钢在680~800℃经热浸16~289 s后,表面镀层与铝化层之生成厚度随热浸时间及热浸温度而增加,铝化层之成长动力学符合抛物线定律,并因相互扩散而形成FeA l3及Fe2A l5相,金相截面观察显示,680℃热浸处理的合金化层界面平坦,而在800℃下的即趋于不规则.     

Direct Determination of Vanadium in Water Samples,Human Hairs,Vegetables, and Foods by Graphite Furnace Atomic Absorption Spectroscopy

At present,the considerable attention was greatly paid to the determination of vanadium from the point of vanadium as a kind of biological nutrient element or one kind of industrial sources of pollution. In the paper,we employed graphite furnace AAS (GFAAS) method to determine directly the vanadium in samples, using optically controlled raising temperature combining with pyrolytic coating tube to atomize vanadium under the conditions of stable temperature for the determination of vanadium in samples.     

粉末电极伏安法测定高速钢中微量碳化物

金属电极伏安法可用于钢与合金的相分析，利用萃取残渣－金属型粉末电极提高了反应区活性相的浓度，从而提高了分析微量相的灵敏度和精密度。这种方法可用于高速钢中微量碳化物（ＭＣ）相的鉴定和定量分析。