Manganese In Iron Research Articles

Diffusion of manganese in iron obtained by dynamic hot pressing

The study indicates that in substitutional solid solutions with vacancy diffusion the diffusion mobility should be higher in materials produced by dynamic hot pressing.

Studies on the Distribution of Chromium, Manganese, Molybdenum and Vanadium in Hypoeutectic White Cast Iron

Studies on the Distribution of Chromium, Manganese, Molybdenum and Vanadium in Hypoeutectic White Cast Iron

The surface segregation behavior of manganese and nickel in iron

Electron probe micro-analysis and an electrolytic sectioning technique have been used to study the surface segregation of manganese and nickel in Fe-1% Mn, Fe-1% Ni and Fe-1% Mn-1% Ni alloys during annealing in the temperature range 260–760°C. Annealing at and above 590°C causes Mn, but not Ni, to segregate into an enriched surface zone typically 1–2 μm thick underlain by an Mn-depleted zone. The characteristics of the segregation are consistent with a non-equilibrium segregation model which predicts that when solute-vacancy binding energy is low and solute diffusivity is higher than solvent diffusivity, then solute enrichment occurs in the vicinity of vacancy sources. In the case of these alloys it is believed that during annealing in the temperature range where FeO is the predominant oxide, the occurrence of oxidation creates a vacancy flux inward from the surface, thereby allowing high diffusivity solute such as Mn to segregate to the surface. Since Ni diffusion occurs at about the same rate as does Fe self-diffusion, the surface segregation of Ni does not occur.

溶鉄中のクロム，マンガンおよびニッケルの拡散

溶鉄中のクロム，マンガンおよびニッケルの拡散

The surface segregation behaviour of manganese and nickel in iron

The surface segregation behaviour of manganese and nickel in iron

Mechanisms of Trace Metal Transport in Rivers

Trace metals transported by the Amazon (and Yukon rivers were analytically partitioned among the transport phases: in solutions, ion exchange, organic materials, metallic coatings, and crystalline solids. The distribution for both rivers is similarly proportioned, with copper and chromium transported mainly in the crystalline solids, manganese in coatings, and iron, nickel, and cobalt distributed equally between precipitated metallic coatings and crystalline solids.

Diffusion of manganese in paramagnetic BCC iron

Diffusion of manganese in paramagnetic BCC iron

Removal of graphite by oxidation with perchloric acid plus periodic acid: Inapplicability to the spectrophotometric determination of manganese in steel

An attempt has been made to improve the Willard and Greathouse periodate method for the determination of manganese in high-carbon steel and cast iron by oxidizing the graphite with periodic acid in the presence of perchloric acid and phosphoric acid. Graphite is rapidly oxidized at 150° by this mixture but manganese is lost by volatilization as the heptoxide and decomposition of the latter on hot surfaces to manganese dioxide. No way was found for either the quantitative removal and recovery of manganese by volatilization or for quantitative return to the main solution. The spectrophotometric determination of manganese in the supernatant liquid after allowing graphite to settle yields imprecise but not wholly unacceptable results; for the highest accuracy, graphite should be removed along with silica following dehydration of the latter with perchloric acid.

Determination of microquantities of manganese in iron, steel and some non-ferrous metals by extraction and absorption photometry

The photometric determination of manganese described is based on the oxidation of the Mn to permanganate by means of persulphate, reaction with tetraphenylarsonium chloride, extraction of the complex with dichloroethane from 0.7 N sulphuric acid solution and measurement of the absorption of the extract at 528 nm. Manganese can be determined in the ppm-range in iron, steel, nickel, copper, aluminium and magnesium. Interferences are caused by larger concentrations of chromium.

炭素飽和溶鉄中のクローム.マンガンおよびニッケルの拡散

炭素飽和溶鉄中のクローム.マンガンおよびニッケルの拡散

Fe-O-J系およびFe-S-J系溶鉄の窒素吸収速度

The rates of nitrogen absorption in the ternary liquid iron, Fe-O-J, at several oxygen levels were measured at 1600°C. The results show that chromium and vanadium clearly increase the apparent mass transfer coefficient in any oxygen levels, as chromium and vanadium increase up to about 2%. Manganese and nickel have virtually no effect on the apparent mass transfer coefficient. The deoxidizing elements, such as chromium and vanadium, act as counter-poison for surface active oxygen. However, it is reasonable to consider that oxygen at the gas-metal interface mostly remains near interface, andacts as a resistant substance, even if the deoxidizing elements are present.It is further observed that carbon, manganese and silicon in the ternary liquid iron, Fe-S-J, have virtually no effect on the apparent mass transfer coefficient, probably because of the lower affinities of these elements to sulphur and the weaker effect of sulphur on the rate of nitrogen absorption than oxygen.

A microscopic and electron probe investigation of manganese nodules from the northwest Indian Ocean

Microscopic and electron probe examination of some manganese nodules show that they consist of segregations of manganese-iron oxides in an interstitial material almost free of manganese but rich in iron and silicates. The segregations are widely spaced in the volcanic cores of the nodules but become more abundant towards their outer crusts where they form the centres of linked polygons of interstitial materials. Most of the minor elements are concentrated in the segregations compared to the interstitial materials.It is suggested that the structures observed result partly from solution and reprecipitation of elements in the original volcanic cores of the nodules and partly from the replacement and coating of these cores by manganese-iron oxides precipitated from sea water.

Spectrophotometric determination of small amount of manganese in iron and steel and in pure iron.

A simple and accurate spectrophotometric method for the determination of 0.00010.1% of manganese in iron and steel and in pure iron with sodium periodate has been established as follows. The sample (0.5 to 1g) is decomposed by treatment with a mixture of sulfuric, phosphoric, and nitric acids, 25 ml of sodium periodate solution (0.5 w/v%) is added, and the solution is heated for 45 min. on a hot plate. After cooling, 3 ml of urea solution (50 w/v%) is added, and the mixture is made up exactly to 50 ml with water. The absorbance is measured at 530 mμ against water. One or two drops of sodium nitrite solution (10 w/v%) are then added with through mixing, and the absorbance is measured again. In case of less than 0.001% of manganese, 5 g of sample is decomposed with perchloric acid, and after cooling, interfering elements are removed by extraction with methyl-isobutyl ketone (MIBK) from 7N hydrochloric acid solution containing perchloric acid. The time required for an analysis is abount 15min. (The MIBK extraction method requires about 50 min.).

Determination of microamounts of manganese in iron, steel and aluminum by square wave polarography

トリエタノールアミン-水酸化ナトリウム支持塩を用いるく形波ポーラログラフ法による鉄鋼とアルミニウム中の微量マンガンの定量法について検討した.試料は過塩素酸に溶解後, トリエタノールアミンおよび水酸化ナトリウムを加え室温で約25分空気を吹き込みマンガンを酸化し, ポーラログラフ測定を行なう迅速法である.銅およびコバルトの約25倍量の共存は問題ない.定量下限は, 鉄鋼中のマンガンでは0.001%で, アルミニウム中のマンガンは0.002%である.

介在物の組成変化についで

After the equilibrium between molten iron and the systems FeO-MnO-SiO2 and FeO-MnO-CrO-SiO2 was established in the silica crucible at 1650°C, the temperature was lowered rapidly to 1550°C and this temperature maintained till the equilibrium was attained again. The variations of the concentration of the components in the liquid iron and slag were measured. The results obtained are summarized as follows:1) MnO and FeO were reduced in the system FeO-MnO-SiO2 slag by the excess silicon due to the lowering temperature at more than 0⋅18%, manganese in the liquid iron. The relation between reduction ratio of MnO and the concentration of silica was estimated. Up to 0⋅18% manganese, this excess silicon, however, was not sufficient to deoxidize, MnO was not reduced in this case.2) FeO, MnO and CrO were reduced in the system FeO-MnO-CrO-SiO2 slag by the excess silicon same as the system FeO-MnO-SiO2 in the case of 5%Cr. But in cases of 9% and 14% Cr, the reduction of these oxides did not occur. It was considered that the new phase was formed at the boundary of both phases.3) It was anticipated from the experimental results obtained above that the equilibrium between inclusion and molten iron was established fast. The mechanism of the formation of oxide inclusions composed of FeO-MnO-SiO2 system were examined experimentally by addition of deoxidizers. The results showed that if the processes of formation of oxide inclusions composed of FeO-MnO-SiO2 system were examined experimentally by addition of deoxidizers. The results showed that if the processes of formation of inclusions could be known, based on the equilibrium data, the components of inclusion could be evaluated from the concentration of dissolved elements in the liquid iron.

DIRECT ELECTRIC-FIELD ELECTROTRANSPORT OF CARBON AND NITROGEN IN IRON AND IRON ALLOYS

The interstitial mobility of carbon and nitrogen in austenite iron is determined from diffusion experiments carried out in a direct electric field. Diffusion-penetration curves are obtained, using a microhardness technique, and related to the "apparent charge" of the solutes by the Einstein equation. The apparent charge of carbon is positive, increasing from +8.6 ± 1.0 at 950 °C to +13.7 ± 1.7 at 842 °C. The apparent charge of nitrogen is negative, increasing from −8.3 ± 1.0 at 1 000 °C to −14.1 ± 1.7 at 922 °C. Positive Hall coefficients are found for both systems at 925 °C. The effect of 4% manganese in iron is to increase the apparent charge of carbon to ~ +9.3, while 2% silicon in iron decreases the apparent charge of carbon to ~ +4.7 at 950 °C. The results obtained are discussed in relation to the band structure of the alloys and the effect of electron or "hole" momentum transfer to the lattice. A possible alternative mechanism is also proposed which could contribute to the high apparent charge obtained for the solutes.

CO2-O2アーク溶接法による鋼材溶接部の衝撃値(第1報)

A rimmed steel (0.20% C, 0.01% Si, 0.49% Mn) was welded using CO2-O2 arc welding process with eight electrode wires. The silicon and manganese contents in each electrode wire were varied (0.33-1.26% Si, 1.44-0.90% Mn, respectly). Effects of chemical compositions of electrode wires and oxygen contents in supplied gas on V-notch Charpy impact values of weld metals were investigated and the following results were obtained:(1) Impact values of weld metals are generally increased with addition of oxygen to supplied gas, if electrode wires contain sufficient amounts of silicon and manganese.(2) Impact values of weld metals are high when silicon and manganese of electrode wires are contained in the field in which unsaturated silicate is produced by deoxidizing reaction with silicon and manganese in molten iron. But if electrode wires contain large amounts of non-metallic inclusions, the values are not always high, though their silicon and manganese contents may be the same as the above mentioned.(3) Therefore it is necessary to minimize the amounts of non-metallic inclusions of electrode wires as much as possible to increase the impact values of weld metals.

Thermodynamic functions of an FeMn solid solution formed by the Fe(n, p)Mn reaction

A dilute solution ( x u = 3 × 10 −6) of manganese in iron was formed by neutron irradiation of natural iron Fe 54(n, p)Mn 54 and by means of the Knudsen effusion technique the quantity p u x u , where p u is the partial pressure of manganese, was estimated for temperatures between 1073°K and 1673°K. The Raoultian activity coefficient was 0.3 and the variation with temperature was small corresponding to a partial heat of solution of 1.25 kcal/g-atom, (even though the cohesion energy of manganese is 33 kcal/g-atom less than that of iron). The value 0.3 arises from the positive excess entropy of solution. It is suggested that this excess entropy is primarily due to changes of the electronic specific heat of solution rather than changes in the lattice vibrations.

A Method of Activation Analysis for Competing Reactions by Using Reactor Neutron Spectra (Activation Analysis of Manganese in Iron)

原子炉を用いて放射化分析を行なうさいに, しばしば競合反応による妨害が問題になる。たとえば, Fe中のMnを放射化分析で測定するには55Mn (n, γ) 56Mn反応を利用するが, 一方, 56Fe (n.p) 56Mn反応でも56Mnが生成する。したがって, これらの両者の生成割合を知ることが必要になる。これらの生成割合は照射設備の中性子スペクトルに依存する。われわれは原子炉を放射化分析に利用する場合に, このような競合反応の生成割合を測定する一方法を導き, その実際的な有用さを, Fe中の不純物Mnの測定について, HTRを用いて確かめた。本方法の精度, 検出感度についても検討を行なった。本方法はカドミウム比のみを測定すればよいので測定が簡便である。また, 競合反応の生成量が正確に測定できるので炉心近傍の高い中性子束密度の積極的な利用が可能である。

The determination of manganese in iron and steel by atomic absorption spectrophotometry

A procedure is described for the determination of 0.001–2% of manganese in low and high alloy irons and steels by atomic absorption spertrophotometry. The sample is dissolved in phosphoric-sulphuric acid and atomised in an atomic absorption spectrophotometer. The method is rapid, free from interferences, preliminary separations are not required and results obtained on standard samples agree closely with stated certificate values.