Iron Ingot Research Articles

Provenance of Iron Age iron in southern Germany: a new approach

Ores, slag, and blooms from an Early Iron Age smelting site in the Black Forest, southern Germany, were analysed in view of their possible provenance in combination with products from a modern smelting experiment. Rather than employing lead isotope ratios, like in a previous study, osmium and strontium isotope ratios are used for the discussion of provenance. The results of the smelting experiment with iron ores from the archaeological site and their comparison with original finds show the high potential of osmium as a tracer to determine provenance. Strontium may be an additional indicator but possible contaminations need to be assessed. A Celtic iron ingot has also been analysed to check the potential of osmium for further provenance studies.

Effect of alloying elements on thermal shock resistance of gray cast iron

The effect of some alloying elements on the thermal shock resistance of low alloyed gray cast iron was investigated. Alloying of molybdenum, chromium, nickel and tin to the gray cast iron ingot with specified composition was performed to identify optimum composition of alloyed gray cast irons for the best thermal shock resistance. Tensile and thermal shock tests were conducted to investigate the relationship between those two parameters. Scanning electron microscope was used to observe the morphology of cracks which were occurred during thermal shock tests on the surface of specimens. Eventually the results showed that the thermal shock resistance of the gray cast iron, containing (wt.%) 0.8 Mo, 0.2 Cr and 0.08 Sn of alloying elements was enormously increased in comparison with unalloyed and other low alloyed gray cast irons.

Iron content of Cambodian foods when prepared in cooking pots containing an iron ingot

To investigate the effect of cooking with an iron ingot on the iron content of several water and Cambodian food preparations. Various food and water samples were prepared, in replicate, in glass and aluminium pots with and without an iron ingot. The samples were subjected to iron content analysis using standard ICP-OES procedures. Prepared with an ingot, the iron content was 76.3 μg iron/g higher in lemon water, 32.6 μg iron/g higher in pork soup and 3.3 μg iron/g higher in fish soup, than in the same foods prepared without an ingot. Acidity of the food samples was positively associated with iron leaching. Even when taking into account the low bioavailability of contaminant iron, approximately 75% of the daily iron requirement can be met by consuming 1L of lemon water prepared with an iron ingot. Its use may be a cheap and sustainable means of improving iron intake for those with iron-deficient diets.

Iron-deficiency anaemia in rural Cambodia: community trial of a novel iron supplementation technique

More than 3.5 billion people are affected by iron-deficiency anaemia (IDA). Previous studies have shown that the use of iron pots in daily cooking ameliorates IDA. We report a study on the use of a novel treatment to address IDA in rural women in Cambodia, where the use of iron pots is not common. A community-wide randomized controlled trial was conducted in the village of Preak Ruessei, Kandal Province, Cambodia. Rural women (n = 189) were enrolled and randomly assigned by household to one of three groups: (i) control, (ii) iron treatment with no follow-up and (iii) iron treatment with follow-up visits to provide IDA education. Haemoglobin, serum iron and C-reactive protein concentrations were measured at baseline, 3 and 6 months. A reusable fish-shaped iron ingot was distributed to the two treatment groups and participants were directed to use them daily for cooking. We hypothesized that iron from the ingot would leach iron into food providing an effective iron source. Blood iron levels were higher in women in the iron fish plus follow-up at 3 months compared with controls, but this was not maintained. At 6 months, haemoglobin and serum iron had fallen in all groups and the proportion of anaemic women had increased. This study shows that the iron ingot was effective in the short but not longer-term against IDA. Though a novel treatment option, further research is warranted to determine bioavailability of leached iron and whether or not the surface area is large enough for sufficient iron leaching.

Mechanisms of long-term anaerobic corrosion of iron archaeological artefacts in seawater

An iron ingot immersed during 2000 years at 12 m depth in the sea has been examined with the help of a combination of microscale techniques. This methodology allowed us to show that the main phase precipitated during the immersion is an iron hydroxychloride (β-Fe 2(OH) 3Cl) that is characteristic of corrosion in anoxic and chlorinated medium. Moreover locally on the external part of the corrosion products sulphur containing phases have been identified as mackinawite (FeS) in nanocrystalline or slightly oxidised state. The presence of this phase could be explained by the activity of sulphate-reducing bacteria. The presence of β-Fe 2(OH) 3Cl could be interpreted via a thermodynamic modelling taking into account the environmental conditions.

マイクロ波加熱による砂鉄と木炭粉を利用した小鉄塊の生成

The fine iron ingot was developed by the microwave oven heating using the iron sand and the charcoal powder. In the initial stage in which the heating time was 3–6 min, the iron sand changed into the lump consisting of Fe, FeO, Fe2TiO4 and Fe2SiO4. By further increasing the heating time, the iron ingot with a smooth surface and a metallic luster was formed, since the fine Fe particles in the lump aggregated and the Fe particles separated from the other constituent phases. The yield on the iron ingot formed from the iron sand was almost 50 mass%, irrespective of the weight of the iron sand. It is also found that the microstructure in the fine iron ingot changed by the microwave heating time, from the cementite and the pearlite, through the graphite and the pearlite, to the cementite and the pearlite. This suggests that the carbon content in the fine iron ingot increased by the carburization, when the fine iron ingot was just formed. However, the carbon content decreased by the decarburizing reactions with increasing the heating time, since the charcoal powder decreased, and the contact with the charcoal powder was inhibited by the slag.

Ultra-Purification of Electrolytic Iron by Cold-Crucible Induction Melting and Induction-Heating Floating-Zone Melting in Ultra-High Vacuum

The effect of melting under ultra-high vacuum of 10−7 Pa on the purification of the high-purity electrolytic iron developed was investigated using a new cold-crucible induction melting furnace which was able to melt high-purity iron of 10 kg and a new induction-heating floating-zone melting furnace, which were designed and constructed using ultra-high vacuum technology. Ultra-high vacuum melting was quite useful even for the ultra-purification of iron 10 kg in weight. The high-purity electrolytic iron of 7.5 kg with residual resistivity ratio of 2000 to 2700 was melted using the cold-crucible induction melting furnace, and the pressure during melting after melt-down was kept from 1×10−6 to 8×10−7 Pa for 9 min. The 7.5 kg ultra-pure iron ingot of more than 99.9988 mass% purity after the chemical analysis of 33 elements, most of which were lower than each detection limit, was successfully obtained, even if this ingot contains their all elements of the detection limit value. Also the ultra-pure iron 35 g in weight of more than 99.9988 mass% purity was obtained from electrolytic iron of 99.996 mass% purity by the combination of cold-crucible induction melting in ultra-high vacuum and induction-heating floating-zone melting in UHV of 4×10−7 Pa after the analysis of 35 elements. The concentration of C+N+O+S decreases from 14.4 mass ppm before zone-leveling to 2.4 mass ppm after four zone-leveling passes in ultra-high vacuum. For further ultra-purification of iron it is absolutely necessary to develop and establish the trace analysis techniques of measuring accurately the concentration of non-metallic impurity elements at levels below 0.1 mass ppm and metallic impurity elements at levels below 0.01 or 0.001 mass ppm.

The application of thermal sprayed coatings for pig iron ingot molds

Molds made of gray cast iron for casting pig iron ingots are subjected to severe temperature fluctuations. The main life- limiting factor for mold damage is the formation of surface cracks arising from thermal fa-tigue. Various flame and plasma sprayed coatings were investigated to extend the life of these molds. Coating materials studied include plasma sprayed ceramic coatings with bond coats as well as flame sprayed oxidation- resistant alloy powders. The results of cyclic furnace tests from room temperature to 1100 °C in air, simulating the thermal cycle in casting, indicated that failure occurred along the interface between the bond coat and the gray iron substrate because of iron oxidation, and not at the interface between the ceramic top coat-ing and the bond coating for a superalloy substrate. The field test results indicated that plasma sprayed alumina coatings with 200 µm top coating thickness are the most promising materials for pig iron casting.

Thermal fracture endurance of cast irons with application study of pig iron ingot molds

Pig iron ingot molds manufactured with flake, compacted graphite cast iron, and spheroidal graphite cast iron were installed on a pig iron casting machine and subjected to thermal cycling for studying thermal fracture endurance of the three cast irons. The effects of graphite morphology on the fracture mechanism were analyzed by examining the fracture patterns, microstructures, and microcracks in the failed molds. The determining factors of thermal fracture endurance were elucidated with thermal fracture resistance indices. Compacted graphite cast iron exhibited better thermal fracture endurance than flake and spheroidal graphite cast irons because of its higher strength-to-thermal stress ratio.

Oxygen Content and Metallography of Atomized 304L Stainless Steel Powder

AbstractPure iron ingot, ferrochromium pellets, nickel balls, and silicon wafer were melted and refined in an induction furnace. The resultant 304L stainless steel melt was atomised into fine particulates by high pressure water jets. It was found that the oxygen content of the atomised steel powder could be controlled through the adjustment of the material and processing factors. The two major factors were the Si + Mn content of the melt and the method of addition of silicon wafer during melting. The thickness of the surface oxide layer and the internal oxygen content decreased with decreasing bulk oxygen content of the atomised 304L powder. The oxygen concentration in the interior was lower by a factor of 10–14 than that in the surface layer of the powder particles. The oxidation film formed on the surface of particles irrespective of the extent of oxidation of the atomised 304L powder. PM/0617

A study of the microstructures and properties of an A390.0 aluminium alloy produced by the layer deposition process

An A390.0 aluminium alloy produced by a newly developed layer deposition process was studied regarding the refinement of microstructures and the improvement of mechanical properties. The counterpart for comparison was the same alloy but cast in an iron ingot mould. The results show that silicon particles of the layer-deposited alloy are fine and uniformly distributed in the matrix. Moreover, the segregation is significantly inhibited. The silicon particles and segregation of the cast alloy are very coarse. The mechanical properties of the former also exhibit a better combination of strength and ductility. The excess dispersion strength from fine silicon particles is about 40 MPa which does not change with aging time to the first order. The ductility improvement is attributable to the fine silicon particles since they require higher strain for void nucleation. The coarsening rate of silicon particles is high for the layer-deposited alloy when homogenized at 495 °C. This is because of the high interfacial energy possessed by the fine distribution. The coarsening is an Ostwald ripening process controlled by volume diffusion.

Effective utilization of graphite blocks in the production of mold sleeves

For the purpose of increasing the coefficient of utilization of graphite sleeves, methods of rational cutting of a graphite block with a hollow drill are proposed. The relationships of the diameters of the graphite blank and the iron ingot are given.