Operation and Management of Electrical Equipment in Iron and Steel Enterprises

How to ensure the reliable operation of the complex and huge electrical system composed of a large number of electrical equipment in iron and steel enterprises?Combined with working experience,the author introduces four main factors affecting the normal operation of equipment,analyzes five main problems existing in the operation and management of electrical equipment,and puts forward corresponding improvement measures,so as to improve the management level of electrical equipment in iron and steel enterprises.

Discussion on Abnormal Corrosion and Material Selection of Hot Iron Ladles with Steel Scrap Addition

The abnormal corrosion of hot iron ladles was investigated.The performance,the composition and the structure of bricks for hot iron ladles were analyzed.The results show that(1)compared with the alumina-silicon carbide-carbon bricks for the ladle bottom,those for the ladle wall have more pyrophyllite and the Al2O3 content of 36.32 mass%;their bulk density,apparent porosity and cold compressive strength are lower than the requirement of industry standard;they have poor anti-oxidation performance and are oxidized to form a porous layer during service,which loosens the brick lining structure thus leading to fracture,local wear and structural damage of bricks;(2)without preheating,steel scraps are not completely melted,resulting in slag or steel attachment at the mouth or the bottom of ladles thus increasing damage of ladles;(3)and the residual bricks react with the attached slag to form low melting point phases affecting their hot properties.The refractories for the lining of hot iron ladles must be improved in combination with process changes,not entirely by raw materials replacement to reduce costs.

Current situation of carbon emissions and countermeasures in China's ironmaking industry

The iron and steel industry(ISI) involves high energy consumption and high pollution. ISI in China, a leading country in the ISI,consumed 15% of the country’s total energy and produced more than 50% of the global ISI’s carbon emissions. Therefore, in the context of global low-carbon economy and emission reduction requirements, low-carbon smelting technology in the ISI has attracted increasingly more attention in China. This review summarizes the current status of carbon emissions and energy consumption in China’s ISI and discusses the development status and prospects of low-carbon ironmaking technology. The main route to effectively reducing carbon emissions is to develop a gas-based direct reduction process and replace sintering with pelletizing, both of which focus on developing pelletizing technology. However,the challenge of pelletizing process development is to obtain high-quality iron concentrates. Consequently, the present paper also summarizes the development status of China’s mineral processing technology, including fine-grained mineral processing technology, magnetization roasting technology, and flotation collector application. This paper aims to provide a theoretical basis for the low-carbon development of China’s ISI in terms of a dressing–smelting combination.

Microstructure and properties of pure iron/copper composite cladding layers on carbon steel

In the present study, pure iron/copper composite metal cladding was deposited onto carbon steel by tungsten inert gas welding. The study focused on interfacial morphological, microstructural, and mechanical analyses of the composite cladding layers. Iron liquid–solid-phase zones were formed at copper/steel and iron interfaces because of the melting of the steel substrate and iron. Iron concentrated in the copper cladding layer was observed to exhibit belt, globule, and dendrite morphologies. The appearance of iron-rich globules indicated the occurrence of liquid phase separation（LPS） prior to solidification, and iron-rich dendrites crystallized without the occurrence of LPS. The maximum microhardness of the iron/steel interface was lower than that of the copper/steel interface because of the diffusion of elemental carbon. All samples fractured in the cladding layers. Because of a relatively lower strength of the copper layer, a short plateau region appeared when shear movement was from copper to iron.

On the Comparison of Microstructure Characteristics and Mechanical Properties of High Chromium White Iron with the Hadfield Austenitic Manganese Steel

In this study, high chromium white iron (HC-Wi) alloy and the Hadfield steel were studied. The microstructure of this high-chromium iron was studied using Metallurgical optical microscopy (OM) and compared to the Hadfield steel. The hardness and unnotched charpy impact strength of the HC-Wi alloy and Hadfield steel were examined at ambient temperature in the as-cast and heat-treated conditions. A pin-on-disc test at linear speed of 1.18 m/s and a 10 N normal load was employed to evaluate the wear behavior of both steel samples. Microstructural results showed that varying the carbon level in HC-Wi alloys can affect the chromium carbide morphology and its distribution in the austenite matrix which leads to considerable changes of the mechanical properties. Abrasion test showed that HC-Wi alloys have superior wear resistance, about three times of the Hadfield steel.

Steel Slag as an Iron Fertilizer for Corn Growth and Soil Improvement in a Pot Experiment

The feasibility of steel slag used as an iron fertilizer was studied in a pot experiment with corn. Slag alone or acidified slag was added to two Fe-deficient calcareous soils at different rates. Results showed that moderate rates (10 and 20 g kg-1) of slag or acidified slag substantially increased corn dry matter yield and Fe uptake. Application of steel slag increased the residual concentration of ammonium bicarbonate-diethylenetriamine pentaacetic acid (AB-DTPA) extractable Fe in the soils. The increase of extractable Fe was usually proportional to the application rate, and enhanced by the acidification of slag. Steel slag appeared to be a promising and inexpensive source of Fe to alleviate crop Fe chlorosis in Fe-deficient calcareous soils.

The Empirical Analysis of the Relationship between our Country Steel Price Index and the International Iron ore Freight Rate

The use of econometric methods to analyze the relationship between our country steel price index and the international iron ore freight rate,time series stationarity test,cointegration test,Granger test of causality and model parameter estimation tools use,find that there is Granger causality between our country steel price index and the international iron ore freight rate,China' s steel price fluctuations to some extent affect the international iron ore freight.

Evaluation of Corrosion Behaviour of Grey Cast Iron and Low Alloy Steel in Cocoa Liquor and Well Water

Corrosion behaviour of cast iron and low alloy steel in cocoa liquor and well water was investigated. The average weight losses of the specimens were measured using digital weighing balance. The results showed that the weight losses of both cast iron and low alloy steel in both media increases with time. Corrosion rate of cast iron in cocoa liquor increases rapidly with time for up to 336 hours (1000 μm/yr), but in well water the rapid rate of corrosion only lasted up to 187 hours (1160 μm/yr) thereafter it continuously dropping until 264 hours (667 μm/yr) after which it remains constant. Low alloy steel corroded faster in cocoa liquor up to 264 hours (200 μm/yr), whereas the initial rapid corrosion rate only lasted up to 168 hours (180 μm/yr) in well water environment. The results revealed that low alloy steel exhibited better corrosion resistance in both media, with cocoa liquor been more aggressive. Thus, low alloy steel will be a better material for piping and pumping system in cocoa processing industries.

Predictability of Hardness of the Heat Affect Zone in Aluminum Weldments Cooled in Palm Oil Based on Hardness of Similarly Cooled Mild Steel and Cast Iron Weldments

The predictability of hardness of the heat affected zone (HAZ) in aluminum weldments cooled in palm oil, based on hardness of similarly cooled mild steel and cast iron weldments has been ascertained. The general model: α = 1.2769? indicates that HAZ hardness of aluminium weldment is dependant on the ratio of product to sum of HAZ hardness of mild steel and cast iron weldments cooled in palm oil under the same conditions. The maximum deviations of the model-predicted HAZ hardness values α, μ and β from the corresponding experimental values αexp, μexp and βexp were less than 0.04% indicating the reliability and validity of the model.

Effects of Steel Fibers and Iron Filings on Thermal and Mechanical Properties of Concrete for Energy Storage Application

An experimental study on the thermal properties of iron filings and steel-fiber-reinforced concrete for solar/thermal energy storage application is presented in this report. It takes into account the results of measurements of thermal conductivity, thermal resistivity, thermal diffusivity and the results of compressive strength, density as well as energy storage capacity calculated from the knowledge of the above measured parameters. The experimental testing method is described as well: based upon the linear heat source theory, it requires the use of a special probe to be inserted into the sample. The experimentation was forwarded to test concrete aggregate mixtures with three different sizes and same quantity of steel fibers;two different quantities of iron filings and one plain concrete. The measurements were carried out from the pouring time of cubic samples and were ended up when hardened conditions were achieved. The results indicate that the steel fibers and iron filings have influence on the thermal and mechanical properties of the concretes tested, thus the iron filings and steel fibers reinforced concrete is suitable for better solar/thermal energy storage due to an increase in storage capacity over plain concrete.

Baotou Iron and Steel Company

The Baotou Iron and Steel Company(BISCO) is located at Baotou,830 kilometerswest of Beijing,in the Inner MongoliaAutonomous Region.The ore deposit atBaiyun’ebo,on which the company is based,was discovered by geologist DING Daohengin 1927 and was later found to be rich inrare earth elements.An extensive prospecting campaignwas launched after the founding of the

Study on the Corrosion inhibitor and Fog Suppressor for Chemical Pickling of Iron and Steel

A new type of corrosion inhibitor and fog suppressor composed of Nitrogen-containing alkaloid,water-soluble butadiene lower polymer, and inorganic electrolyte has been investigated by gravimetric and electrochemical method. Effects or this chemicals on pickling rate and hydrogen penetration into iron and steel material in 50～150 g/L HCI or/and H2SO4 solutions at 20～70℃ temperature were examined. The amount of acid fog escaping from the surface of air-liquid was determined by chemical titration. The results indicate that the efficiency of inhibition and suppression depends on film properties by which mean a barrier film on the interface of bare mild steel/solution or an unsolvable liquid membrane as hydrophibic effect.In present work the film-forming mechanism by in situ and chemistry-mechanics effect is also discussed.

NUMBER 3 RARE EARTH FACTORY OF BAOTOU IRON—STEEL AND RARE EARTH CORPORATION,FORGING AHEAD IN THE MARCH OF REFORM

The Baotou iron-Steel and Rare Earth Co. is located in Baotou of the AutonomousRegion of Inner Mongolia, where China has her largest mineral reserves of rare earths, par-ticularly that at Baiyunebo. The rare earth reserves in this region amount to as high as 80%of that of the whole Nation. The No. 3 Rare Earth Factory was established in 196l and itwas then a pilot plant of the Baotou Steel Works. In 1970 it was reconstructed as a formalplant. Now, it becomes one of the biggest rare earth production bases in China.

The Capital Iron and Steel Corporation's Fast Development of Exposer Trade

The Capital Iron and Steel Corporation (Shou Gang) is one of the eight major iron and steel companies in China and one of the first state-owned enterprises to be selected as a testing ground for the reform programme, since it was authorized to manage its own foreign trade in 1981, the Corporation’s export trade has expanded steadily. Especially since 1992, its development in foreign trade has skyrocketed because China Shou Gang International Trade Construction Company was approved to be set up. In 1993, it exported 239,700 tons of steel. Its foreign exchange income reached US$630 million, of which the Shou Gang’s self-managed exports took up US$96.98 million. During the

Characterization of Dissimilar Welding between 304 Stainless Steel and Gray Iron Using Nickel Coated Electrode

This paper presents the study carried out to study the microstructure and mechanical properties of AISI 304 stainless steel and gray iron, in order to recognize the effect of welding parameters on the joint. The shielded metal arc welding technique was applied with a 3.2 mm diameter nickel coated electrode under preheating and post heat conditions at 350°C. Vickers hardness test and metallographic analysis were carried out at the heat affected zone and at the interface to determine the effect on mechanical and metallurgical characteristics. Vickers hardness differences among joint areas were directly related to microstructural changes. There are no significant differences in AISI 304 hardness, but the hardness increased at the heat affected zone and decreased at the filler metal. Grey iron hardness at the heat affected zone was even lower and more slightly superior than grey iron hardness.

Corrosion and Electrochemical Behavior of 316L Stainless Steel in Sulfate-reducing and Iron-oxidizing Bacteria Solutions

Corrosion and electrochemical behavior of 316L stainless steel was investigated in the presence of aerobic iron-oxidizing bacteria IOB and anaerobic sulfate-reducing bacteria SRB isolated from cooling water systems in an oil refinery using electrochemical measurement, scanning electron microscopy SEM and energy dispersive atom X-ray analysisEDAX. The results show the corrosion potential and pitting potential of 316L stainless steel decrease distinctly in the presence of bacteria, in comparison with those observed in sterile medium under the same exposure time. SEM morphologies have shown that 316L stainless steel reveals no signs of pitting attack in the sterile medium. However, micrometer-scale corrosion pits were observed on 316L stainless steel sur- face in the presence of bacteria. The presence of SRB leads to higher corrosion rates than IOB. The interactions between the stainless steel surface, abiotic corrosion products, and bacterial cells and their metabolic products in- creased the corrosion damage degree of the passive film and accelerated pitting propagation.

Environmental boundary and formation mechanism of different types of H2S corrosion products on pipeline steel

To establish an adequate thermodynamic model for the mechanism of formation of hydrogen sulfide(H_2S) corrosion products,theoretical and experimental studies were combined in this work. The corrosion products of API X60 pipeline steel formed under different H_2S corrosion conditions were analyzed by scanning electron microscopy,energy-dispersive X-ray spectroscopy,and X-ray diffraction. A thermodynamic model was developed to clarify the environmental boundaries for the formation and transformation of different products. Presumably,a dividing line with a negative slope existed between mackinawite and pyrrhotite. Using experimental data presented in this study combined with previously published results,we validated the model to predict the formation of mackinawite and pyrrhotite on the basis of the laws of thermodynamics. The established relationship is expected to support the investigation of the H_2S corrosion mechanism in the oil and gas industry.

Highlights of Recent Advances in Refractories for Iron and Steel Industry in China

Recently procured outstanding achievements in iron and steel industry in China are presented by data or facts in steel output, energy consumption, technical and economical indicators and advanced technologies that are being adopted. The latest achievements in refractonries for this biggest user industry are reviewed, covering new refractories for CDQ coke oven, BF hearth, AOD Lining, long life tundish, SEN for clean steel making and regenerative reheating furnace . The reciprocal relationship is obvious that the rapid development of iron and steel industry has given an impetus to the advance of refractories industry, which in return has contributed greatly to the former.