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.

Energy Saving Analysis of Coal Gas Resource Utilization in Iron and Steel Enterprises

The article discusses the preparation of a gas balance sheet,as well as the recovery,storage,transporta-tion,and use of gas.An analysis was conducted on the occurrence and consumption quotas of various gas media,and specific energy-saving measures were elaborated for each process.This provides a theoretical reference for saving gas and reducing energy consumption in steel enterprises.

An Integrated Analysis on the Synergistic Reduction of Carbon and Pollution Emissions from China’s Iron and Steel Industry

Decarbonization and decontamination of the iron and steel industry(ISI),which contributes up to 15%to anthropogenic CO_(2) emissions(or carbon emissions)and significant proportions of air and water pollutant emissions in China,are challenged by the huge demand for steel.Carbon and pollutants often share common emission sources,indicating that emission reduction could be achieved synergistically.Here,we explored the inherent potential of measures to adjust feedstock composition and technological structure and to control the size of the ISI to achieve carbon emission reduction(CER)and pollution emission reduction(PER).We investigated five typical pollutants in this study,namely,petroleum hydrocarbon pollutants and chemical oxygen demand in wastewater,particulate matter,SO_(2),and NO_(x) in off gases,and examined synergies between CER and PER by employing cross elasticity for the period between 2022 and 2035.The results suggest that a reduction of 8.7%-11.7%in carbon emissions and 20%-31%in pollution emissions(except for particulate matter emissions)could be achieved by 2025 under a high steel scrap ratio(SSR)scenario.Here,the SSR and electric arc furnace(EAF)ratio serve critical roles in enhancing synergies between CER and PER(which vary with the type of pollutant).However,subject to a limited volume of steel scrap,a focused increase in the EAF ratio with neglection of the available supply of steel scrap to EAF facilities would lead to an increase carbon and pollution emissions.Although CER can be achieved through SSR and EAF ratio optimization,only when the crude steel production growth rate remains below 2.2%can these optimization measures maintain the emissions in 2030 at a similar level to that in 2021.Therefore,the synergistic effects between PER and CER should be considered when formulating a development route for the ISI in the future.

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.

Identification of the Credit Guarantee Network of Steel Trade Enterprises in China

The risk points in the credit guarantee network of steel trade enterprises were identified by using the network analysis method in this paper. Firstly, the formation and operation mechanism of steel trade credit guarantee network was analyzed.Secondly,a guarantee network was established to analyze the related network structure indexes based on the mutual guarantee data of 83 enterprises in a steel trade market. These indexes included centrality,honest broker,and structural hole. The results suggest that network analysis method can be used to find out the risk points of the guarantee network. Additionally,some recommendations are brought forth to reduce or prevent future crises.

Discussion on Gas Safety Protection Management in Steel Plants

The necessity of establishing gas protection station in iron and steel works is demonstrated,issues of strengthening the management of gas safety protection,studying new technology of gas protection,adapting to the needs of modernization and building large scale and intelligent iron and steel works are discussed.Relevant sug-gestions are also put forward.

Application of the Business Process Reengineering Model in Steel Enterprises

To satisfy the instancy requirements of resources integration inside and outside the enterprises for resolving the uniformity of information resources for steel enterprises in competing environment, a control model of ISPS-ERP system integration is proposed. The schemes based on regeneration of operation flow are designed here. The well effects are achieved during the implementing course in XG enterprise.

Does Environmental Regulation Weaken Industrial Competitiveness?Inspirations from China’s Iron and Steel Sector

China＇s economic growth is heavily influenced by exports, while reconciling environmental regulation and economic growth requires handling the relationship between environmental regulation and industrial competitiveness well. The effects of environmental regulation on industrial competitiveness are largely subject to the institutional design of environmental regulation. Despite numerous studies on the relationship between environmental regulation and industrial competitiveness, a consensus has yet to be reached. Aside from differences in research methodology, these studies failed to give sufficient consideration to the impact of environmental regulation on industrial competitiveness. Such effects can be negative or positive depending on the design of environmental regulatory policy. This paper has investigated the relationship between environmental regulation and the competitiveness of China＇s iron and steel industry and discovered that tighter environmental regulation does not diminish the competitiveness of the iron and steel industry since the policy design of environmental regulation accommodates the tolerance of advanced production capacity and includes a reasonable cost sharing mechanism. This discovery is of important reference for China to develop rational policy design to balance the relationship between environmental regulation and industrial competitiveness.

Impact of material and energy flow variation-based iron /steel ratio on production cost

This paper establishes a model for the production cost of iron and steel enterprise.The variation rule of the production cost versus the iron/steel ratio for two cases, namely,fixed steel production and a fixed amount of molten iron,is analyzed,and the concept of a steel scrap threshold price is proposed.According to the analysis results,when the steel scrap unit price exceeds the steel scrap threshold price, an increase in the iron/steel ratio can reduce the production cost,and vice versa.When the gap between the steel scrap unit price and the steel scrap threshold price is relatively large, the impact of the iron/steel ratio on the production cost is more prominent.According to the calculation example,when steel production is fixed （284 358 t/month）and the steel scrap unit price is 263.2 yuan/t more than the steel scrap threshold price,an increase of 0.01 in the iron/steel ratio causes a monthly production cost reduction of approximately 750 000 yuan （2.63 yuan/t）.When the amount of molten iron is fixed （270 425 t/month）and the steel scrap unit price is 140.7 yuan/t more than the threshold price,an increase of 0.01 in the iron/steel ratio causes a monthly production cost reduction of approximately 430 000 yuan （1.5 yuan/t）.The results indicate that iron and steel enterprise should adjust the production strategy in time when the scrap price fluctuates, and then the production cost will be reduced.

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.

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.

Some Aspects in the Development of High Performance Refractories for Iron and Steel Making in China

In the past 25 years in China, to meet with the rapid increase in steel production accompanied by adoption of advanced metallurgical technologies, there has been fast development of China＇ s refractories industry in production capacity, in quality improvement and in development of new products. Sophisticated high performance refractory materials mainly based on our rich reserves of magncsite, bauxite and flake graphite have been developed, such as carbon-bonded products, high purity oxide products, bauxite-based low creep and high strength high alumina bricks and LC, ULC and ZC castables. They have been used in blast furnaces, BOFs, EAFs, secondary refining and continuous casting with considerable improvement in service pecformance.

Centrifugal Casting of High Speed Steel/Nodular Cast Iron Compound Roll Collar

The centrifugal casting of compound HSS/nodular cast iron roll collar was studied,and the factors affecting transition zone quality were analyzed.The pouring temperature and interval in pouring are the main factors affecting transition zone quality.By controlling process parameter and flux adding during casting,high quality roll collar was obtained.The cause,why in the casting of HSS part,segregation appears easily,was analyzed and the countermeasure eliminating segregation was put forward,the measure eliminating heat treatment crackling was also put forward.

Optimization for vehicle scheduling in iron and steel works based on semi-trailer swap transport

In order to solve internal logistics problems of iron and steel works,such as low transportation efficiency of vehicles and high transportation cost,the production process and traditional transportation style of iron and steel works were introduced.The internal transport tasks of iron and steel works were grouped based on cluster analysis according to demand time of the transportation.An improved vehicle scheduling model of semi-trailer swap transport among loading nodes and unloading nodes in one task group was set up.The algorithm was designed to solve the vehicle routing problem with simultaneous pick-up and delivery(VRPSPD) problem based on semi-trailer swap transport.A solving program was written by MATLAB software and the method to figure out the optimal path of each grouping was obtained.The dropping and pulling transportation plan of the tractor was designed.And an example of semi-trailer swap transport in iron and steel works was given.The results indicate that semi-trailer swap transport can decrease the numbers of vehicles and drivers by 54.5% and 88.6% respectively compared with decentralized scheduling in iron and steel works,and the total distance traveled reduces by 43.5%.The semi-trailer swap transport can help the iron and steel works develop the production in intension.

Fabrication of plain carbon steel/high chromium white cast iron bimetal by a liquid–solid composite casting process

High-chromium white cast iron （HCWCI） is one of the most widely used engineering materials in the mining and cement industries. However, in some components, such as the pulverizer plates of ash mills, the poor machinability of HCWCI creates difficulties. The bimetal casting technique is a suitable method for improving the machinability of HCWCI by joining an easily machined layer of plain carbon steel （PCS） to its hard part. In this study, the possibility of PCS/HCWCI bimetal casting was investigated using sand casting. The investigation was conducted by optical and electron microscopy and non-destructive, impact toughness, and tensile tests. The hardness and chemical composition profiles on both sides of the interface were plotted in this study. The results indicated that a conventional and low-cost casting technique could be a reliable method for producing PCSYdCWCI bimetal. The interfacial microstructure comprised two distinct lay- ers： a very fine, partially spheroidized pearlite layer and a coarse full pearlite layer. Moreover, characterization of the microstructure revealed that the interface was free of defects.

Electrolytic surface hardening of steel, cast iron and aluminium-bronze

Electrolytic hardening process was developed in USSR in the 1950s. The process was developed but was not commercially exploited. There is no evidence of work done on this process in India. The author has done this original work applied to different materials like steel, cast iron and aluminum-bronze. This paper gives details of microstructural transformations along with hardness value achieved. There is vital scope for this process to become viable for surface hardening and selective hardening of small components.

RESEARCH ON THE APPLICATION OF RARE EARTHS IN IRON AND STEEL IN RECENT YEARS

China has the biggest rare earths resource in the world,no wonder she pays much at-tention to the application of rare earth metals (REM).The application of REM in iron andsteel in China began at the end of 1950’s.The production of REM-treated iron and steelhad been made steady progress in the period of 1980’s.The production of REM-treatediron and steel in 1989 was 1.4 million tons and 250,000 tons respectively.The interest oftreating steel with REM in China keeps growing even in these years,It comes from the nat-

Effects of sphere size on the microstructure and mechanical properties of ductile iron–steel hollow sphere syntactic foams

The effects of sphere size on the microstructural and mechanical properties of ductile iron–steel hollow sphere（DI–SHS） syntactic foams were investigated in this study. The SHSs were manufactured by fluidized-bed coating via the Fe-based commercial powder–binder suspension onto expanded polystyrene spheres（EPSs）. Afterwards, the DI–SHS syntactic foams were produced via a sand-mold casting process. The microstructures of specimens were investigated by optical microscopy, scanning electron microscopy（SEM）, and energy-dispersive X-ray spectroscopy（EDS）. The microscopic evaluations of specimens reveal distinct regions composed of the DI matrix, SHS shells, and compatible interface. As a result, the microstructures and graphite morphologies of the DI matrix depend on sphere size. When the sphere size decreases, the area fractions of cementite and graphite phases are observed to increase and decrease, respectively. Compression tests were subsequently conducted at ambient temperature on the DI–SHS syntactic foams. The results reveal that the compression behavior of the syntactic foams is enhanced with increasing sphere size. Furthermore, the compressed specimens demonstrate that microcracks start and grow from the interface region.

Application of BAIRD Photoelectric Spectrometer in Quantitative Analysis of Iron and Steel

BAIRD SPECTROVAC 2000(DV 5) consisting of new type of HR-400 high repeat rate spark spectrosource, air cooled sample stand and an annular purged tungsten counter electrode has been used continuously in the lab for many years and resulted in good economic benefits. The paper describes the application of the spectrometer in quantitative analysis of cast iron and steel products, and the experience and technique may be helpful to those who are using the same kind of instrument.