Steel Production Technology Research Articles

Product innovations of key economic importance for the steel industry

Steel and materials in general entertain a special connection with time and therefore with innovation. Indeed, steel has been around for more than 4 millennia and is still innovating, which demonstrates both a status of socio-economic invariance and a cumulative innovation process, which deeply differs from the status of the “high-tech” consumer products, which are considered today as highly innovative. This is a complex situation, which is best described by telling various narratives from the standpoint of history, innovation management, sustainability, economy and business, with both long and short times perspectives. The Historian’s perspective insists on slow time, especially as regards innovation, in which steel took part. Steel and steel production technology have thus accompanied society in its long journey through time since the Neolithic, Roman and Celtic times, the Middle Ages, Modern Times and Industrial Revolutions. Today, the technological episteme seems to be frozen in a stasis that has been rolling out global steelmills across the world and most recently in China. The present technological paradigm was built under the pull of the social and economic drivers which have led to the geopolitical world as it is today. Innovation today, continues, but not visibly at the level of process engineering, but regarding metallurgy and material science, thus exploring the deep connection of steels with specific and always changing applications. Regarding process engineering, however, the on-going economic transitions, i.e. the energy, ecology and digitization transitions, may awaken Sleeping Beauty’s castle and relaunch a new series of paradigm shifts in making steel. Low-carbon technologies are being explored to meet the Climate Change challenge, which may rekindle the sustainability innovation driver. And a reexamination of the scale at which steel is made might possibly stem from Additive Manufacturing, although this is still a weak signal as far as steel is concerned.

Elaboration of the Thermodynamic Model of Refining the Converter Bath when Blowing through Three-Tier Oxygen Lance

Background. In modern conditions, the BOP-process is the main method of mass use steel product production. At the same time, due to the shortage of high-quality charge materials, resource and energy-saving technologies are particularly relevant. To optimize the BOP-process under modern conditions, it is promising to use improved oxygen lances for top blowing in comparison with known designs.Objective. An important stage in the development of advanced steel production technologies is obtaining information on the thermodynamic model of blowing a converter bath through a three-tier lance with the elaboration of the regularities of oxidation processes within the reaction zone of a 160-ton industrial converter.Methods. The analysis that was carried out has a theoretical nature and is based on the definition of the influence of temperature and pressure on the regularities of oxidation processes within the reaction zones formed when oxygen jets are introduced into the volume of a metal bath, foamed slag-metallic emulsion and waste gases in the working space of the converter. As a thermodynamic parameter, the Gibbs energy was used to estimate the probability of chemical reactions. The pressure effect on the oxidation processes in the converter bath was evaluated in accordance with the Van’t Hoff formula.Results. The thermodynamic features of oxidation processes in the 160-ton BOF bath using a three-tier lance are presented. Primary reaction zone is characterized by the occurrence of oxidation of manganese, silicon, carbon, and iron by gaseous oxygen. In the secondary reaction zone there are chemical reactions of the oxidation of silicon and carbon dissolved in the metal by oxygen, as well as the reduction of iron oxide by carbon. The presence or absence of a slag phase on the melt surface practically does not affect the occurrence probability of chemical transformations within the boundary of primary and secondary reaction zones. The additional secondary oxygen jets are characterized by oxidation of the oxide components of the slag and gas phases.Conclusions. During the research it was clarified the thermodynamical model of the oxidation processes in primary and secondary reaction zones, that were formed due to the interaction of 160-ton BOF bath with the supersonic and sonic oxygen jets flowing out of the separate groups of nozzles (of Laval and cylindrical shapes) of top three-level oxygen lance.

Improving the Rolling Technology at Mill 450 OJSC "MMK" to Reduce the Level of Alloying of 09G2S Steel Designed for Strength Class up to 440 MPa

Nowadays, the technology of shape-rolled steel production defines the quality and strength of common purpose and critical building structures. To provide for all the necessary mechanical characteristics, it is necessary to pay attention to each phase of steel production: melting, casting, reheating, rolling and cooling. Often, due to poor production equipment and lack of appropriate technologies steel alloying is applied. This deteriorates steel weldability and significantly increases the cost of the rolled product. The article reviews the final stage properties formation – water quenching stage after the rolling mill. Now, at mill 450 of OJSC Magnitogorsk Iron and Steel Works (MMK) vanadium is used for microalloying during the production from 09G2S steel, which provides for the specified technical properties of steel. The developed quenching technology provides for a possibility to decrease the level of microalloying. The following mathematical simulation was carried-out: steel section cooling down during quenching; heat treatment of section steel using DEFORM 3D + Heat Treatment software and further physical simulation to define convective heat transfer temperature coefficients, find tendencies to hardening and dynamics analysis which made it possible to develop a three section module located after dividing shears consisting of 176 nozzles (44 nozzle blocks). As for the proposed design of water cooling line, regimes which provides strength classes 345, 390 and 440 MPa are developed for L-steel with sizes from 40x40x4 to 125x125x16 mm, channel steel from 50 to 180 mm web length and strip (of equivalent thickness).

Production of continuous-cast pipe blank without large nonmetallic inclusions

The quality of metal in continuous-cast pipe blanks is investigated, for different steel-production technologies. The presence of large nonmetallic inclusions is largely due to disruptions in the continuouscasting technology. Other significant factors are nonoptimal modification of the nonmetallic inclusions and problems in ladle treatment. Measures ensuring acceptable content of nonmetallic inclusions are developed and tested.

On the Aqueous Recovery of Zinc from Dust and Slags of the Iron and Steel Production Technologies

Recently the iron and steel makers as well are much more concerned with the by-products and waste streams generated in their ferrous metallurgical industries. In general, the relevant minor or trace elements (Si, Mn, P, Al, S, As, Cu, Zn, K, Na, Ti, Cr, V, W etc.) are not concentrated very much in the different slags and dust produced and collected during the subsequent processing steps of iron and steelmaking. However, zinc can be an exception, especially when zinc containing (e.g. hot dip galvanized) steel scraps are recycled in electric arc furnaces (EAF) to produce new unalloyed steels.

The modern technology of iron and steel production and possible ways of their development

In the changing global market scenario for raw materials for the steel industry, a number of novel ironand steelmaking process technologies are being developed to provide the steel companies with economically-sustainable alternatives for ironand steel-making. In addition, the steel industry is also focusing on reduction of energy consumption as well as green-house gas (GHG) emissions to address the crucial subject of climate change. Climate change is presenting new risks to the highly energyand carbon-intensive, iron and steel industry. The industry needs to focus on reduction of energy consumption as GHG emissions to address climate change. Development of alternate ironand steelmaking process technologies can provide steel companies with economically-sustainable alternatives for steel production. For managing climate change risks, novel modeling tools have been developed by Hatch to quantify and qualify potential energy savings and CO2 abatement within the iron and steel industry. The tool developed for abatement of greenhouse gas carbon is called G-CAPTM (Green-House Gas Carbon Abatement Process) while that developed for improving energy efficiency is called En-MAPTM (Energy Management Action Planning). Evaluation of existing operations have shown that most integrated plants have GHG and energy abatement opportunities; on the other hand, the best-in-class plants may not have a lot of low-risk abatement opportunities left, even at high CO2 price. In this context, it is important to assess these critical issues for the alternate ironand steelmaking technologies that have been developed. This paper presents a comparative evaluation of energy-efficiency and GHG emissions for some selected ironand steelmaking technologies that are being considered for implementation. In this work, Hatch’s G-CAP™ and En-MAP™ tools that were developed with the main objective of quantifying and qualifying the potential energy savings and CO2 abatement within the iron and steel industry, were employed in the evaluation conducted.

Thermophysical characterization of a by-product from the steel industry to be used as a sustainable and low-cost thermal energy storage material

In the metallurgical industry, large amounts of waste called slag are accumulated besides the production of iron and steel. One part, considered as by-product, is recycled but the other part, considered as waste, is still landfilled with potential bad consequences for environment. In this paper, two electric arc furnace slag samples (most common steel production technology in Europe), have been considered and characterized to be used in medium and high temperature thermal energy storage systems. These slags have demonstrated relevant properties to store thermal energy by sensible heat from ambient temperature up to 1000 °C, and their representativeness of the worldwide produced slag in a wide EAF (electric arc furnace) steelmaking process range. The objective is to develop sustainable and low-cost thermal energy storage systems for industry waste heat recovery and in renewable energy applications. At the same time, this new valuable market for slag in the energy field could solve a big part of the waste management problem in the iron and steel sector.

Production of flat electrical steel with superlow magnetic losses

The influence of the chemical composition of steel (its Al, Si, and Sb content) on its texture and magnetic properties is studied, with a view to developing a production technology for high-alloy isotropic electrical steel (containing up to 3% Si) with superlow magnetic losses (P1.5/50 ≤ 2.70 W/kg for strip of rated thickness 0.50 mm and P1.5/50 ≤ 2.50 W/kg for rated thickness 0.35 mm) and a high degree of flatness (nonplanarity class 1 according to State Standard GOST 21427.2, with discrepancies no greater than 2 mm). Alloying with aluminum and antimony improves the texture of the final steel and hence greatly reduces the magnetic losses. The influence of cold rolling and recrystallization annealing of the flatness of the final strip is discussed.

Production technology for arctic pipeline and marine steel

Production technology for cold-resistant pipelines and marine steel that may be used in the Arctic and the Far North is discussed.

Techno-economic evaluation of innovative steel production technologies

At current primary steel production levels, the iron and steel industry will fail to meet the 80% emission reduction target without introduction of breakthrough technologies (Wortler et al., 2013: 19). The current research analyses the technical and economical long-term potential of innovative primary steel production technologies in Germany throughout 2100. Techno-economic models are used to simulate three innovative ore-based steelmaking routes verses the reference blast furnace route (BF-BOF). The innovative routes in focus are blast furnace with CCS (BF-CCS), hydrogen direct reduction (H-DR), and iron ore electrolysis (EW). Energy and mass flows for the production of one tonne of crude steel (CS) are combined with hypothetical price, cost, and revenue data to evaluate the production routes economically, technically, and environmentally. This is a purely theoretical analysis and hence further external factors that may influence practical implementation or profitability are not considered. Different future developments are considered by using three scenarios, representing an ambitious, a moderate, and a conservative transformation of the German energy sector. In general, looking into the future bares various uncertainties which should be reflected in a suitable manner. According to the present scenario analysis, chances are that with rising prices for coal and CO2 allowances BF-BOF and even BF-CCS become unprofitable by mid-century. With a high share of renewable energy sources and high prices for CO2 allowances, H-DR and EW become economically attractive in the second half of the current century, when BF-based routes are long unprofitable. Energy and raw material efficiency is significantly higher for H-DR and EW and furthermore, the 80% reduction target by 2050 can be achieved in the ambitious scenario. However, high investment costs and high dependency on electricity prices prohibit a profitable implementation before 2030–2040 without further subsidies. EW is the most energy and resource efficient production route. Since continuous electricity is needed for the continuous operation, the electricity costs are 20–40% higher than for H-DR (with high-capacity hydrogen storage units). Even though hydrogen production implies efficiency losses compared to the EW route, the decoupling of hydrogen production from continuous operation of the steel plant through hydrogen storage offers the opportunity to use cheap excess renewable electricity. This makes the H-DR economically and environmentally the most attractive route and provides a crucial contribution to stabilize the grid and to store excess energy in a 100% renewable energy system.

The impact of climate targets on future steel production – an analysis based on a global energy system model

This paper addresses how a global climate target may influence iron and steel production technology deployment and scrap use. A global energy system model, ETSAP-TIAM, was used and a Scrap Availability Assessment Model (SAAM) was developed to analyse the relation between steel demand, recycling and the availability of scrap and their implications for steel production technology choices. Steel production using recycled materials has a continuous growth and is likely to be a major route for steel production in the long run. However, as the global average of in-use steel stock increases up to the current average stock of the industrialised economies, global steel demand keeps growing and stagnates only after 2050. Due to high steel demand levels and scarcity of scrap, more than 50% of the steel production in 2050 will still have to come from virgin materials. Hydrogen-based steel production could become a major technology option for production from virgin materials, particularly in a scenario where Carbon Capture and Storage (CCS) is not available. Imposing a binding climate target will shift the crude steel price to approximately 500 USD per tonne in the year 2050, provided that CCS is available. However, the increased prices are induced by CO2 prices rather than inflated production costs. It is concluded that a global climate target is not likely to influence the use of scrap, whereas it shall have an impact on the price of scrap. Finally, the results indicate that energy efficiency improvements of current processes will only be sufficient to meet the climate target in combination with CCS. New innovative techniques with lower climate impact will be vital for mitigating climate change.

Optimization of Mechanical Properties of Low Carbon Bainitic Steel Using TMCP and Accelerated Cooling

The recent increased severity in service conditions, such as frequent earthquakes, have further promoted the development of steel production technologies for many types of microstructural control. In the present paper, two-stage thermomechanical control process (TMCP) combined with accelerated cooling was employed to control the microstructural evolution and to study the microstructure-property relationship of low carbon bainitic steel. The main microstructure of hot rolled steel plates changed from granular bainite to lath bainite (or bainitic ferrite) when the final accelerated cooling temperature decreased from about 530 to 430°C, accompanied with a notable increase in yield strength at the expense of slightly decreasing toughness. The strengthening mechanism was mainly attributed to dislocation strengthening and precipitation strengthening for this low carbon microalloyed steel. In addition, if the strain hardening exponent of hot rolled steel plate with the thickness of 13mm is expected to be higher than 0.1, the final cooling temperature range should be maintained above 500°C.

Switching to carbon-free production processes: Implications for carbon leakage and border carbon adjustment

Climate policy under partial global compliance raises concerns regarding carbon leakage. While border carbon adjustment (BCA) measures are a potential remedy, they have also been criticised on various grounds. This paper therefore investigates whether a policy fostering the switch to carbon-free technologies can substitute for BCAs. A reason for the effectiveness of a targeted technology policy is that major leakage prone sectors (such as iron and steel), have two main sources of carbon emissions, combustion of fossil fuels and industrial processes. While combustion emissions can be reduced relatively easy by increasing energy efficiency, reducing process emissions requires a switch to low-carbon production processes, e.g. in steel production by deploying electrolysis based on large-scale solar electricity. We show by means of a multi-regional computable general equilibrium analysis that such a switch in steel production technology can eliminate a significant fraction of carbon leakage and also increase sectoral output and welfare. Since the necessary technologies are not available at large scale yet (however, are likely to be by 2020), a transitional BCA scheme may be a crucial supportive instrument to foster such technology switches. Yet, in the long run BCA should be phased out to preserve the incentive for carbon-free innovation.

Production of continuous-cast slabs from low-silicon steel

At OAO Chelyabinskii Metallurgicheskii Kombinat, a production technology for high-quality, low-carbon, and low-silicon steel capable of deep extrusion (08У, 18УA, 08πc and similar steel) has been developed and introduced. Continuous-cast slabs are produced by means of the following system: an arc furnace, a ladle-furnace unit, and a continuous-casting machine. Appropriate engineering measured for the production of such steel slabs have been developed.

Improving rail-steel production

A new production technology for vacuum-treated rail steel has been developed, with reduced carbon content (0.10%) at discharge from the furnace and the addition of carbon-bearing materials on ladle intake. This technology reduces the total oxygen content of the steel and the content of brittle-fracturing oxide inclusions in the rail, without impairing the physicomechanical properties.

Developing bearing steels combining hydrogen resistance and improved hardness

Thermodynamic and kinetic computational modelling are combined to conceive a hydrogen resistant bearing steel. Existing hydrogen resistant steels are not appropriate for bearings due to their low hardness. The proposed microstructure combines a martensitic matrix in which fine cementite precipitates impart strength, and V4C3 nano-scaled particles acting as hydrogen traps. It is demonstrated that the conflicting objectives of ultra-hardness and hydrogen resistance can be concealed by: (1) Adding 0.5wt.% V to 100Cr6, which allows to preserve existing steel production technology. (2) Following a novel heat treatment procedure consisting of austenitisation (and a subsequent temperature spike to dissolve coarse V4C3), followed by tempering at 600°C where V4C3 particles form (and a subsequent temperature spike to dissolve coarse cementite), followed by quench and tempering at 215°C, where fine cementite strengthening particles form. The enhanced trapping capacity of the new steel is demonstrated via thermal desorption; the presence of the desired microstructure after heat treatment is proved via transmission electron microscopy. Concomitant with the trapping ability, a significant hardness increase was observed; this was ascribed to the controlled V4C3 precipitation.

New Sophisticated Analysis Method of Crystallizer Temperature Profile Utilizing Optical Fiber DTS Based on the Stimulated Raman Scattering

Continuous casting is a modern and advanced technology of steel production, whose product is a steel blank as a semifinished product for further manufacturing. It is known that better monitoring and process control of casting improves the steel quality and is able to ensure customers’ requirements in terms of sizes, brands, quantities and properties with lower costs. The crystallizer belongs among the most important parts of this whole process [1]. At present many methods for analysing of the crystallizer temperature profile in operation were published and experimentally verified. In these methods, the thermocouples or Bragg gratings are widely used. New sophisticated analysis method of crystallizer temperature profile is the utilization of the optical fiber DTS based on the stimulated Raman scattering. This paper describes the first experimental measurement and verification of the method, which are necessary for the method deployment into the industrial practices.

The evolution of large-truss road bridges in NSW, Australia

This paper describes the evolution of large-truss road bridges in New South Wales (NSW), Australia, citing specific examples of various genres. In particular, the high proportion of iron bridges constructed in northern NSW over approximately a 25-year period from around 1870 is highlighted. The proportion here was greater than the rest of NSW for the same period. Various postulates are canvassed as to why that might have been so. With the onset of periods of financial astringency, the engineering profession had to adapt and make changes to take account of worsening economic conditions and political imperatives of the times. Typical of such major changes at the time was a dramatic swing from substantive iron road bridges to much more slender, but astutely designed, timber truss bridges. These colonially designed, but US-influenced, ‘lean and mean’ timber bridges were a far cry from the earlier, stockier, high-maintenance versions that were inherited from British/European designs. In some respects, such innovative local design was a symbolic way of releasing the restraining shackles of the colonial past and the growth of a nation. For over 40 years, these new style timber bridges, of various forms of successive improvement, dominated bridge construction in NSW to the extent that NSW was euphemistically known as the ‘timber bridge state’. It was not until innovations and improvements were made in steel production, steel fixing and concrete technology in the early 1930s that the newer materials started to replace timber.

New production technology for rail steel

New production technology for rail steel

Control Final Cooling Temperature on High Strength of the Pipeline Radio Yield Influence

In high strength pipeline steel rolling technology, the control of final cooling temperature of different microstructure, different microstructure of pipeline steel tensile strength, yield strength and the effects of different, thus determine its yield ratio differences. The results show that with lath bainite microstructure of the pipeline steel than with acicular ferrite microstructure of the pipeline steel with lower yield ratio, at the same time lath bainite microstructure in small dispersed precipitates in pipeline steel X80 pipeline steel to reduce the yield ratio is beneficial, for high strength pipeline steel production technology to provide the theory basis.