1. History and Fundamentals of Iron- and Steelmaking
Iron has been utilized by man since approximately 4,000 B.C. Through the last 6,000 years, the art of ironmaking has gradually turned into the science of steelmaking and continuous casting. The progress in technology over those years will be presented to create a foundation for the remaining MSTS 201: Steelmaking presentations. Included will be the histories of ironmaking, steelmaking and continuous casting, as well as how the steel industry spurred the industrialization of the modern world. The process route varieties will be explained, as well as the “steelmaking disease.” The session concludes with an overview of world steel statistics, a steel market review and a statistical overview of the host country’s current steel industry situation.
2. Sustainability in Steelmaking
Safety and environmental considerations have taken prominent positions in sustainable steel production. Among these basic needs, eight sustainability indicators have been developed, summarizing the responsibility of steel industry employers to their employees, their social roles and their environmental behaviors. Indicators will be presented to illustrate what it means for a steel company to be sustainable. These indicators focus on greenhouse gas emissions, energy and material efficiencies, environmental management systems, reduction in lost-time injuries, employee training, investment in new processes and technology, and providing a defined value to society.
3. Raw Materials
Steel production requires efficient sourcing and use of raw materials. Iron ore, coal, alloys, fuels, fluxes and recycled products will be described in terms of origin, availability, trade, chemical and physical properties, and logistics involved in bringing them to steel-producing sites. Preparation and efficient use for cost-effective production will be discussed. The session concludes with an introduction of modern recycling technologies to reutilize all kinds of dust, sludge and other iron-bearing mill waste according to the material efficiency indicators of the sustainability approach.
4. Burden Preparation
Most of the raw materials introduced previously cannot be utilized directly in the iron and steelmaking processes applied. Burden physical and thermal preparation is required. Carbon-based fuel must be either ground to powder to be injected or baked to coke to be top-charged into the blast furnace. The processes and their worldwide application are discussed in detail. The direct use of iron ore is limited in metallurgical processes due to performance restrictions. Thermal preparation processes like sintering and pelletizing are introduced, as well as cold preparation technologies, namely briquetting and stone making. Other alternatives are discussed, as well as the importance of material quality testing and material behavior simulation in the melting process. The session concludes with a brief discussion about lime and dololime production.
5. Blast Furnace Process
Blast furnaces have been used for more than 100 years to produce iron suitable for steel production. Many factors contribute to efficient, sustainable iron production. The overall blast furnace (BF) design and process will be outlined. The metallurgy of iron ore reduction and melting will be presented and discussed in detail. Hot metal quality and ways to influence it will be discussed, as well as slag formation and processing to valuable byproducts. BF top gas composition and dust types and utilization are introduced. An overview of material and heat balances for the blast furnace will be discussed in detail. Maintenance considerations, production costs, blast furnace design and facilities, plant utilities, recent advancements in instrumentation, modeling, automation and environmental aspects will also be addressed. The session will conclude with the challenges faced by blast furnace ironmaking.
6. Alternative Ironmaking
Not every region in the world has been able to develop coking coal-based ironmaking technology to industrial application. In some regions, non-coking coal or other primary energy sources are available. To develop a steel industry in these countries, direct reduced iron technologies came into industrial application. Many new processes have been introduced, and others are being investigated to produce iron from raw materials that are not suitable for blast furnace production. Current, viable technologies such as Midrex, Corex and Finex, will be presented, including the metallurgy and final product characteristics and process byproducts. The session concludes with the introduction of smelting reduction technology and the processes under development for industrial application.
7. Hot Metal Pretreatment
On its way from the blast furnace to the steel meltshop, liquid hot metal must be transported, stored intermediately and processed. The common technologies and metallurgies for hot metal pretreatment, like desulfurization, dephosphorization and desiliconization, are also presented, detailing the methods used and the benefits of the processes to the final steel product. The role of hot metal solidified for scrap replacement in direct steel meltshops is explained. Environmental aspects are discussed.
8. BOF Steelmaking
The basic oxygen furnace (BOF) steelmaking process (also called the LD process) began in the 1950s in Europe. Since that time, the BOF process is the primary process to produce large quantities of high-purity steel from blast furnace iron. The history and current state of the process will be presented. The oxidation metallurgy of the BOF — including raw material considerations, material and heat balances, oxygen blowing and tap procedures — will also be detailed. The course will include information on BOF maintenance, production costs and plant utilities, and will give an overview of the current technology available for instrumentation, modeling and automation. A description of environmental systems for BOF steelmaking will be included, as will the challenges facing steel produced via a BOF.
9. EAF Steelmaking
Electric arc furnace (EAF) technology, which converts raw materials to steel product, has been available for more than 100 years. In the last 20 years, the process has spread rapidly across the globe as a viable alternative to the BOF for producing many steel products. Similar to the BOF section of the course, this section will detail the metallurgy of the EAF, including raw material considerations, material and heat balances, oxygen blowing and tap procedures, and the many variations in EAF designs. This section will also highlight maintenance requirements, plant utilities required and an overview of the current technology available for instrumentation, modeling and automation. An overview of the environmental systems and the future challenges for EAF steelmaking will conclude the section.
10. Alternative Steelmaking
This section is comprised of a brief overview showcasing recent, viable alternative steelmaking technologies: direct scrap melting with oxygen and coal (KMS) technology, energy optimized furnace (EOF) technology, induction furnace (IF) technology and submerged arc furnace (SAF) technology. Finally, the micro-mill technology will be introduced. Two general routes are available: an EAF/Consteel-based steelmaking route and a cupola furnace-based, hot-metal-to-steel processing route.
11. Steel Refining
The chemical and temperature refinement of liquid steel is critical to the final cast product. The fundamentals of the metallurgical operations used to deoxidize and refine steel will be presented, including the various treatment stations for reheating, degassing and alloying liquid steel. The different stations are necessary to produce the broad range of chemistries required for today’s steel market. Interstitial-free steel grades are processed differently than sour gas service grades; likewise, a different process route is used to produce high-alloy steels for tools and roller bearings. The linking of these treatment stations to the overall process route will be presented, as well as the variety of process routes that can occur between the steel melting furnace and the final solidification process.
12. Casting Fundamentals & Casting Process
The casting section will begin with a history and overview of ingot casting and the current benefits of continuous casting steel via the ingot process. The history and evolution of continuous casting will then be described, focusing on the different cross-sectional shapes which can be cast and the markets served by each type. The outline of the process starts with the general description of the machine elements. The operations include the introduction of the physical and metallurgical models to understand the process, followed by the explanation of the importance of re-oxidation prevention, flow control and slag carryover control. The benefits of technologies like electromagnetic stirrers are described, and mold powder technology is introduced. This part concludes with the technology developments of the last four decades. The metallurgical phenomena discussion includes all kind of possible surface and inner defects on continuously cast products, their origin and countermeasures to minimize or avoid them. Cleanliness of steel is discussed, as well as solidification effects and minimizing of negative quality effects caused by segregation. Various mold technologies, strand mechanics, the bending/unbending process, cooling processes and casting tensions are included. As in the previous sessions, the material and heat balance of the process is introduced, and maintenance issues, productivity aspects, production costs, plant utilities and the latest technological developments in modeling and instrumentation will be discussed. The session concludes with casting/rolling applications like thin slab and direct strip casting.
13. Steel Markets and Applications
Steel is one of the most widely used materials in the world. Steel grades can be classified into one of four categories: construction steel, ultralow-carbon steel, line pipe steel and engineering steel. Each category will be described in terms of its requirements in steel chemistry and applications. Innovations will be introduced and discussed.
14. Production Planning
Production planning requires an understanding of raw material availability, current operating conditions, current orders, customer requirements and equipment availability, among many other considerations. Continuous production processes are merged with batch processes to produce an efficient production sequence. An overview of how an order becomes a product will be given for different production systems.