Tuesday, January 26, 2010
Kobe Steel Limited has announced that the world's first commercial plant using the ITmk3® Process successfully began production of iron nuggets in the United States on January 12th 2010. The next generation ITmk3 Process was developed by Kobe Steel.
Kobe Steel and Steel Dynamics Inc constructed the plant at Hoyt Lakes in Minnesota. Production of iron nuggets, which are used in steelmaking, will gradually increase in accordance with operating conditions and is anticipated to reach the facility's annual design capacity of 50,000 tonnes in mid 2010.
ITmk3 is an innovative next generation iron making process totally different in concept from the traditional blast furnace method. Since the discovery of the phenomenon in 1994, the process has undergone many stages of development resulting in the start of production of a commercial plant.
* The ITmk3 Process is noted for the following characteristics:
1. High grade iron nuggets can be produced in an extremely short time of about 10 minutes
2. The ITmk3 Process can use lower cost iron ore fines and steaming coal, which are difficult to use in blast furnace iron making
3. In comparison to pig iron produced in a blast furnace, the production of iron nuggets using the ITmk3 Process emits about 20% less carbon dioxide due to its good energy efficiency
With the start up of the commercial ITmk3 plant, Kobe Steel is moving quickly to popularize the ITmk3 Process in world markets. As a pioneer of this technology, Kobe Steel is working on iron nugget projects in North America, Vietnam, India, Russia, Australia and other countries, a cumulative production capacity of several million tonnes of iron nuggets.
Over the medium to long term future, steel demand is anticipated to continue increasing. Accordingly, electric arc furnace steelmakers are faced with a growing need for cold iron units, namely clean iron units such as blast-furnace pig iron and direct reduced iron. Kobe Steel believes the ITmk3 Process is one of the most effective ways to meet this new demand.
The ITmk3 Process, with its lower carbon-dioxide emissions and capital investment, is highly suitable for growing environmentally friendly steel industries in developing countries. Moreover the ITmk3 Process can use cheaper low grade iron ore and coal, which are difficult to use in blast furnace iron making, to keep raw material costs down for steel and mining companies. Along with these advantages, the real value of the ITmk3 Process is that it produces high-grade iron nuggets with better meltability than blast-furnace pig iron when used in the steelmaking stage.
For mining companies, the ITmk3 Process enables them to produce iron nuggets to add value to their natural resources. As a result, mining companies can expand their markets to include electric arc furnace steelmakers, in addition to their traditional customers, blast furnace steelmakers.
Grappling with environmental issues, the world steel industry faces a tight raw material market and higher costs due to the sharp increase in steel production. Under these conditions, the ITmk3 Process is an attractive alternative. Kobe Steel, with subsidiary Midrex Technologies Inc is the world's leader in direct reduction processes. Its MIDREX® Direct Reduction Process is used to produce nearly 60% of the world's direct reduced iron. As a member of the world steel industry, Kobe Steel has now commercialized ITmk3, a revolutionary iron making process that, in step with the present age, contributes to society.
* The ITmk3 Process
1. Pulverized iron ore and pulverized coal are agglomerated into ball-shaped pellets
2. The pellets are fed into a rotary hearth furnace. Reduction, melting and slag separation occur in about 10 minutes
3. The resulting product is high-grade iron nuggets
*Advantages of the ITmk3 Process
1. In comparison to pig iron produced in a blast furnace, the production of iron nuggets using the ITmk3 Process emits about 20% less carbon dioxide due to its good energy efficiency
2. Raw material pretreatment facilities (coke ovens, sintering plants and pellet plants) are unnecessary
3. ITmk3 is highly suitable for mining sites and can be profitable for even small mines
4. Operation is easy and production adjustments are also easy.
* Features of the Iron Nuggets
1. Iron nuggets are slag-free, high-purity iron units of the same quality as pig iron. They have a metallic iron content of 96% to 97%
2. Iron nuggets improve the productivity and energy efficiency of electric arc furnaces. With better meltability than blast furnace pig iron, iron nuggets can be continuously fed into EAFs
3. Iron nuggets are easy to transport and handle. High in density, they do not re oxidize or generate fines.
(Sourced from Kobe Steel)
Friday, March 28, 2008
Coated Steel – Galvanized steel:
Steel sheet coated through a heat process or through electrolysis with a layer of substance to protect the base metal (substrate) against corrosion. The most commonly used material is zinc which can be applied either using the heat process (hot-dip galvanizing) or using electrolysis (electro-galvanizing).
A. Galvanized steel products - Zinc coated galvanized GP and GC steel products are sturdy, light weight, bright and corrosion resistant. The functions of the zinc layer are mainly three folds:
(a) To retain the steel intact with its full initial strength
(b) To provide the surface a more pleasing appearance
(c) To increase the life of any suitable organic finishing system applied over it
In fact, zinc coatings provide the most effective and economic way of protecting steel against corrosion. Zinc coated steel is very environment friendly. Zinc is an integral part of our environment and occurs naturally in rocks, soil, air and water. Zinc is also an essential element for all life, from humans and animals to plants and micro – organisms. All types of zinc coated steel products are recyclable. In the last few decades, both the recycling technology and its capacity has been developed considerably in response to increasing environmental awareness and the cost-effective alternative supplies of raw materials for the steel and zinc industries. Presently, about 80 percent of the zinc is available from zinc coated steel that is recycled in
B. Galvanizing process: There are two main processes used in the production galvanized product namely: (i) Hot – dipped galvanizing and (ii) Electrolytic Galvanizing
(i) Hot – dipped Galvanizing – It is one of the basic and efficient corrosion resistant technique for producing galvanized steel. During the galvanizing process, steel coils are previously cleaned and pickled and then dipped into a bath of molten zinc to form a series of zinc / iron alloys integrated with the steel surface. As steel is removed from the bath, a layer of relatively pure zinc is deposited on the top of alloy layers. On solid deification, the zinc assumes a crystalline metallic luster, often known as “spangling”. The spangles can be enhanced and reduced depending on the end use. The life of galvanized coating in steel structures permanently immersed in liquids depends on the corrosion properties of the liquid and the thickness of the galvanized coating in the structure. Hot-dipped galvanizing technology has been greatly improved over the years and by the introduction of the sendzimir process or one of its variants, HDG products are introducing on the market share of electrolytic galvanized products in the western world because it is more cost effective.
(ii) Electrolytic Galvanized Steel - In the electrolytic galvanizing process, zinc ions from the electrolytic is deposited on the strip surface (cathode) under the influence of electric current using either soluble or insoluble anodes. The electrolyte is usually zinc sulfate or zinc chloride or mixed. The electro–galvanized strips are post treated with passivation solutions such as phosphate or chromate. The plating process controls the coating thickness resulting in much thinner coatings as well as double-side coatings. The automobile industries in
Wednesday, March 26, 2008
Stainless Steel - Rust and stain-resistant steel:
The resistance of stainless steel to corrosion and staining, low maintenance, relative inexpensive and familiar luster make it an ideal base material for a host of commercial applications.Stainless steels are distinguished from carbon steel by their content of chromium and, in certain cases, nickel. Adding chromium to carbon steel makes it more rust and stain-resistant and adding nickel to chromium stainless steel enhances the mechanical properties of the steel.
Stainless steels are iron-base alloys containing Chromium. Stainless steels usually contain less than 30% Cr and more than 50% Fe. They attain their stainless characteristics because of the formation of an invisible and adherent chromium-rich oxide surface film. This oxide establishes on the surface and heals itself in the presence of oxygen. Some other alloying elements added to enhance specific characteristics include nickel, molybdenum, copper, titanium, aluminum, silicon, niobium, and nitrogen. Carbon is usually present in amounts ranging from less than 0.03% to over 1.0% in certain martensitic grades. Corrosion resistance and mechanical properties are commonly the principal factors in selecting a grade of stainless steel for a given application. The resistance of stainless steel to many corrosive factors, such as exposure to water, air, acid and alkalis, is provided by a transparent protective chromium oxide film that forms on its exterior.
Stainless steels are manufactured in different types of grade, but all types contain at least 10% chromium, along with other elements added to develop specific properties. Depending on the quantity of the various elements present in a stainless steel alloy, it has a metallurgical structure that is characteristic of one of three basic stainless steel groups – (a) Martenistic, (b) Ferritic and (c) Austenitic. There are over 150 grades of stainless steel, of which fifteen are most common. The alloy is milled into sheets, plates, bars, wire, and tubing to be used in cookware, cutlery, hardware, surgical instruments, major appliances, industrial equipment, a structural alloy in automotive and aerospace assembly and building material in skyscrapers and other large buildings.
There are a large number of stainless steels produced. Corrosion resistance, physical properties, and mechanical properties are generally among the properties considered when selecting stainless steel for an application. A more detailed list of selection criteria is listed below:
(i) Corrosion resistance;
(ii) Resistance to oxidation and sulfidation;
(iv) Cryogenic strength;
(v) Resistance to abrasion and erosion;
(vi) Resistance to galling and seizing;
(v) Surface finish;
(vi) Magnetic properties;
(vii) Retention of cutting edge;
(viii) Ambient strength;
(x) Elevated temperature strength;
(xi) Suitability for intended cleaning procedures;
(xii) Stability of properties in service;
(xiii) Thermal conductivity;
(xiv) Electrical resistivity;
(xv) Suitability for intended fabrication techniques
Sunday, March 23, 2008
Environment friendliness of modern steel:Steel is the world's most recycled material. Steel's unique magnetic properties make it an easy material to recover from the waste stream, i.e., it can be recycled. The properties of steel remain unchanged no matter how many times the steel is recycled. The electric arc furnace (EAF) method of steel production can use recycled steel exclusively.
Most steel is made via one of two basic routes: (1) Integrated (blast furnace and basic oxygen furnace); (2) Electric arc furnace (EAF).
The integrated route uses raw materials (that is, iron ore, limestone and coke) and scrap to create steel. On the other hand, the EAF method uses scrap as its principal input.
The EAF method is much easier and faster since it only requires scrap steel. Recycled steel is introduced into a furnace and re-melted along with some other additions to produce the end product.
Steel can be produced by other methods such as open hearth. However, the amount of steel produced by these methods decreases every year.
Of the steel produced recently, about 65.0% was produced via the integrated route, 32.0% via EAF and 3.0% via the open hearth and other methods.
Steel is not a single product. There are currently more than 3,500 different grades of steel with many different physical, chemical, and environmental properties. Approximately 75% of modern steels have been developed in the last 20 years. If the
Steel is very friendly to the environment. It is completely recyclable, possesses great durability, and, compared to other materials, requires relatively low amounts of energy to produce. Innovative lightweight steel construction (such as in automobile and rail vehicle construction) help to save energy and resources. The steel industry has made immense efforts to limit environmental pollution in the last decades. Energy consumption and carbon dioxide emissions have decreased by one-half of what they were in the 1960s. Dust emissions have been reduced by even more.
Friday, March 21, 2008
Finished steel product descriptions:
- Plate (Heavy Steel Plate)
- Pipe (Heavy Pipe)
- Hot-Rolled Coil (Hot Rolled Steel)
- Pickled Hot Rolled Coil (Pickled Hot Rolled Steel)
- Cold-rolled Coil (Cold Rolled Steel or Full hard Steel)
- Finished Cold Rolled Coil (Annealed and Tempered Cold Rolled Steel)
- Electro-galvanized Coil (Electro-galvanized Steel)
- Hot Dip Galvanized Coil (Hot Dip Galvanized Steel)
- Tin Plate Coil (Electrolytic Tin Plated Steel)
- Tin-free Coil (Electrolytic Chrome Coated Steel)
- Organic Coated Coil (Organic Coated Steel)
- Cold Formed Sections
- Section Rolling
- Rebar (Reinforcing Bar)
- Engineering Steel (Tool Steel)
1. Plate (Heavy Steel Plate) - A flat Steel sheet rolled on a Hot Rolling mill. It can be found on the market in sheets and is further processed into finished products by the manufacturer. Heavy plate is used in a large number of sectors including structural Steels, shipbuilding, pipes, pressure vessels, boilers, heavy metal structures, and offshore structures. Typical thickness is from 2 to 20 mm. The maximum width is 1,860 mm.
2. Pipe (Heavy Pipe) - A flat plate Steel coil that is bent and welded into a tube. It can be found on the market for final use. A heavy-wall pipe is technically used to transport fluids (for example, oil, gases, water, and chemicals).
3. Hot-Rolled Coil (Hot Rolled Steel) - A coil of Steel rolled on a hot-strip mill (hot-rolled coil). It can be found on the market in coil or in sheets and is further processed into finished products by the manufacturer. The various types of hot rolled Steel have applications in virtually all sectors of industry. For example, transport, construction, shipbuilding, gas containers, pressure vessels, energy pipelines. Hot rolled Steel sheet with an anti-slip surface and a diamond or teardrop pattern is typically used for stairs, industrial floors and tailboards for goods vehicles. Typical thickness is from 2 to 7 mm. Typical width is from 600 to 2,100 mm.
4. Pickled Hot Rolled Coil (Pickled Hot Rolled Steel) - Hot-rolled Steel from which the iron oxides present at the surface have been removed in a pickling process. Pickled Hot Rolled Coil can be found on the market in coil or in sheets and is further processed into finished products by the manufacturer. The various types of pickled hot rolled Steel have applications in virtually all sectors of industry. For example, transport, construction, shipbuilding, gas containers, pressure vessels, energy pipelines. Typical thickness is from 2 to 7 mm. Typical width is from 600 to 2,100 mm.
5. Cold-rolled Coil (Cold Rolled Steel or Full hard Steel) - Obtained by a further thickness reduction of a pickled hot rolled coil. This step is achieved at low temperature in a cold-reduction mill. Cold-rolled Coil can be found on the market in coil, but requires a further heating process before being manufactured into finished products. The various types of Cold-rolled Steel are used as primary material for finished cold rolled coils and coated coils.Typical thickness is from 0.15 to 3 mm. Typical width is from 600 to 2,100 mm.
6. Finished Cold Rolled Coil (Annealed and Tempered Cold Rolled Steel) - Obtained by heat treatment (annealing) and strain-hardening of a Cold Rolled Steel in a way to achieve final mechanical properties that make the Steel suitable for further uses (forming and bending). Finished Cold Rolled Steel includes a wide range of different Steels which can be classified into the following main groups: formable Steels, high strength formable Steels, weathering structural Steels, structural Steels, hardenable Steels. It can be found on the market in coil or in sheets and is further processed into finished products by the manufacturer.
Finished Cold-rolled Steel features excellent forming properties, electromagnetic properties, paintability, weldability, and is suitable for fabrication by forming, pressing and bending. Applications include domestic applications, automotive applications, lighting fixtures, electrical components (stators, rotors), various kinds of sections roofing applications, profiled sheets, and wall elements.Typical thickness is from 0.3 to 3 mm. Typical width is from 600 to 2,100 mm.
7. Electrogalvanized Coil (Electrogalvanized Steel) - Obtained by electro-plating Finished Cold Rolled Steel with a thin layer of zinc or zinc-nickel to provide corrosion resistance. Electro-galvanized Coil can be found on the market in coil or in sheets and is further processed into finished products by the manufacturer. Electro-galvanized Coil features excellent forming properties, paintability, weldability, and is suitable for fabrication by forming, pressing and bending. Applications include domestic applications, building applications (for example, wall elements, roofing applications, automotive applications (for example, body in white for vehicles underbody auto parts), lighting fixtures, drums and various kinds of sections applications, profiled sheets. Typical thickness is from 0.3 to 3 mm. Typical width is from 600 to 2,100 mm.
8. Hot Dip Galvanized Coil (Hot Dip Galvanized Steel) - Obtained by passing Cold Rolled Coil through a molten zinc bath, in order to coat the steel with a thin layer of zinc to provide corrosion resistance. Hot Dip Galvanized Coil can be found on the market in coil or in sheets and is further processed into finished products by the manufacturer.
Hot Dip Galvanized Coil features excellent forming properties, paintability, weldability, and is suitable for fabrication by forming, pressing and bending. Applications include domestic applications, building applications (for example, wall elements, roofing applications), automotive applications (for example, body in white for vehicle underbody auto parts), lighting fixtures, drums and various kinds of sections applications, profiled sheets. Typical thickness is from 0.3 to 3 mm. Typical width is from 600 to 2,100 mm.
9. Tin Plate Coil (Electrolytic Tin Plated Steel) - Obtained by electro-plating a thin Finished Cold Rolled Coil with a thin layer of tin. Tin Plate Coil can be found on the market in coil or in sheets and is further processed into finished products by the manufacturer. Electrolytic Tin Plated Steel is used primarily in food cans, and industrial packaging (for example, small drums). Typical thickness is from 0.13 to 0.49 mm. Typical width is from 600 to 1,100 mm.
10. Tin-free Coil (Electrolytic Chrome Coated Steel) - Obtained by electro plating a thin Finished Cold Rolled Coil with a thin layer of Chrome. Tin-free Coil can be found on the market in coil or in sheets and is further processed into finished products by the manufacturer. Tin-free Coil is used primarily in food cans, and industrial packaging (for example, small drums). Typical thickness is from 0.13 to 0.49 mm. Typical width is from 600 to 1,100 mm.
11. Organic Coated Coil (Organic Coated Steel) - Obtained by coating a steel substrate with organic layers such as paint or laminated film. The substrate is mainly Hot Dip Galvanized Coil but may also be Electro-galvanized Coil or Finished Cold Rolled coil or Tin Free Steel. Organic Coated Coil can be found on the market in coil or in sheets and is further processed into finished products by the manufacturer. Organic Coated Coil is used in all activity sectors such as construction (for example, roof, wall and ceiling claddings, lighting, radiators), general industry (for example, office furniture, heating, ventilating, air conditioning), domestic appliances (for example, refrigerators, washing machines, small kitchen appliances, computer casings, VCR and DVD casings), and packaging. Typical thickness is from 0.15 to 1.5 mm. Typical width is from 600 to 1,300 mm.
12. Cold Formed Sections - Cold Formed Sections are made by roll forming narrow Finished Cold Rolled Coil or Hot Dip Galvanized Coil into a final shape such as a box section. Typical applications include light steel framing, automotive, and roadside crash barriers.
13. Section Rolling - A Steel Section rolled on a Hot Rolling mill. Steel Section includes I-beams, H-beams, wide-flange beams, and sheet piling. It can be found on the market for direct use. This product is used in construction, multi-story buildings, industrial buildings, bridge trusses, vertical highway supports, and riverbank reinforcement.
14. Rebar (Reinforcing Bar) - A Steel Reinforcing Bar is rolled on a Hot Rolling mill. It can be found on the market for direct use or is further processed into finished products by the manufacturer. This product is used to strengthen concrete in highway and building construction also as primary product for the Wire Rod process.
15. Engineering Steel (Tool Steel) - Engineering Steel is rolled on a Hot Rolling mill. It can be found on the market and is further processed into finished products by the manufacturer. This steel is used in the manufacture of tools, dies, components for engines, drives, equipment, transmissions.
Wednesday, March 19, 2008
Iron ore, its beneficiation and agglomeration - as required for iron and steel industry:
B. Types of
C. Grades of
(i) Lumpy/Fine Ore:
(ii) Natural pellet: It is a term coined by producers in some Asian counties, to designate sized iron ore used directly in Sponge Iron production.
(iii) Blue Dust: Blue Dust is the name given to naturally occurring, extremely friable, high grade Haematite
D. Beneficiation of
Asian, specially of Indian origin of ore, is generally rich in iron (Fe) content but theAlumina content is very high which call for special adjustments/techniques for production of iron/steel at the cost of productivity and quality and hence money. Some of the mines have set up a Beneficiation plant to beneficiate Magnetite ore with approximately 35% Fe to high grade Iron Ore Concentrates.
E. Agglomeration of
(a) Sinter : Sinter is a clinker like aggregate which is normally produced from relatively coarser fine iron ore (normally –3mm) mixed with coke breeze (-3mm), limestone dolomite fines (-3mm) and other metallurgical return wastes from the plant. Sinter is a much preferred input/raw material in blast furnaces. It improves BF operation and productivity and reduces coke consumption in blast furnace. Presently, more than 70% hot metal in the world (in
(b) Pellet: Pellets are normally produced in the form of Globules from very fine iron ore (normally –100 mesh) and mostly used for production of Sponge Iron in gas based plants, though they are also used in blast furnaces in some countries in place of sized iron ore.
Sunday, March 16, 2008
Types of finished steel products and their terminologies:
Steel is not a single product. There are currently more than 3,500 different grades of steel with many different properties - physical, chemical, environmental, 75% of which have been developed in the last 20 years. If the Eiffel Tower were to be rebuilt today the engineers would only need one-third of the amount of steel, modern cars have new steels with higher strength reducing the overall shell weight by 25%. Some of the finished steel terminologies have been discussed below:
(1) Annealing: Annealing is a heat treatment process. With this, steel products are reheated to a suitable temperature to remove stresses, resulting from previous processing and to soften them and/or improve their machinability and cold forming properties.
(2) Billet: Billet is a semi-finished steel product with a square cross section up to 155mm x 155mm. This product is either rolled or continuously cast and is further processed by rolling to produce finished products like wire rods, merchant bars and other sections. The range of semi-finished products above 155 mm x 155 mm is called blooms.
(3) Carbon Steel: A type of steel generally having no specified minimum quantity of any alloying element and containing only an incidental amount of any element other than carbon, silicon, manganese, copper, sulfur and phosphorus.
(4) Coated Steel (Galvanized & Color coated): Steel sheet coated through a heat process or through electrolysis with a layer of substance to protect the base metal (substrate) against corrosion. The most commonly used material is zinc which can be applied either using the heat process (hot-dip galvanizing) or using electrolysis (electro-galvanizing). An organic coating (paint, plastic) can also be deposited on the layer of zinc. The zinc-coated steel is often referred to as "galvanized steel".
(5) Electric Sheets: These sheets are produced from steel alloyed with silicon (up to 3.5%) and are used in the manufacture of alternators, transformers and motors. Grain oriented electrical sheets have a high silicon content and are used for the manufacture of large transformers. Non-oriented products are used in electric motors and small transformers.
(6) Flat Steel Products: A flat steel product is a plate product or a (hot or cold) rolled strip product. Typically steel is rolled between sets of rollers to produce the final thickness. Plate products vary in dimensions from 10 mm to 200 mm and thin flat rolled products from 1 mm to 10 mm. Plate products are used for ship building, construction, large diameter welded pipes and boiler applications. Thin flat products find end use applications in automotive body panels, domestic 'white goods' products, 'tin cans' and whole host of other products from office furniture to heart pacemakers.
(7) Long Steel Products: A long product is a rod, a bar or a section - typical rod products are the reinforcing rods for concrete, engineering products, gears, tools etc. are typical of bar products and sections are the large rolled steel joists (RSJ) that are used in building construction projects. Wire-drawn products and seamless pipes are also part of the long products group.
(8) Refining Stand: A stage in the process of making crude steel, during which the crude steel is further refined (i.e., most residual impurities are removed) and additions of other metals may be made before it is cast.
(9) Semi-finished Products: Steel products such as billet, blooms and slabs. These products can be made by direct continuous casting of hot steel or by pouring the liquid steel into ingots, which are then hot rolled into semi-finished products.
(10) Slab: A semi-finished steel product obtained by rolling ingots on a rolling mill or processed through a continuous caster and cut into various lengths. The slab has a rectangular cross section and is used as a starting material in the production process of flat products, i.e., hot rolled coils.
(11) Strip: Flat steel coil products, with widths of less than 600mm for hot rolled products and less than 500mm for cold rolled products.
(12) Thin Strip Continuous Casting: Casting technology that takes liquid steel and casts it into solid strip in one step, thereby eliminating the need for a continuous slab caster and hot strip mill.