Glossary
Don’t know what a slab is? No problem. Here you’ll find explanations of specialist terms and abbreviations from the Steel world.
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
A
AOD converter
Special converter for corrosion, acid and heat-resistant steels, in which the carbon content is reduced by injecting argon and oxygen. AOD: Abbreviation for argon oxygen decarburization.
B
Blast furnace
Plant smelting processed iron ore into hot metal. Its functioning is based on the countercurrent principle. Or in other words: The batch (consisting of ore, burden, additives and coke) is charged from the top – usually via a rotating chute. Wind, preheated in the blast-furnace-gas-heated hot-blast stoves and injected via the bottom tuyeres arranged in a ring over the furnace cross section, is flowing in counter direction. Coke serves as a reducing agent. Depending on the charge and the type of operation it is possible to produce various hot metals or even ferroalloys. A furnace remains in operation for many years (furnace campaign). Capacity and cost-efficiency of a blast furnace can be increased by larger furnace units, automatic charge, burden preparation, high hot-wind temperatures, oxygen-enriched wind or counterpressure at the charging door. By-products of the blast furnace are blast furnace gas and blast furnace slag.
Blast furnace gas
A quarter of the blast furnace gas consists of carbon monoxide (CO) and is completely utilized in a modern steelworks.
Blast furnace sand
Blast furnace slag (granulated) quenched with water and vitreously solidified. Raw material for cement manufacturing.
C
Casting rolling line
Modern production line based on the thin slab technology manufacturing hot strips from molten crude steel in only one production stage.
Coil
Steel strip wound into a coil.
Continuous casting
Semi-continuous process manufacturing slabs from molten steel. In the process, the steel is cast via a distributor into a cooled mold, determining the dimensions (width, thickness) of the slab. From this mold, the casting strand with the skin just solidifying, and guided between rolls during the additional cooling, is diverted horizontally and cut with a flame-cutting torch to the required slab length.
Crude steel
May be available in liquid or even solid form. In both cases this is a crude product. In the liquid state, it is used for the casting of blooms, strands or steel.
Cut-to-length line
This is used to manufacture sheet steels from wide strip and cutting to length slit strips (slit strip in bars). Interconnected are straighteners and rolling stands. The cut-to-length line is usually positioned parallel to the slitting line.
D
Downstream activities
Subsequent processing steps of flat steel with high value added, such as surface finishing, steel service or joining technology.
E
Electric steel
Steel molten in the electric arc furnace or in the induction furnace. The mode of operation of the electric steel furnaces allows the production of chemically resistant steel grades such as tool and high-speed steels, specialty steels for mechanical engineering, aerospace and nuclear steels as well as magnetic materials.
F
Finishing shop
Setups and operations providing steel products with the desired appearance after forming (straightening, cutting, etc.).
Four-high reversing mill
Plant for manufacturing heavy plate with a four-high stand (four rolls).
H
Heat treatment (quenching and tempering)
Type of heat treatment with hardening (quenching at a high temperature) and tempering (batch annealing at a lower temperature).
Heat treatment of heavy plates
Annealing of the heavy plates in furnaces to set certain microstructures and thus properties, which cannot be achieved immediately within the rolling process.
Standard processes:
- Water or oil hardening and, if necessary, tempering
- Normalizing and, if necessary, tempering
Heavy plate
Hot-rolled sheets with a minimum thickness of 3 mm. Heavy plates are supplied in all alloyed and unalloyed steel grades.
Hot-dip coating
Here, the sheet or strip is coated by being dipped into a bath of molten metal (such as zinc, tin, aluminum, lead or their alloys). Dimensional standard DIN EN 10143.
Hot rolled sheet
Sheet cut from hot-rolled wide strip mainly in thicknesses of up to 15 (max. 20) mm.
Hot rolling
Forming process. The rolling at high temperature ensures a major thickness reduction so that e.g. the slab used can be formed into thin hot-rolled strip.
Hot strip mill
Mills for the manufacturing of hot-rolled strip. Fully continuous plants consisting of one or several roughing stands as well as a finishing mill with seven finishing stands.
Hot (wide) strip
Hot-rolled product with a rectangular cross-section and a width of at least 600 mm wound to coils immediately after rolling with edges placed on top of one another as accurately as possible (like a mainspring). Manufactured on hot (wide) strip mills, mainly continuously in thicknesses of 1.5 to 25.0 mm and widths of up to 2,000 mm. Hot (wide) strip is used as input stock for sheet steel and heavy plates as well as cold (wide) strip.
I
Interior high pressure remolding
Innovative forming process, in which a pressurized liquid is used as an active medium in a closed die. It allows the manufacturing of highly complex shapes such as tubular output sections.
K
L
M
Multi processing line
Plant, in which several process steps take place in one pass, which must be performed subsequently in different units during conventional manufacturing.
N
O
Oxygen-steel converter
Refractory-lined vessel for refining (converting) pig iron into steel. By top-blowing oxygen onto the molten material, the carbon content decreases to up to 0.1%.
P
Pig iron
according to DIN EN 10 001, is an alloy of iron and more than 2% carbon (C). In addition, it may contain other elements in a limited amount. (Mn < 30 %, Si < 8 %, P < 3 %, Cr < 10 %, others < 10 %). Hot metal is processed into steel or cast iron. Non-phosphorous pig iron can be divided into grades with a low and high phosphor content.
Primer
Primer between steel and a coating material, which adheres poorly or not at all when applied directly to steel. Primers are excellent protective coatings against corrosion and base coats for paint coats later on.
Pusher furnace
Furnace for the heating up of continuous casting segments (slabs) at rolling temperature. The slabs are pushed through the furnace. Other type of design: Walking beam type furnace – here, the slabs are transported through the furnace by lifting them via the walking beams and depositing them further up front.
PVD/CVD
Abbreviation for Physical or Chemical Vapor Deposition.
Surface finishing with metallic, organic or inorganic layers by separation from the heating phase.
Q
Quality steels
Term from DIN EN 10020 – “Definition and classification of grades of steel“. A difference is made between plain-carbon steels (base steels, unalloyed quality, unalloyed stainless steels) and alloyed steels (alloyed quality and alloyed stainless steels).
Quench facility
Device, in which during the quenching process with pressurized water the sheets to be hardened are fixed with hydraulically positioned "feet". (Other type of design: Roll quench installation; here, during quenching, the strip moves on between guide rollers.)
R
ReflectionsOne®
A wide range of colors for building with steel was developed by the color designer Friedrich Ernst v. Garnier. In the meantime, already numerous major buildings have been realized successfully with the new colorfulness.
Reversing stand
Reversing stand: Rolling stand forming the rolling stock by passing back and forth between the adjustable rolls. The plant consists of one or two rolling stands of which at least one is carrying our several passes in a reverse operation.
S
Scales
Oxide layer forming on the finish during batch annealing, rolling or forging of steel. A scale coat consists of several oxidation layers differing chemically (rolling skin).
Secondary metallurgy
or ladle metallurgy is the generic term for all processes regarding deoxidation, degassing, alloying, inclusion shape control and the degree of purity of steel. A large part of these takes place under vacuum.
Shaft furnace
Unit for melting pig iron from in-plant materials of the steelworks containing iron so far unusable.
Sheet
Flat product in thicknesses of 0.35 to less than 3.00 mm: cold-rolled flat products made from soft or higher-strength grades for cold forming. These are mainly coated metallically or organically.
Simultaneous and Concurrent Engineering
Close technical cooperation with the automotive industry with regard to the material and production integrated autobody development.
Sinter
In the sinter plant, ore dusts and concentrates are turned into larger pieces. For this purpose, the fine-grained, iron-oxide-containing material is heated to the point that it starts melting on the surface and then cakes.
Sintering plant
Here, the originally fine-grained iron ore with various admixtures, coke, additives, etc., is sintered. “Sintering" is a continuous process agglomerating ore dust on a sintering strand. This is necessary, since the fine-grained ore in its original state cannot be used in the blast furnace. This would affect the gas circulation of the blast furnace.
Slab
Compact bloom made from crude steel. In steelworks, this is the product of the casting process used as input stock of the rolling mill for the production of hot strips or four-high plates.
Slag
During every melting process, an oxidic mass develops, floating due to its low specific weight on the hot metal or molten steel. The unwanted accompanying elements separated from the iron oxide are transferred to the slag. In the solidified state, the structure of the slag is vitreous or stony. Slag from the steelworks is a material: Blast furnace slag is processed into slag cement (iron Portland and blast furnace), granulated-slag brick, foamed slag, slag lime, road-building materials, track ballast and slag wool. Finely ground phosphor-containing converter slag is a valuable fertilizer.
Slit strip
Wide hot or cold-rolled strip (rolling width > 600), split by slitting on the slitting line to final strip widths < 600mm. Delivered in coils, but also cut to length to strip in bars. The slitting is also used for coated wide strips.
Special structural steels
Materials, for which manufacturers based on their development work designate particular quality exceeding the profile of requirements of standards.
Stainless
English designation for stainless steel.
Steel service center
Steel service centers are modern, highly efficient processing facilities with a comprehensive delivery and service program of slit strips, sheets and blanks in hot and cold rolled design, coated and in stainless steel. They are understood as a link between roll manufacturers and steel processors.
Supply Chain Management
The supply chain management takes into account the entire supply chain of a company with the goal to optimize the flow of information and material between its internal and external suppliers, its manufacturing area, its distributors and its customers.
Surface finishing
Corrosion protection for high-grade flat steel by coating with metallic (zinc, nickel, aluminum) or organic coatings (color, plastic).
Sustainability
The weighting of the economic, social and ecological goals is of equal standing as their networked analysis.
T
Tandem mill
Plant, in which the rolling stands are arranged one behind the other (tandem arrangement). In general, tandem cold strip lines consist of two to five duo, quarto, or sexto stands positioned close together, which the rolling stock passes once or several times.
Tear(-type) plates
Hot-rolled sheets with tear pattern, used as checker and tear plates.
Tensile strength
Maximum of the stress-elongation curve determined within tensile testing. Calculated from the quotient of the maximum tensile force and the output cross-section. Unit of measure: MPa.
Thin strip casting
Here, with the technology applied at ThyssenKrupp, liquid steel is cast between two rotating rolls and then solidifies to a hot strip. Since conventional hot rolling is not required, this saves one complete process step.
Tinplate
Tin-coated, cold-rolled blackplate in rated thicknesses of 0.17 to 0.49 mm, double-reduced tinplate from 0.14 to 0.29 mm of soft, unalloyed steel according to DIN EN 10203. The tin is applied electrolytically on a single side or both sides in identical or different coating thickness (“differential tin coated"). Tin layer graded from 1.0 to 10 g/m² per side. An additional coat of paint may improve the corrosion resistance. For the most part, used in the packaging industry (with a high recycling rate!) also for household goods and toys. Technical delivery conditions in DIN 10205.
Torpedo ladles
Special track-bound transportation container for hot metal. They have a capacity of up to 300 tons of hot metal at a temperature of approx. 1.500 °C.
Toughness
The work stored by deformation or another type of energy conversion up to breakage.
U
ULSAB
Ultra-Light-Steel Auto Body. The ULSAB-AVC (Advanced Vehicle Concepts) program is an important element of the constant efforts of the international steel industry to ensure the future of the material steel as the first choice for automotive manufacturers.
V
Vacuum facility
Unit for the after-treatment of steel under significantly reduced pressure suitable to achieve especially good degrees of purity, low gas content and tight alloy tolerances. Thus, high quality requirements can be met.
W
Wear-resistant steels
Group of steels which based on their microstructure and/or hardness feature a high wear resistance when subjected to friction or impact. ThyssenKrupp trademark: XAR®.
Z