Thyssenkrupp Stahl Ag

Thyssenkrupp Steel Ag

Fried Krupp Ag Hoesch-krupp

Hoesch Stahl Aktiengesellschaft

Thyssenkrupp Steel Europe Ag

Bernhard Engl

Thomas Heller

Klaus-Dieter Horn

Klaus Horn

Rudolf Kawalla

Hans Pircher

Harald Hofmann

Eberhard Sowka

Günter Stich

Axel Fuchs

Wolfgang Rasim

Franz-Josef Biniasz

Werner Zimmermann

Thomas Gerber

Rudlof Kawalla

Pino Tesè

Klaus Dieter Schmidt

Manfred Menne

Margit Huser

The invention provides a method which allows reliable production of steel products from a light steel. The steel products according to the invention exhibit isotropic deformation behavior and are ductile at low temperature with high yield strengths. This is achieved according to the invention by a method for producing a steel product, in particular a steel sheet or steel strip, wherein a steel strip or sheet is produced from steel which contains (in % by weight): C: &#x2266;1.00%, Mn: 7.00 to 30.00%, Al: 1.00 to 10.00%, Si: &#x3e;2.50 to 8.00 %, Al+Si: &#x3e;3.50 to 12.00%, B: &#x3c;0.01%, Ni: &#x3c;8.00%, Cu: &#x3c;3.00%, N: &#x3c;0.60%, Nb: &#x3c;0.30%, Ti: &#x3c;0.30%, V: &#x3c;0.30%, P: &#x3c;0.01% and iron and unavoidable impurities as the remainder, from which strip or sheet the finished steel product is subsequently produced by cold forming that takes place at a degree of cold forming of 2 to 25%.

Method for producing a steel product

The invention relates to a method for producing hot strip which features good forming ability and increased strength. This is achieved in that a hot strip (W) which is produced in particular from continuous casting in the shape of reheated slabs or slabs obtained directly from the casting heat, from thin slabs or cast strip, based on a steel comprising (in mass %) C: 0.001-1.05%; Si: &#x2266;1.5%; Mn: 0.05-3.5%; Al: &#x2266;2.5%, if necessary further elements such as Cu, Ni, Mo, N, Ti, Nb, V, Zn, B, P, Cr, Ca and/or S, with the remainder being iron as well as the usual accompanying elements, is continuously finish rolled and subsequently continuously cooled, with cooling taking place in at least two subsequent cooling phases (t, t) of accelerated cooling, to a final temperature; with the first cooling phase (t) of accelerated cooling starting at the latest three seconds after the last pass of finish rolling; and with the hot strip (W) during the first cooling phase (t) of accelerated cooling being cooled at a cooling rate of at least 150&#xb0; C./s.

Method for producing a hot-rolled strip

The invention relates to a method for producing a hot strip, in particular for producing a hot strip intended for the production of a cold strip with good deep-drawing characteristics; in which a steel melt comprising (in % by weight) C:&lE;0.07%, Si:&lE;0.5%, Mn:&lE;2.5%, Al:&lE;0.1%, N:&lE;0.01%, P:&lE;0.025, B:&lE;0.05, if need be up to a total of 0.35% of Nb, Ti and V, with the remainder being iron and the usual impurities is melted; in which the steel melt is continually output in one strand (S) from a permanent casting mould ( ); in which the cast strand (S) immediately after discharge from the permanent casting mould ( ) is led along a cooling line ( ); in which the strand (S) is intensively cooled down to a temperature of A &plusmn;25 K at a cooling rate (a ) of at least 3 K/s; in which, following its intensive cooling, the strand (S) is cooled by exposure to air for at least 30 seconds; and in which the strand (S) itself or thin slabs (D) divided off the strand (S) is/are reheated in a soaking furnace ( ) before the strand (S) or the thin slabs (D) are hot rolled to form hot strip. The method according to the invention makes it possible, during processing of low-alloyed low-carbon steels, to reduce the required temperature in the soaking furnace such that the stress on the furnace is reduced without there being any reduction in the quality of the hot strip produced, or of the cold strip made from said hot strip.

Method for producing a hot strip

The invention relates to a higher-strength steel strip or steel sheet comprising a predominantly ferritic-martensitic microstructure with a martensite content of between 4 and 20%, wherein the steel strip or steel sheet, apart from Fe and impurities due to smelting, comprises (in % by weight) 0.05-0.2% C, &lE;1.0% Si, 0.8-2.0% Mn, &lE;0.1% P, &lE;0.015% S, 0.02-0.4% Al, &lE;0.005% N, 0.25-1.0% Cr, 0.002-0.01% B. Preferably the martensite content is approximately 5% to 20% of the predominantly martensitic-ferritic microstructure. Such a higher-strength steel strip or steel sheet made from a dual phase steel comprises good mechanical/technological properties even after being subjected to an annealing process which includes an overageing treatment. Furthermore, the invention relates to a method for producing steel strip or steel sheet according to the invention.

High resistance steel band or sheet and method for the production thereof

The present invention concerns a method for the production of cold-rolled bands or sheets from low-alloy steel with a maximum of 0.2% C, Al, Ti, V, Nb respectively and a maximum of 1% Si and Mn respectively, in addition to a portion of boron required for N binding (>0,78&times;N), the remainder being constituted by iron and unavoidable impurities, wherein said steel is cast after melting to slabs, thin slabs or a band, which are hot-rolled at a starting temperature above 1100&deg; C. and at a final temperature below Ar and wherein the hot band is then drawn and cold-rolled at a temperature below 650&deg; C., whereupon the cold band is annealed independently of the degree of cold-rolling at a low temperature that could possibly vary depending on the composition of the steel and ranging from 520 to 780&deg; C. during a period of time that is sufficiently long to allow for complete recrystallization. The method disclosed makes it possible to simplify manufacturing and to lower production costs associated with the manufacture of a completely recrystallized cold-rolled band or sheet.

Method for producing cold-rolled bands or sheets

In order to provide a cost-effective, time saving method for producing aging-resistant strip consisting of aluminum-killed steel, for which, initially, a strip is produced in the usual manner by rolling and the rolled strip is annealed continuously, the still hot strip is wound into a coil and cooled to room temperature, the strip, cooled in the coil, being finally finished.

Method for producing aging-resistant strip from an aluminum-killed steel

A method of producing cold-rolled, high-strength steel strip with good plasticity and isotropic properties out of steel comprising no more than 0.08% carbon, no more than 10% silicon, no more than 1.8% manganese, between 0.010 and 0.10% phosphorus, no more than 0.02% sulfur, no more than 0.08% aluminum and no more than 0.008% nitrogen by weight plus one or more of the elements titanium, vanadium, niobium, and zirconium, the remainder being iron, by hot rolling, cold rolling, and recrystallization annealing; followed by temper rolling. The steel contains either three times as much titanium or six times as much niobium or zirconium as nitrogen.

Method of producing cold-rolled, high-strength steel strip with good

The invention concerns a method for manufacturing a worked weldable, low temperature ferritic steel consisting of

Worked low-temperature tough ferritic steel

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Dortmund, Germany

Bernhard Engl