Thyssenkrupp Stahl Ag

Thyssenkrupp Steel Ag

Thyssenkrupp Electrical Steel Ebg Gmbh

Carl-Dieter Wuppermann

Rudolf Kawalla

Karl Ernst Friedrich

Brigitte Hammer

J&uuml;rgen Schneider

Hans Pircher

Olaf Fischer

Manfred Espenhahn

Karl Telger

Klaus G&uuml;nther

Klaus Peters

Jürgen Schneider

Thomas B&ouml;hm

Joergen Schneider

Hans Huneus

Wolfgang Rasim

Andreas B&ouml;ttcher

The present invention relates to a hot-rolled steel strip for further processing to form non-grain oriented electrical sheet with the following composition (in % by weight) C: &#x3c;0.02%, Mn: &#x2266;1.2%, Si: 0.1-4.4%, Al 0.1-4.4%, wherein the sum formed from the Si content and twice the Al content is &#x3c;5%, P: &#x3c;0.15%, Sn: &#x2266;0.20%, Sb: &#x2266;0.20%, the remainder iron and unavoidable impurities, with a strip thickness which is at most 1.8 mm, and with a partially softened structure which is characterised by a high intensity for the &#x3b1; fibre (fibre representation of orientation distribution functions) in the region of 0&#xb0; to 60&#xb0;, wherein the ratio I/Iformed from the intensity Iof the position (112) &#x3c;110&#x3e; to the intensity Iof the position (001) &#x3c;110&#x3e; is &#x3e;0.4 and the ratio I/Iformed from the intensity Iof the position (111) &#x3c;110&#x3e; to the intensity Iof the position (001) &#x3c;110&#x3e; is &#x3e;0.2.

Hot-rolled strip intended for the production of non-grain oriented electrical sheet and a method for the production thereof

The invention relates to non-grain oriented magnetic steel sheets which can be produced as final annealed and as a non-final annealed types in such a way that they have improved magnetic polarisation and reduced magnetic reversal losses compared with the previously achieved values. This is achieved in that a suitably composed steel, during its cooling starting from a maximum initial temperature of 1,300&#xb0; C., passes through a temperature range with substantially complete exclusion of a purely austenitic structure (&#x3b3; phase), in which range it comprises an austenite/ferrite dual phase multi-structure (&#x3b1;, &#x3b3; multi-phases), so the magnetic steel sheet, after hot rolling, etching, cold rolling and annealing of the hot strip obtained after hot rolling, has a magnetic polarisation J&#x2267;1.74 T, measured in the longitudinal direction of the strip or sheet and at a magnetic field strength of 2,500 A/m and a value P(50) of the magnetic losses of &#x3c;4.5 W/kg, measured in the longitudinal direction of the strip at J=1.5 T and a frequency f=50 Hz.

Non-grain oriented magnetic steel strip or magnetic steel sheet and method for its production

The present invention relates to a method for producing non grain-oriented magnetic steel sheets in which hot strip is produced from an input stock such as cast slabs, strip, roughed strip, or thin slabs, made of steel comprising (in weight %) C: 0.001-0.05%; Si: &lE;1.5%; Al: &lE;0.4% with Si&plus;2Al&lE;1.7%; Mn: 0.1-1.2%; if necessary up to a total of 1.5% of alloying additions such as P, Sn, Sb, Zr, V, Ti, N, Ni, Co, Nb and/or B; with the remainder being iron as well as the usual accompanying elements; in that the input stock is hot-rolled directly from the casting heat or after preceding reheating to a reheating temperature between min. 1000&deg; C. and max. 1180&deg; C. in several deformation passes, and subsequently coiled, wherein during hot-rolling at least the first deformation pass takes place in the austenitic region and at least one further deformation pass takes place in the two-phase mixing region austenite/ferrite, and wherein during rolling in the two-phase mixing region a total deformation &egr; of at least 35% is achieved.

Method for producing non-grain oriented electric sheet steel

The invention relates to a method for producing non-grain-oriented hot-rolled magnetic steel sheet in which from a raw material such as cast slabs, strip, roughed strip or thin slabs produced from a steel comprising (in weight %) C: 0.0001-0.05%; Si: &lE;1.5%; Al: &lE;0.5%, wherein &lsqb;% Si&rsqb;&plus;2&lsqb;% Al&rsqb;&lE;1.8; Mn: 0.1-1.2%; if necessary up to a total of 1.5% of alloying additions such as P, Sn, Sb, Zr, V, Ti, N, Ni, Co, Nb and/or B, with the remainder being iron and the usual impurities, in a finishing roll line at temperatures above the Ar temperature, a hot strip with a thickness &lE;1.5 mm is rolled, wherein at least the last forming pass of hot rolling is carried out in the mixed region austenite/ferrite and wherein the total deformation &egr; achieved during rolling in the mixed region austenite/ferrite is <35%. With the method according to the invention, it is possible in particular to economically produce thicker magnetic steel sheet which is not grain-oriented and which has good magnetic properties.

Method for producing non-grain-oriented magnetic steel sheet

Method of producing non-grain-oriented electrical sheet

A process for the production of grain-oriented electric quality sheet by melting a silicon steel and casting the melt continuously into a strand having a thickness of 25-100 mm. During solidification the strand is cooled to a temperature above 700&deg; C. and divided into thin slabs. The thin slabs then pass through an equalization furnace standing in line where they are reheated to a temperature &lE;1170&deg; C. and continuously rolled in a multi-stand hot rolling mill to give hot strip having a thickness of &lE;3.0 mm. The first shaping pass is performed at a temperature in the rolling stock up to 1150&deg; C. The reduction in thickness is at least 20%. The hot strip is cold rolled in one or more stages with recrystallizing intermediate annealing to a final thickness in the range of 0.15-0.50 mm. The cold strip is then annealed with recrystallization and decarburization, furnished with a predominantly MgO-containing annealing separator and given a final annealing for imprinting a Goss texture. The strip is then coated with an electric insulation and given a stress-free annealing.

Process for the production of grain-oriented electric quality sheet with low remagnetization loss and high polarization

The invention relates to a method to produce non-grain-oriented magnetic steel sheet made of thin-slab or slab casting with low specific total loss and high polarisation and favourable mechanical properties. It is a characteristic of the invention that the steel slabs are hot rolled either directly from the casting heat or after a reheating to T&gE;900 &deg; C. and two or more metal forming passes are performed in the two-phase region austenite/ferrite in the course of finishing rolling.

Method for producing non-grain oriented magnetic sheet steel

Growing community of inventors

Krefeld, Germany

Carl-Dieter Wuppermann