Thyssen Stahl Ag

Thyssenkrupp Stahl Ag

Thyssen Aktiengesellschaft Vorm. August Thyssen-hutte

Manfred Espenhahn

Rudolf Kawalla

Hans Pircher

Carl-Dieter Wuppermann

Fritz Bolling

Christof Holzapfel

Andreas Bottcher

Thomas Heller

Brigitte Hammer

Waldemar Wolpert

J&uuml;rgen Schneider

Klaus G&uuml;nther

J&uuml;rgen Esdohr

Klaus Peters

Andreas B&ouml;ttcher

Hans Huneus

Andres Bottcher

Manfred Folwaczny

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

The invention concerns hot-rolled steel strip no more than 5 mm thick, optionally less than 2 mm thick, made of high-tensile steel, that contains 0.08%-0.25% carbon, 1.20% to 2.0% manganese, and 0.02% to 0.05% aluminum, and optionally up to 1.0% chromium, up to 0.1% copper, up to 0.5% molybdenum, up to 0.1% nickel, up to 0.009% nitrogen, up to 0.0025% B, and optionally a stoichiometric amount of titanium in relation to nitrogen. The steel strip has a greater than 95% martensitic structure, and a tensile strength of 800 to 1400 N/mm,.

Hot-rolled steel strip and method of making it

The invention relates to a process for producing strips of homogenous structures and characteristics made of non-alloyed and low-alloyed steel by continuous hot rolling in several roll passes in the austenitic region and subsequently in the ferritic region, as well as coiling. The invention is characterised in that continuous-cast strip and/or strip rough rolled in the austenitic region, starting with a temperature T&gE;Ar,&plus;30&deg; C., with a total degree of deformation of e,&gE;30% is rolled in two or several roll passes in the austenitic region and in that the rolling stock is intensively cooled after every roll pass until the ferritic transformation has been completed, after which the rolling stock is end rolled to final thickness in the ferritic range in several passes with a total degree of deformation e,&gE;60%.

Hot-rolling steel strip

Process for producing a grain-orientated electrical steel sheet

A process for the production of grain oriented magnetic steel sheets having improved remagnetization losses consisting essentially of (in % by weight) more than 0.005% to 0.10% C, 2.5 to 6.5% Si, 0.03 to 0.15% Mn, 0.010 to 0.050% S, 0.010 to 0.035% Al, 0.0045 to 0.0120% N, and 0.020 to 0.300% Cu, and up to 0.15% Sn, the balance being iron and inevitable impurities. The process includes continuous casting or strip casting slabs with the above composition.

Process for the production of grain oriented magnetic steel sheets

A process for the production of grain oriented magnetic steel sheets comprises through-heating slabs containing more than 0.005% C, 2.5 to 6.5% Si, 0.03 to 0.15% Mn, 0.010 to 0.050% S, 0.010 to 0.035% Al, 0.0045 to 0.0120% N, and 0.020 to 0.300% Cu, the balance being iron and residual impurities, to a temperature which is lower than the solubility temperature T.sub.1 of magnesium sulfide and higher than the solubility temperature T.sub.2 of copper sulfide, T.sub.1 and T.sub.2 being dependent on the silicon content. The through-heated slabs are then hot roughed, followed by hot finish rolling at an initial temperature of at least 960.degree. C. and a final rolling temperature of 880.degree. C. to 1,000.degree. C., to produce a hot rolled strip having a thickness in the range of 1.5 to 7 mm. During this last step, at least 60% of the total nitrogen content precipitates in the form of coarse AlN particles. Thereafter, the hot rolled strips are annealed at temperature of 880.degree. C. to 1,150.degree. C., followed by cooling at a cooling rate higher than 15 .degree. K./sec to induce further precipitation of AlN and copper sulfide particles. Thereafter the strip is cold rolled in one or more cold rolling stages to a final strip thickness of 0.1 mm to 0.5 mm, subjected to recrystallization and decarburization annealing in a wet atmosphere containing H.sub.2 and N.sub.2. A separating agent containing mainly MgO is then applied to both surfaces of the strip. The strip is then high temperature annealed, an insulating coating is applied and the strip is subjected to a final annealing.

An apparatus is disclosed for the electroplating of metal strips, and more particularly for the zinc-coating of steel strip, which comprises a tank filled with electrolyte liquid and immersed therein, at least one anode which is disposed above a strip to be electrolytically coated and at least one anode disposed below said strip, both of said anodes being parallel to said strip. The anode disposed above the strip is electrolytically consumable and made of an electrolytically depositable metal for deposition on said strip and the anode disposed below the strip consists essentially of a material that is insoluble in the electrolyte and not electrolytically consumable. Each anode is connected to a source of current, the anode disposed below said strip being provided with means for disconnecting it from said source of current.

Electroplating apparatus

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Essen, Germany

Manfred Espenhahn