Arcelormittal

Connors Industrial, Inc

John A Rotole

Hyun Jo Jun

Dongwei Fan

Jean-Michel Mataigne

Jonas Staudte

Oscar Lanzi

Charles Krcmaric

William P Umlauf

Johnny C Brannbacka

Robert Bing

Oscar Lanzi Iii

A steel strip annealing furnace with a dew point control system. The furnace/control system can be more readily controlled to the desired dew point than the prior art control system and can handle the set point changes required as different types of steel coils are continuously run therethrough.

Steelmaking furnace with humidity control device

A method for producing a cold rolled and hot dip coated steel sheet is provided. The method includes casting a steel into a slab, reheating, hot rolling, cooling, coiling, descaling and cold rolling the slab. The cold rolled steel sheet is annealed so a layer of iron oxide forms on the surface with an internal oxidation underneath. The sheet is then heated so the surface is oxidized and the layer of iron oxide is fully reduced to obtain an internally oxidized depth between 200 nm and 100 &#x3bc;m which includes one or more of Si, Mn, Al, Ti containing oxides. The sheet is then hot dip coated and cooled.

Method for making a high strength multiphase steel

The invention deals with a cold rolled and hot dip steel sheet, with a tensile strength of at least 980 MPa, with yield strength above or equal to 500 MPa, with total elongation above or equal to 8%, the composition consisting by weight percent: 0.05&#x3c;C&#x3c;0.15%, 2&#x3c;Mn&#x2264;3%, Al&#x3c;0.1%, 0.3&#x3c;Si&#x3c;1.5%, 0.01%&#x3c;Nb&#x3c;0.05%, N&#x3c;0.02%, 0.1&#x3c;Cr+Mo&#x3c;1%, 0.0001&#x3c;B&#x3c;0.0025, Ti&#x3c;0.5%, V&#x3c;0.01%, S&#x3c;0.01%, P&#x3c;0.05% the remainder of the composition being iron and unavoidable impurities resulting from the smelting and the microstructure contains, in surface fraction: between 50 and 95% of martensite and between 5 and 50% of the sum of ferrite and bainite, wherein the ferrite grain size is below 10&#x3bc;&#x3b9;&#x3c4;&#x3b9;, and wherein the aspect ratio of the ferrite grain size is between 1 and 3. The steel according to the invention is oxidized and subsequently reduced during heating, soaking and cooling steps of the annealing.

High strength multiphase steel, production method and use

A method of annealing of steel sheets is provided which includes a first step consisting in fully oxidizing the surface of such steel sheet thus creating a fully oxided surface layer, a second step consisting in selectively oxidizing elements other than iron of such steel, in an area extending under said fully oxided layer, thus creating a selectively oxided internal layer and a third step consisting in fully reducing said fully oxided surface layer.

Method of annealing steel sheets

An apparatus and method for imaging the interior of a hot dip melt pot snout of a hot dip steel coating apparatus through the snout thereof. The system provided for high visual contrast and high resolution imaging, without the need for external illumination. The inventive apparatus and method image the interior of the hot dip melt pot snout at infrared wavelengths, and preferably in a wavelength range of 0.7 to 3 microns. The inventive apparatus and method provide valuable information about the condition of the hot dip melt pot snout and steel coating process which may be used to improve the quality of the produced coated steel.

Growing community of inventors

East Chicago, IN, United States of America

John A Rotole