Process and plant for obtaining steel strip coils having cold-rolled characteristics and directly obtained in a hot-rolling line
AssigneesGiovanni Arvedi, Hoogovens Groep B.V.
InventorsGiovanni Arvedi, Giovanni Gosio
Life of this patent
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Abstract
A process for obtaining steel strip coils with characteristics of a cold-rolled product, directly in a hot-rolling line, comprises subsequently to steps of casting and thickness reduction at a temperature of more than 1100.degree. C. upon solidification, induction heating of the product and a further step of hot rolling, above point Ar.sub.3, a step of cooling and temperature control in a range of between 600.degree. and 250.degree. C., thus lower than said point Ar.sub.3, as well as one or more passes of cold-rolling in series, with final coiling of the obtained product. Also a preferred plant is described for putting into practice such a process.
Claims19
A process for obtaining steel strip coil directly from a hot-rolling line, said steel strip coil having characteristics of a cold-rolled product, comprising:
- mould casting a flat product having a thickness of less than 100 mm;
- reducing the thickness of said flat product immediately beyond the mould while maintaining a liquid core of said flat product;
- after solidification of the core of said flat product, further reducing the thickness of said flat product by rolling at a temperature greater than 1100.degree. C. to provide a flat product of 10-30 mm thickness;
- induction re-heating said flat product to provide a substantially homogeneous temperature throughout said flat product of about 1100.degree. C.;
- subjecting said flat product to a further stage of hot-rolling in the austenitic region at a temperature above a temperature value corresponding to transformation point Ar.sub.3 ;
- reducing the temperature of the flat product to a temperature lower than a temperature corresponding to said transformation point Ar.sub.3 ;
- and
- subjecting said flat product to at least one cold-rolling to obtain said steel strip having characteristics of cold-rolled product.
A plant for obtaining steel strip coils having characteristics of cold-rolled product, directly obtained in a hot-rolling line, comprising:
- means (10) for continuous casting of flat product (1) with a subsequent arc-shaped guide roller path (11);
- first reduction means (13, 15) for reducing thickness of the flat product in said arc-shaped path when it is in a condition of liquid core or immediately thereafter upon solidification of said flat product (1);
- heating means (21) for induction heating and homogenization of temperature throughout of the flat product (1) downstream of said first reduction means;
- at least one additional rolling stand (27) downstream from said heating means;
- cooling means (29) for cooling and controlling the temperature of the flat product (1) until under transformation point Ar.sub.3 immediately downstream of said additional hot-rolling stand (27);
- at least one cold-rolling stand (31) downstream of said cooling means;
- and
- coiler means (33) for winding the strip in a coil (1') downstream of said cold-rolling stand.
Dependencies are inferred from the claim text.