Plant and method for the production of metal

Abstract

Plant for the production of metal products comprising: a main rolling line configured to roll thin slabs; a main casting line of thin slabs associated downstream to a heating and/or maintenance furnace to heat and/or maintain the cast thin slabs at a uniform temperature, the main casting line being positioned upstream of and aligned with said main rolling line, the main rolling line being configured to roll the thin slabs arriving at least from the heating and/or maintenance furnace; an auxiliary rolling line provided with at least one rolling unit configured to roll conventional slabs and obtain thin slabs, and with a transfer unit positioned downstream of the rolling unit and configured to transfer the thin slabs rolled by the latter to the heating and/or maintenance furnace.

1 . Plant for the production of metal products comprising:
 a main rolling line ( 12 ) configured to roll thin slabs;   a main casting line ( 11 ) of thin slabs associated downstream to a heating and/or maintenance furnace ( 18 ) to heat and/or maintain the cast thin slabs at a uniform temperature, said main casting line ( 11 ) being positioned upstream of and aligned with said main rolling line ( 12 ), said main rolling line ( 12 ) being configured to roll the thin slabs arriving at least from said heating and/or maintenance furnace ( 18 );   an auxiliary rolling line ( 22 ) provided with at least one rolling unit ( 24 ) configured to roll conventional slabs and obtain thin slabs, and with a transfer unit ( 25 ) positioned downstream of said rolling unit ( 24 ) and configured to transfer the thin slabs rolled by the latter to said heating and/or maintenance furnace ( 18 ),   
       characterized in that said plant comprises: a first induction heating unit ( 27 ) interposed between said heating and/or maintenance furnace ( 18 ) and said main rolling line ( 12 ) and configured to heat the thin slabs arriving from said heating and/or maintenance furnace ( 18 ) with a rapid heating system, before they are sent for rolling in said main rolling line ( 12 ). 
     
     
         2 . Plant as in  claim 1 , characterized in that said first induction heating unit ( 27 ) is configured to apply a first heating condition on the thin slabs arriving from said main casting line ( 11 ), and a second heating condition, different from the first, on the thin slabs arriving from said auxiliary rolling line ( 22 ). 
     
     
         3 . Plant as in  claim 2 , characterized in that said first heating condition provides a uniform heating action on the entire length of the thin slabs. 
     
     
         4 . Plant as in  claim 2  or  3 , characterized in that said second heating condition provides a differentiated heating action between the head and tail end of the thin slabs. 
     
     
         5 . Plant as in any claim hereinbefore, characterized in that said auxiliary rolling line ( 22 ) comprises a second induction heating unit ( 31 ) interposed between said rolling unit ( 24 ) and said transfer unit ( 25 ) and configured to heat the thin slabs rolled by said rolling unit ( 24 ). 
     
     
         6 . Plant as in  claim 5 , characterized in that said second induction heating unit ( 31 ) is configured to apply on the thin slab a differentiated heating action along its longitudinal extension in order to homogenize the temperature thereof. 
     
     
         7 . Plant as in any claim hereinbefore, characterized in that said transfer unit ( 25 ) is configured to deliver the rolled slabs in an intermediate zone of said heating and/or maintenance furnace ( 18 ). 
     
     
         8 . Plant as in any claim hereinbefore, characterized in that it comprises a secondary casting line ( 132 ) positioned parallel to said main casting line ( 11 ), and in that said secondary casting line ( 132 ) comprises its own heating and/or maintenance furnace ( 118 ) provided with at least one transfer module ( 134 ) configured to transfer the thin slabs from the latter to said heating and/or maintenance furnace ( 18 ) of said main casting line ( 11 ). 
     
     
         9 . Plant as in any claim hereinbefore, characterized in that said auxiliary rolling line ( 22 ) is disposed substantially parallel to the main casting line ( 11 ). 
     
     
         10 . Method for the production of metal products that provides:
 to roll thin slabs by means of at least one main rolling line ( 12 );   to cast thin slabs in a main casting line ( 11 ) and subsequently to heat them and/or maintain them at a uniform temperature in a heating and/or maintenance furnace ( 18 );   to perform said rolling of the thin slabs contained in said heating and/or maintenance furnace ( 18 ) by means of said main rolling line ( 12 ) positioned downstream of and aligned with said main casting line ( 11 );   to roll conventional slabs in an auxiliary rolling line ( 22 ) by means of a rolling unit ( 24 ) in order to obtain thin slabs to be transferred, by means of a transfer unit ( 25 ), to said heating and/or maintenance furnace ( 18 );   
       characterized in that it comprises at least a first induction heating, with a rapid heating system, of said thin slabs, by means of a first induction heating unit ( 27 ), carried out downstream of the heating and/or maintenance carried out in said heating and/or maintenance furnace ( 18 ) and before they are introduced into said main rolling line ( 12 ). 
     
     
         11 . Method as in  claim 10 , characterized in that said first induction heating comprises the application of a first heating condition on the thin slabs arriving from said main casting line ( 11 ), and a second heating condition, different from the first, on the thin slabs arriving from said auxiliary rolling line ( 22 ). 
     
     
         12 . Method as in  claim 10  or  11 , characterized in that said first heating condition provides a uniform heating action on the entire length of the thin slabs. 
     
     
         13 . Method as in  claim 11  or  12 , characterized in that said second heating condition provides a differentiated heating action between the head and tail end of the thin slabs. 
     
     
         14 . Method as in any claim from  10  to  13 , characterized in that said first induction heating provides to raise the temperature of the thin slab by a value comprised between 30° C. and 80° C. 
     
     
         15 . Method as in any claim from  10  to  14 , characterized in that it provides a second heating, by means of a second induction heating unit ( 31 ), of said thin slabs exiting from said at least one rolling unit ( 24 ), before they are introduced into said transfer unit ( 25 ). 
     
     
         16 . Method as in  claim 15 , characterized in that said second heating provides to apply a differentiated heating along the longitudinal extension of said thin slabs in order to homogenize the temperature thereof.