5xxx aluminium sheets with high formabilty

Abstract

The invention relates to a monolithic aluminium sheet made of a 5 xxx series aluminium sheet comprising in wt. % Mg:1.7-2.1, Mn:0.1-0.5, Fe:0.10 to 0.22, Si:0.05-0.25, Cu 0.01-0.20, Cr up to 0.1, Zn up to 0.15, Zr up to 0.1, Ti up to 0.05 wt %, rest aluminium and unavoidable impurities up to 0.05 each and 0.15 total. A method for producing the monolithic 5 xxx series aluminium sheet according to the invention comprises the steps of casting, pre-heating, rough hot rolling on a reversible mill with a rough hot rolling entry temperature of more than 440° C., finish hot rolling the ingot with a hot rolling exit temperature of at least 280° C., cold rolling. The invention is useful for automobile manufacturing.

1 . A monolithic 5xxx series aluminium sheet made of an alloy comprising in wt. %
 Mg: 1.7-2.1,   Mn: 0.1-0.5,   Fe: 0.10 to 0.22,   Si: 0.05-0.25,   Cu 0.01-0.20,   Cr up to 0.1,   Zn up to 0.15,   Zr up to 0.1,   Ti up to 0.05 wt %,   rest aluminium and unavoidable impurities up to 0.05 each and 0.15 total.   
     
     
         2 . A 5xxx series aluminium sheet according to  claim 1  wherein the Fe content is from 0.12 wt. % to 0.20 wt. %. 
     
     
         3 . A 5xxx series aluminium sheet according to  claim 1  wherein the Cr content is from 0.01 wt. % to 0.03 wt. 
     
     
         4 . A 5xxx series aluminium sheet according to  claim 1  wherein the Ti content is from 0.005 wt. % to 0.04 wt. 
     
     
         5 . A 5xxx series aluminium sheet according to  claim 1  wherein the Mn content is maximum 0.45%. 
     
     
         6 . A 5xxx series aluminium sheet according to  claim 1  wherein the sheet is in a O temper which is fully recrystallized. 
     
     
         7 . A 5xxx series aluminium sheet according to  claim 6  wherein the sheet has a Lankford coefficient of at least 0.605, optionally at least 0.610. 
     
     
         8 . A 5xxx series aluminium sheet according to  claim 6  having a volume fraction of cube texture of at least 13%, optionally of at least 14% and optionally of at least 15%. 
     
     
         9 . A 5xxx series aluminium sheet according to  claim 6  having a volume fraction of R texture of at most 11.0%, optionally of at most 10.0%. 
     
     
         10 . A 5xxx series aluminium sheet according to  claim 6  wherein the TYS in the LT direction, referred to as TYS(LT) o  is between 50 MPa and 100 MPa and optionally between 65 MPa and 95 MPa. 
     
     
         11 . A 5xxx series aluminium sheet according to  claim 6  wherein the maximum Fe content is 0.20 wt. % and the Lankford coefficient is at least 0.615.
 A method for producing a monolithic 5xxx series aluminium sheet according to  claim 1  comprising
 casting said ingot, 
 pre-heating the ingot optionally at a temperature between 440° C. and 520° C. 
 rough hot rolling on a reversible mill with a rough hot rolling entry temperature of more than 440° C., 
 finish hot rolling the ingot with a hot rolling exit temperature of at least 280° C., 
 cold rolling to obtain a cold rolled sheet. 
 
 
     
     
         13 . A method according to claim  12  wherein no annealing after hot rolling or during cold rolling is carried out. 
     
     
         14 . A method according to claim  12  wherein the cold rolled sheet further undergoes annealing in order to obtain a O temper which has a fully recrystallized microstructure optionally with a continuous annealing line operated in such a way that a temperature of at least 320° C., optionally at least 340° C. and at most 500° C. optionally at most 440° C. is reached by the sheet, optionally between 360° C. and 400° C. 
     
     
         15 . A product comprising a 5xxx series aluminium sheet according to  claim 1  for automobile manufacturing optionally as an automotive inner and/or reinforcement.