New 6xxx aluminum alloys

Abstract

New 6xxx aluminum alloy sheet products are disclosed. The new 6xxx aluminum alloy sheet products may contain, for instance, from 0.95 to 1.25 wt. % Si, from 0.65 to 0.95 wt. % Mg, wherein (wt. % Mg)/(wt. % Si) is not greater than 0.99:1, from 0.50 to 0.75 wt. % Cu, from 0.02 to 0.40 wt. % Mn, and from 0.03 to 0.26 wt. % Cr, wherein (wt. % Mn)+(wt. % Cr) is at least 0.22 wt. %. The new 6xxx aluminum alloy sheet products may have a thickness of from 0.5 to 4.0 mm and may realize an improved combination of properties, such as an improved combination of two or more of strength, ductility (elongation), castability, fracture behavior and corrosion resistance.

What is claimed is: 
     
         1 . An aluminum alloy sheet product comprising:
 from 0.95 to 1.25 wt. % Si;   from 0.65 to 0.95 wt. % Mg;
 wherein (wt. % Mg)/(wt. % Si) is not greater than 0.99:1 
   from 0.50 to 0.75 wt. % Cu;   from 0.02 to 0.40 wt. % Mn;   from 0.03 to 0.26 wt. % Cr;
 wherein (wt. % Mn)+(wt. % Cr) is at least 0.22 wt. %; 
   from 0.01 to 0.30 wt. % Fe;   up to 0.25 wt. % Zn;   up to 0.20 wt. % Zr;   up to 0.20 wt. % V;   up to 0.15 wt. % Ti;   the balance being aluminum, optional incidental elements and impurities;   
       wherein the aluminum alloy sheet product has a thickness of from 1.0 to 4.0 mm; 
       wherein the aluminum sheet product realizes a tensile yield strength (LT) of at least 315 MPa in the T6 temper, wherein the T6 temper comprises artificially aging at 225° C. (437° F.) for 30 minutes. 
     
     
         2 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy sheet product includes from 0.55 to 0.70 wt. % Cu. 
     
     
         3 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy sheet product includes from 0.15 to 0.35 wt. % Mn. 
     
     
         4 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy sheet product includes at least 0.08 wt. % Cr. 
     
     
         5 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy sheet product realizes a three-point bend extension of at least 10.0 mm in the T6 temper. 
     
     
         6 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy sheet product realizes a three-point bend extension of at least 16.0 mm in the T4 temper. 
     
     
         7 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy sheet product realizes a maximum depth of attack of not greater than 200 micrometers when tested in accordance with ASTM G110-92(2015) for 6 hours. 
     
     
         8 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy sheet product is filiform corrosion resistant, realizing at least comparable filiform corrosion resistance to AA6111 when tested in accordance with ASTM G85 A2. 
     
     
         9 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy sheet product is fully recrystallized. 
     
     
         10 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy sheet product realizes an area weighted average grain size of from 20 to 60 micrometers. 
     
     
         11 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy sheet product realizes from 10 to 25 vol. % cube texture. 
     
     
         12 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy sheet product realizes a dispersoid area fraction of from 0.5 to 1.1%. 
     
     
         13 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy sheet product realizes an f/r of from 0.05 to 0.11. 
     
     
         14 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy sheet product is an automotive sheet product.