Plate made of a rolled aluminum alloy and a method for producing said plate

Abstract

A plate made of a rolled aluminum alloy and a method for producing said plate are disclosed. In order to achieve high strength values, it is proposed for the plate to have a partially recrystallized structure with a degree of recrystallization of less than 25%, wherein the non-recrystallized structure region of the structure is in the recovered state and has an average subgrain size of less than 10 μm in the rolling direction.

1 . A plate made of a rolled aluminum alloy with comprising the following alloy components:
 from 0.7 to 1.5 wt % silicon (Si),   from 0.5 to 1.3 wt % magnesium (Mg)   from 0.05 to 0.6 wt % manganese (Mn),   from 0.1 to 0.3 wt % zirconium (Zr),   
       and optionally
 up to 0.5 wt % copper (Cu), 
 up to 0.7 wt % iron (Fe), 
 up to 0.1 wt % chromium (Cr), 
 up to 0.2 wt % titanium (Ti), 
 up to 0.5 wt % Zink (Zn), 
 up to 0.2 wt % tin (Sn), 
 up to 0.1 wt % strontium (Sr), 
 up to 0.2 wt % vanadium (V), 
 up to 0.2 wt % molybdenum (Mo) 
 a balance aluminum, and 
 inevitable production-related impurities, with at most 0.05 wt % of each and at most 0.15 wt % collectively, 
 wherein the plate has a partially recrystallized structure with a degree of recrystallization of less than 25%, and a non-recrystallized structure region of the structure is in a recovered state and has an average subgrain size of less than 10 μm in a rolling direction. 
 
     
     
         2 . The plate according to  claim 1 , wherein the degree of recrystallization is less than 15%. 
     
     
         3 . The plate according to  claim 1 , wherein the average subgrain size in the rolling direction is less than or equal to 5 μm. 
     
     
         4 . The plate according to  claim 1 , wherein the plate is in a T6 state. 
     
     
         5 . The plate according to  claim 4 , wherein the plate has a yield strength (R p0.2 ) of greater than 350 MPa. 
     
     
         6 . The plate according to  claim 1 , wherein the rolled aluminum alloy contains comprises:
 from 0.9 to 1.3 wt % silicon (Si) and/or   from 0.75 to 0.95 wt % magnesium (Mg) and/or   from 0.3 to 0.5 wt % manganese (Mn) and/or   from 0.15 to 0.25 wt % zirconium (Zr)   and/or   from 0.1 to 0.5 wt % copper (Cu) and/or   up to 0.5 wt % iron (Fe).   
     
     
         7 . The plate according to  claim 1 , wherein an intermetallic phase of the aluminum alloy has Zr-containing particles with an average particle size of at most 100 nm, and a quantity of Zr-containing particles is greater than or equal to 1×10 6  particles/mm 2 . 
     
     
         8 . The plate according to  claim 7 , wherein the average particle size of the Zr-containing particles is in a range from 30 nm to 100 nm. 
     
     
         9 . A method for using the plate according to  claim 1 , comprising using the plate for machine construction. 
     
     
         10 . A method for producing a plate according to  claim 1 , comprising the following steps in the indicated sequence:
 casting a rolling ingot with the aluminum alloy,   multistep homogenization of the rolling ingot with subsequent accelerated cooling to room temperature, wherein the multistep homogenization comprises at least:
 a first homogenization at a first temperature in a range from 300° C. to 400° C. and 
 after the first homogenization, a second homogenization at a second temperature in a range from 500° C. to 10° C. below a solidus temperature of the aluminum alloy, 
   hot rolling the homogenized rolling ingot into the plate and subsequent heat treatment, comprising:
 solution annealing of the plate with subsequent accelerated cooling to room temperature, 
 natural aging of the solution annealed plate, optionally with a cold deformation with a degree of deformation in a range between 0.5 and 10%, and 
 subsequent artificial aging of the plate. 
   
     
     
         11 . The method according to  claim 10 , wherein:
 the first homogenization takes place with a first holding time of greater than or equal to 0.5 hours and/or up to 4 days and/or with a maximum heating rate of 5 K/min and/or   the second homogenization takes place with a second holding time of greater than or equal to 0.5 hours and/or up to 24 hours.   
     
     
         12 . The method according to  claim 10 , wherein the hot rolling of the homogenized rolling ingot takes place at a temperature that is 5° C. to 100° C. below the solidus temperature of the aluminum alloy. 
     
     
         13 . The method according to  claim 10 , wherein the solution annealing of the plate takes place at a temperature in a range from 460° C. to 580° C. and/or the solution annealing of the plate takes place with a holding time of 1 minute to 10 hours. 
     
     
         14 . The method according to  claim 10 , wherein the natural aging takes place at room temperature and/or with a holding time of up to 8 weeks. 
     
     
         15 . The method according to  claim 10 , wherein the artificial aging takes place at a temperature in a range from 130° C. to 210° C. and/or over a holding time of 1 to 24 hours. 
     
     
         16 . The method according to  claim 10 , wherein the heat treatment transforms the plate into a T6 state. 
     
     
         17 . The plate according to  claim 7 , wherein the quantity of Zr-containing particles is less than or equal to 100×10 6  particles/mm 2  and/or greater than or equal to 5×10 6  particles/mm 2 .