Aluminum sheet materials, and production methods and alloy compositions therefor with reduced energy consumption and co2 emissions

Abstract

A method of manufacturing aluminum sheet material includes melting secondary aluminum and adding primary aluminum and other alloying elements to the melt to achieve an alloy composition of from 2.5 wt % to 6.3 wt % Mg, from 0.6 wt % to 2.5 wt % Si, from 0.2 wt % to 0.4 wt % Fe, from 0.05 wt % to 0.2 wt % Cr, up to 0.6 wt % Mn, up to 0.1 wt % Cu, up to 0.1 wt % Zn, the balance being Al and unavoidable impurities, wherein the Si and Mg contents satisfy the relationship (Si wt. %>0.5*Mg wt. %-0.65 wt. %). The alloy is then continuously cast into an aluminum sheet. Aluminum sheet material made according to the process, and an aluminum alloy adapted for the process are also disclosed.

What is claimed is: 
     
         1 . A method of manufacturing aluminum sheet material comprising the steps of:
 melting secondary aluminum;   adding primary aluminum and other alloying elements to the melt to achieve a composition consisting essentially of from 2.5 wt % to 6.3 wt % Mg, from 0.6 wt % to 2.5 wt % Si, from 0.2 wt % to 0.4 wt % Fe, from 0.05 wt % to 0.2 wt % Cr, up to 0.6 wt % Mn, up to 0.2 wt % Cu, up to 0.2 wt % Zn, the balance being Al and unavoidable impurities, wherein the Si and Mg contents satisfy the relationship (Si wt %>0.5*Mg wt %-0.65 wt %); and   continuously casting the aluminum into aluminum sheet.   
     
     
         2 . The method of manufacturing aluminum sheet material according to  claim 1  wherein the composition is from 2.5 wt % to 4.5% Mg and from 0.6 wt % to 1.6% Si. 
     
     
         3 . The method of manufacturing aluminum sheet according to  claim 2  wherein there is from 0.20 wt % to 0.30 wt % Fe, 0.05 wt % to 0.15 wt % Cr, up to 0.4 wt % Mn, up to 0.1 wt % Cu, and up to 0.1 wt % Zn. 
     
     
         4 . The method of manufacturing aluminum sheet material according to  claim 1  wherein the continuous casting is performed using a twin roll continuous caster. 
     
     
         5 . The method of manufacturing aluminum sheet material according to  claim 1  wherein the continuous casting is performed using a twin belt continuous caster. 
     
     
         6 . The method of manufacturing aluminum sheet material according to  claim 1  further comprising hot rolling the cast sheet, annealing the hot rolled sheet, cold rolling the annealed sheet, and annealing the cold rolled sheet. 
     
     
         7 . The method of manufacturing aluminum sheet material according to  claim 1  further comprising homogenizing the cast sheet, cold rolling the homogenized sheet, and annealing the cold rolled sheet. 
     
     
         8 . An aluminum sheet material that has been continuously cast from an alloy consisting essentially of from 2.5 wt % to 6.3 wt % Mg, from 0.6 wt % to 2.5 wt % Si, from 0.2 wt % to 0.4 wt % Fe, from 0.05 wt % to 0.2 wt % Cr, up to 0.6 wt % Mn, up to 0.2 wt % Cu, up to 0.2 wt % Zn, the balance being Al and unavoidable impurities, wherein the Si and Mg contents satisfy the relationship (Si wt %>0.5*Mg wt %-0.65 wt %). 
     
     
         9 . The aluminum sheet material according to  claim 8  wherein the composition of the alloy is from 2.5 wt % to 4.5% Mg and from 0.6 wt % to 1.6% Si. 
     
     
         10 . The aluminum sheet material according to  claim 9  wherein the composition of the alloy is from 0.20 wt % to 0.30 wt % Fe, 0.05 wt % to 0.15 wt % Cr, up to 0.4 wt % Mn, up to 0.1 wt % Cu, and up to 0.1 wt % Zn. 
     
     
         11 . The aluminum sheet material according to  claim 8  wherein the alloy was continuously cast using a twin roll continuous caster. 
     
     
         12 . The aluminum sheet material according to  claim 8  wherein the alloy was continuous cast using a twin belt continuous caster. 
     
     
         13 . An aluminum alloy adapted for continuous casting, the aluminum alloy comprising from 2.5 wt % to 6.3 wt % Mg, from 0.6 wt % to 2.5 wt % Si, from 0.2 wt % to 0.4 wt % Fe, from 0.05 wt % to 0.2 wt % Cr, up to 0.6 wt % Mn, up to 0.2 wt % Cu, up to 0.2 wt % Zn, the balance being Al and unavoidable impurities, wherein the Si and Mg contents satisfy the relationship (Si wt %>0.5*Mg wt %-0.65 wt %). 
     
     
         14 . The aluminum alloy according to  claim 13  wherein the composition of the aluminum alloy is from 2.5 wt % to 4.5% Mg and from 0.6 wt % to 1.6% Si. 
     
     
         15 . The aluminum alloy according to  claim 14  wherein the composition of the aluminum alloy is from 0.20 wt % to 0.30 wt % Fe, 0.05 wt % to 0.15 wt % Cr, up to 0.4 wt % Mn, up to 0.1 wt % Cu, and up to 0.1 wt % Zn. 
     
     
         16 . The aluminum alloy according to  claim 13  wherein the Si and Mg contents satisfy the relationship (Si wt %>0.5*Mg wt %-0.35 wt %). 
     
     
         17 . The aluminum alloy according to  claim 13  wherein the aluminum alloy has a solidification range of less than 100° C. 
     
     
         18 . The aluminum alloy according to  claim 17  wherein the aluminum alloy has a solidification range of less than 85° C. 
     
     
         19 . The aluminum alloy according to  claim 13  consisting essentially of from 2.5 wt % to 4.5 wt % Mg, from 0.6 wt % to 1.6 wt % Si, from 0.2 wt % to 0.3 wt % Fe, from 0.05 wt % to 0.15 wt % Cr, up to 0.4 wt % Mn, up to 0.1 wt % Cu, up to 0.1 wt % Zn, the balance being Al and unavoidable impurities, wherein the Si and Mg contents satisfy the relationship (Si wt. %>0.5*Mg wt. %-0.35 wt. %).