Aluminum alloy plate for producing molded article which is to be subjected to bake coating

Abstract

An aluminum alloy plate to be subjected to a bake coating contains silicon (Si) and magnesium (Mg) with the balance being aluminum (Al) and inevitable impurities. In order to set the content of Mg 2 Si in a range of 0.50% by weight≦Mg 2 Si≦1.00% by weight, when the Si content by weight percent is taken on an x-axis of rectangular coordinates and the Mg content by weight percent is taken on a y-axis of the rectangular coordinates, the Si and Mg contents are set in a region in a diagram formed by sequentially connecting a point A (0.18, 0.31), a point B (1.3, 0.31), a point C (1.3, 0.64), a point D (0.37, 0.64), a point E (0.37, 1.0), a point F (0.18, 1.0) and the point A (0.18, 0.31). Thus, a bake-hard effect can be obtained, and the aluminum alloy plate can be produced at a relatively low manufacturing cost.

What is claimed is:  
     
         1 . An aluminum alloy plate which is used for producing a molded article to be subjected to a bake coating, comprising silicon (Si), magnesium (Mg), aluminum (Al) and inevitable impurities, 
 wherein when the Si content by weight percent is taken on an x-axis of rectangular coordinates and the Mg content by weight percent is taken on a y-axis of the rectangular coordinates, the Si and Mg contents are set in a region in a diagram formed by sequentially connecting a point A (0.18, 0.31), a point B (1.3, 0.31), a point C (1.3, 0.64), a point D (0.37, 0.64), a point E (0.37, 1.0), a point F (0.18, 1.0) and the point A (0.18, 0.31).    
     
     
         2 . An aluminum alloy plate which is used for producing a molded article to be subjected to a bake coating, comprising silicon (Si) and magnesium (Mg) as requisite chemical constituents and further contains at least one of Fe, Ti, B and Cr as an optional chemical constituent, with the balance being aluminum (Al) containing inevitable impurities, 
 wherein when the Si content by weight percent is taken on an x-axis of rectangular coordinates and the Mg content by weight percent is taken on a y-axis of the rectangular coordinates, the Si and Mg contents are set in a region in a diagram formed by sequentially connecting a point A (0.18, 0.31), a point B (1.3, 0.31), a point C (1.3, 0.64), a point D (0.37, 0.64), a point E (0.37, 1.0), a point F (0.18, 1.0) and the point A (0.18, 0.31); and the Fe content is set in a range of 0.2% by weight≦Fe≦0.6% by weight; the Ti content is set in a range of 0.01% by weight≦Ti≦0.2% by weight; the B content is set in a range of 0.0005% by weight≦B≦0.05% by weight; and the Cr content is set in a range of 0.03% by weight≦Cr≦0.2% by weight.    
     
     
         3 . An aluminum alloy plate which is used for producing a molded article to be subjected to a bake coating, comprising silicon (Si), magnesium (Mg) and copper (Cu) as requisite chemical constituents and further contains at least one of Fe, Ti, B and Cr as an optional chemical constituent, with the balance being aluminum (Al) containing inevitable impurities, 
 wherein when the Si content by weight percent is taken on an x-axis of rectangular coordinates and the Mg content by weight percent is taken on a y-axis of the rectangular coordinates, the Si and Mg contents are set in a region in a diagram formed by sequentially connecting a point A (0.18, 0.31), a point B (1.3, 0.31), a point C (1.3, 0.64), a point D (0.37, 0.64), a point E (0.37, 1.0), a point F (0.18, 1.0) and the point A (0.18, 0.31); and the Cu content is set at Cu≦0.2% by weight; the Fe content is set in a range of 0.2% by weight≦Fe≦0.6% by weight; the Ti content is set in a range of 0.01% by weight≦Ti≦0.2% by weight; the B content is set in a range of 0.0005% by weight≦B≦0.05% by weight; and the Cr content is set in a range of 0.03% by weight≦Cr≦0.2% by weight.    
     
     
         4 . A method of making the aluminum alloy plate of  claim 1 , comprising: 
 preparing a molten metal having the composition of  claim 1  to produce a plate material then subjecting the plate material to cold rolling to provide a cold rolled plate;    then thermally treating the cold rolled plate by sequentially subjecting the cold rolled plate to a solution treatment and a stabilizing thermal treatment; and then optionally subjecting the plate to a straitening treatment.    
     
     
         5 . A method of making the aluminum alloy plate of  claim 2 , comprising: 
 preparing a molten metal having the composition of  claim 1  to produce a plate material then subjecting the plate material to cold rolling to provide a cold rolled plate;    then thermally treating the cold rolled plate by sequentially subjecting the cold rolled plate to a solution treatment and a stabilizing thermal treatment; and then optionally subjecting the plate to a straitening treatment.    
     
     
         6 . A method of making the aluminum alloy plate of  claim 3 , comprising: 
 preparing a molten metal having the composition of  claim 1  to produce a plate material then subjecting the plate material to cold rolling to provide a cold rolled plate;    then thermally treating the cold rolled plate by sequentially subjecting the cold rolled plate to a solution treatment and a stabilizing thermal treatment; and then optionally subjecting the plate to a straitening treatment.