ALUMINUM SHEET AND ALUMINUM ALLOY SHEET FOR PRESS WORK AND PAINTING

摘要

PURPOSE:To improve the critical drawing ratio at deep drawing and the brightness of Al sheets for painting by rolling by rolling rolls whose surface is roughened by specifying a max. roughness and the number of holes deeper than a specified depth in a specific measuring length. CONSTITUTION:Rolling is performed by rolling roll whose surface has a max. roughness (R max) of 3-20 mu in a 25.4 mm measuring length L and >=25 holes W having a depth H of >=2.0 mu in the 25.4 mm measuring length L. Further, amplitudes S of wavinesses L'' having a wave length of 250-2500 mu on the surface of an Al and Al alloy sheets are restricted to be <=1 mu. Thus, the surface of Al and Al alloy sheets is roughened and the limit drawing ratio at deep drawing work and the brightness after painting are improved.