Patent ID: 7647804

Claim:
A working method comprising providing a work piece having an initial width ( 2 A 0 ); and rolling the work piece in at least two consecutive passes, wherein: a first pass comprises passing the work piece through an oblong-shaped caliber having a minor axis and a major axis, a ratio of a length ( 2 A 01 ) of the minor axis to the initial width ( 2 A 0 ) of the work piece being (A 01 /A 0 )≦0.75 so as to provide the work piece with a cross-section having a minor axis and a major axis; and a second pass comprises passing the work piece through a square-shaped caliber having a diagonal dimension ( 2 A S1 ), a ratio of the diagonal dimension ( 2 A S1 ) to a length ( 2 B 1 ) of the major axis of the cross-section of the work piece being (A S1 /B 1 )≦0.75 so as to introduce a large strain in the work piece.