Method for reducing the grain size in a massive, cylindrical workpiece, comprises rolling a pressure roller over a circumference of the cylindrical workpieces and then delivering in radial direction of the cylindrical workpieces

摘要

The method for reducing the grain size in a massive, cylindrical workpiece, comprises rolling a pressure roller (2) over a circumference of the cylindrical workpieces and then delivering in radial direction of the cylindrical workpieces in such a way that the rolled pressure roller enters in a contact zone (4) in a surface near area of the workpieces and stretches the workpieces. The grain size in an edge area (6) that stretches itself from surface (5) of the workpiece to 4% of output diameter of the cylindrical workpiece in the direction of the interior of the workpiece is reduced. The method for reducing the grain size in a massive, cylindrical workpiece, comprises rolling a pressure roller (2) over a circumference of the cylindrical workpieces and then delivering in radial direction of the cylindrical workpieces in such a way that the rolled pressure roller enters in a contact zone (4) in a surface near area of the workpieces and stretches the workpieces. The grain size in an edge area (6) that stretches itself from surface (5) of the workpiece to 4% of output diameter of the cylindrical workpiece in the direction of the interior of the workpiece is reduced in comparison to the grain size in the workpiece interior. The grain size is reduced through the pressure roller in a flexing zone of the workpiece, coming from the surface of the workpiece up to 50% of the output diameter of the cylindrical workpieces in the direction of the workpiece interior. The grain size in the edge area or in the flexing zone of the workpiece is reduced to equivalent diameter of less than 100 nm. The rolled pressure roller comprises a rotating bulge that penetrates in the contact zone in the surface near area of the workpiece and is formed through a pose (9) on the surface of the workpiece. The rotating bulge penetrates in the surface near area of the workpiece and has different diameter and different depth in the surface near area of the workpiece. The pressure roller and the workpiece are moved relative to each other in a feed direction that passes in axial direction of the cylindrical workpieces. The pose is shunted on the surface of the workpiece in the feed direction before the pressure roller. The diameter of the cylindrical workpiece is reduced through the pressure roller in the contact zone, and a diameter that corresponds to output diameter of the cylindrical workpiece adopts after passing through the pressure roller. An independent claim is included for a massive cylindrical workpiece.