ME 612 Metal Forming and Theory of Plasticity （我612金属成形和塑性理论）.pdfVIP

ME 612 Metal Forming and Theory of Plasticity 16. Cold Rolling of Strip Yrd.Doç.Dr. Ahmet Zafer Şenalp e‐mail: azsenalp@gyte.edu.tr Makine Mühendisliği Bölümü Gebze Yüksek Teknoloji Enstitüsü 16. Cold Rolling of Strip A theory of rolling aims at relating the externally applied forces to the mechanical  strength properties of the material rolled. Any such theory will be of especial value in  estimating the power requirements of a rolling mill for use on a newly developed  metal or alloy. Rolling theory may be divided into two main parts, that which applies to hot‐rolling and that which applies to cold‐rolling. In hot‐rolling, the yield stress characteristic of the metal is strain‐rate dependent and the frictional force between the rolls and stock is high, whereas in the cold‐rolling of strip the yield stress characteristics of the metal is essentially independent of the rate of deformation, and the frictional force between rolls and stock is low. We shall confine ourselves here to the cold‐rolling of strip and in order to obtain a solution, we shall have to restrict further the scope of the theory. The assumptions that will be made are those set down by VON KARMAN (1925) and used by OROWAN (1943). BLAND and FORD (1948), basing their work on Orowans theory, made further assumptions, and it is on their work that the following solution is based. Dr. Ahmet Zafer Şenalp           GYTE‐Makine Mühendisliği Bölümü 2 ME 612 16. Cold Rolling of Strip Consider what happens when a strip of material of initial thickness h , enters the rolls,