| 摘要 |
<p>A method wherein is formed by means of centrifugal casting of an either spheroid or lamellar cast iron in a forming chill-mold (1) a first annular, cylinder-shaped semi-finished product (20) by operating under controlled peripheral chill- mold speed and cooling speed conditions; the semi-finished product (20) is then subjected to a stress relieving thermal treatment or hardening, depending on the material with which it is formed, and then is subjected to machining by stock-removing on the inner diameter and on the outer diameter at a predetermined depth, holding it at either one or both of the ends (42, 43), that are finally cut at a predetermined length; further annular semi-finished products (50) are obtained, substantially cylindrical in shape, each consisting of an inner central core of the first semi-finished product (20); said second semi-finished products are then cut in the axial direction to achieve the required tangential load and in a perpendicular direction to their side walls to divide them into a plurality of slices consisting of ring-like semi-finished products (80), from each of which a sealing ring for a piston of a combustion engine is formed.</p> |
