Ductile cast iron articles
OwnerCharles H. Nobleinventor
Life of this patent
Estimating the term…
Abstract
Articles of manufacture in the form of an annular ductile iron piece at least a portion of which has its carbon content in the form of flattened bodies disposed in planes parallel to the central axis of the piece and normal to the outer surface of the piece, the iron grains of the piece being extended significantly both in a direction parallel to the central axis and in directions which are transverse to the central axis and parallel to planes occupied by the flattened carbon bodies, the outer surface of the piece being smooth and uninterrupted without machining and the article being free from structural failure discontinuities.
Claims6
An article of manufacture comprising an annular ductile iron piece containing
- 1-4.25% carbon,
- 1-4.25% silicon,
- 0-0.20% phosphorous, and
- at least one nodularizing agent,
- at least an axial portion of said ductile iron piece being characterized by
- having the carbon content thereof in the form of significantly flattened bodies which are predominantly disposed in planes parallel to the central axis of the piece and normal to the outer surface of the piece along the line of intersection between the plane and the outer surface, and
- by having the iron grains thereof significantly extended both in a direction parallel to the central axis of the piece and in directions which are transverse to said axis and parallel to said planes;
- said piece having a smooth uninterrupted outer surface and being free from structural failure discontinuities,
- at least said axial portion having been cold extruded through a tapered female die by applying axial pressure to the piece until the compressive yield point of the ductile iron is reached and the metal is caused to traverse the die in plastic flow while maintained under hoop compression.
Dependencies are inferred from the claim text.