SEDL / STP / STP903-EB / STP17363S

18—18 Corrosion-Resistant Retaining Rings for Nuclear Power Plant Generators

Rambaud, JB
Technical manager, Usinor, Paris,

Cazenave, RH
Chief metallurgist, Pamiers Plant, Compagnie Française de Forges et Fonderies, Pamiers,

Pages: 15    Published: Jan 1986

Download this paper for $25 PDF (324K)          View License Agreement
Abstract

Several years ago, the Pamiers Plant of the Compagnie Française de Forges et Fonderies (C3F) undertook a research program on the 18-18 corrosion-resistant grade for retaining rings.

An extensive testing program conducted in association with Electricite de France led to a decision to equip the 900- and 1300-MW generators of French nuclear power plants with NMF 18 retaining rings (NMF 18 is the C3F trademark for the 18-18 material).

To date, 20 rings have been manufactured in the following sizes: 1. Outer diameter: 1746 to 2040 mm (68.74 to 80.31 in.). 2. Thickness: 83 to 90 mm (3.27 to 3.74 in.). 3. Height: 700 to 775 mm (27.56 to 30.51 in.). 4. Weight: 2.5 to 3.5 metric tons.

The guaranteed yield strength at midwall is 750, 850, or 900 MPa (109, 123, or 130 ksi), depending on the type of ring.

After a review: (a) of the properties of the 18-18 grade and their comparison with the conventional 18-4 material and (b) of the principal results of the test program, we are describing the specifics of the manufacturing process and the facilities of these large rings.