Forging components for pressure vessels issued from conventional ingots may present some inconveniences, such as an important waste of metal and metallurgical problems induced by segregation.
Le Creusot Heavy Forge has developed three new types of ingots specially adapted to these components: Type 1. Ingots with vertical-oriented solidification and low height/diameter ratio for manufacturing flat components. Type 2. Ingots with horizontal-oriented solidification for manufacturing hollow forgings with a noncladded inner surface. Type 3. Cylindrical hollow ingots for hollow forgings, the inner face of which has to be cladded.
The mode of solidification and the location of macrosegregation areas of each new ingot type are described.
Three examples of components manufactured from these new ingot types are presented: 1. A head for a 1300-MW pressurized water reactor (PWR) pressure vessel forged from a Type 1 ingot. 2. A prototype shell forging in 2¼Cr-1Mo steel for the petrochemical industry issued from a Type 2 ingot. 3. A B shell for a 1400-MW French nuclear reactor issued from a hollow ingot.