New manufacturing techniques of large forged shell rings for pressure vessels

Abstract

A 250 ton hollow ingot was made for experimental purposes so that the properties of a large-sized hollow ingot could be simulated. The investigation results indicated that this ingot was suitable for forged shell rings of nuclear reactor pressure vessels (RPV). They were used in the manufacture of forged shell rings for an RPV of a 1300 MW type PWR and for an RPV of an 1100 MW type BWR using basic oxygen furnace, RH degassing, hollow ingot-making process. These shell rings had less segregation and clean inner surfaces which are attributed to the homogeneity of the hollow ingot.