Manufacturing Technology of Thick-Walled Integrated Cylinder With Large-Sized Side Nozzles for Nuclear Pressure Vessel

Abstract This paper introduces a manufacturing technology of thick-walled integrated cylinder with large-sized side nozzles for nuclear reactor pressure vessel. This forging integrates the inlet nozzle and the outlet nozzle on the nozzle shell with integral flange to form an integrated forging. China First Heavy Industry (CFHI) has successfully realized the manufacturing process of this forging. During the forming stage of the forging, with the help of numerical simulation method, the size of the forging blank is reduced to the greatest extent, and a thick-walled cylinder with a convex structure is designed and forged, and then the punching guide hole is machined at the convex structure of the cylinder, which plays the role of positioning and guiding in the forging process of the side nozzle. We use special-structured forging aids to transfer the load of the forging press to the punch to complete the hot extrusion of the side nozzles, and finally realize the integrated near-net shape of the forging. The forging flow line of the forging is preserved to the greatest extent, and the best forging effect of each part of the forging is guaranteed. After the final heat treatment process of the forging, all parts of the forging obtained excellent mechanical properties.