On the Material Properties of a Large PM+HIP Component for Application in Nuclear Power Plants

Elaboration of Nuclear Power Plant (NPP) pipework currently relies on forging/casting and machining processes. However, to maintain performance and competitiveness, Framatome and EDF launched a pre-industrialisation project to demonstrate the ability of HIP and the supply-chain to produce a 8-ton 304L primary elbow in compliance with the nuclear requirements. The final elbow was supplied by Framatome with EDF with Bodycote performing the elbow casing design and the HIP process. The characterisation results confirm its compliance with EDF/Framatome’s requirements, based on current RCC-M code requirements for forged 304L: notably a fine microstructure and strong mechanical properties. They are also homogeneous across the whole elbow. Welding tests show the good weldability of HIP 304L. This large-scale demonstrator shows that the developed HIP process has sufficient maturity for a standardised industrial use in the nuclear industry to provide large homogeneous components with compliant material properties, that can be installed in NPPs.