Hot Isostatic Pressing (HIPing) has been used by Rolls-Royce to successfully manufacture nuclear pressure boundary components such as valves, piping, and pump casings. The majority of these components have been manufactured from stainless steels, typically 316L. There is considered to be potential benefits in applying the HIP process to the manufacture of large Low Alloy Steel (LAS) pressure vessels, such as ASME SA-508 Grade 4N. These advantages would include cost savings, lead-time reductions, an increase in the material quality, and improved inspectability of the as-manufactured material.

 

Applying the HIP process to LAS materials presents particular challenges due to the propensity for oxygen pick-up during the powder manufacturing stage or in subsequent filling and processing operations. The potential for oxide formation on powder particles presents a risk to the material properties being adversely affected, particularly a component’s fracture toughness which is critical to the structural integrity of safety critical nuclear pressure vessels.

 

Previously Rolls-Royce has shown it is possible to achieve enhanced tensile properties and the required Charpy impact toughness requirements. Under certain conditions, the Charpy impact toughness was found to be 66% of typical wrought material at room temperature. This paper presents tensile and Charpy impact toughness results, assesses and compares HIP material properties with forged equivalent material.


Material Properties of Hiped Sa-508

Division / Sponsors: 
Pressure Vessels & Piping (PVP)


Paper Proceedings: https://asmedigitalcollection.asme.org/PVP/PVP2020/volume/83815

PVP2020 - Virtual Conference

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.