Residual stresses in arc and electron-beam welds in 130 mm thick SA508 steel: Part 1 - Manufacture

Abstract

In this study we aim to determine how the choice of welding process might impact on the through-life performance of critical nuclear components such as the reactor pressure vessel, steam generators and pressuriser in a pressurised water reactor. Attention is devoted to technologies that are currently employed in the fabrication of such components, i.e. narrow-gap variants of gas-tungsten arc welding (GTAW) and submerged arc welding (SAW), as well as a technology that might be applied in the future (electron beam welding). The residual stresses that are introduced by welding operations will have an influence on the integrity of critical components over a design lifetime that exceeds 60 years. With a view to making an assessment based on residual stress as pertinent as possible, weld test pieces were manufactured with each process at a thickness that is representative for such components, i.e. 130 mm. In Part 1, the manufacture of the welds is documented, together with the underpinning rationale, so that the value of the resulting measurements (which are presented in Part 2) will be maximised.