The effect of ultrasonic nano crystal surface modification for mitigation of the residual stress after weld inlay on the alloy 82/182 dissimilar metal welds of reactor vessel in/outlet nozzles

Cho, Hong Seok; Park, Ik Keun; Jung, Kwang Woon

doi:2015.33.2.40

J Weld Join > Volume 33(2); 2015 > Article

Research Paper

Journal of Welding and Joining 2015;33(2):40-46.
DOI: https://doi.org/10.5781/JWJ.2015.33.2.40 Published online April 30, 2015.

The effect of ultrasonic nano crystal surface modification for mitigation of the residual stress after weld inlay on the alloy 82/182 dissimilar metal welds of reactor vessel in/outlet nozzles

Hong Seok Cho^*, Ik Keun Park^**, Kwang Woon Jung^***

Correspondence: Kwang Woon Jung,
Email: jungkw99@kps.co.kr

Abstract

This study was performed to investigate the effect of ultrasonic nano crystal surface modification (UNSM)on residual stress mitigation after Weld Inlay repair for butt dissimilar metal weld with Alloy 82/182 in reactor vessel In/Outlet nozzle. As-welded and Weld Inlay specimens were made in accordance with design standard of ASME Code Case N-766, and two planes of their weld specimens were peened by the optimum UNSM process condition. Peening characteristics for weld specimens after UNSM treatment were evaluated by surface roughness and Vickers hardness test. And, residual stress for weld specimens developed from before and after UNSM treatment was measured and evaluated by instrumented indentation technique. Consequently, it was revealed that the mitigation of residual stress in weld metal after Weld Inlay repair of reactor vessel In/Outlet nozzle could be possible through UNSM treatment.

Key Words: Reactor vessel nozzle, Alloy 82/182, PWSCC, Weld Inlay, UNSM, Residual stress