Applicability analysis of induction bending process to P91 piping of PGSFR by high-temperature creep tests

This study evaluated the high-temperature creep structural integrity of P91 induction-bent piping for Prototype Gen-IV Sodium-cooled Fast Reactors (PGSFR) through specimen creep tests and bent pipe structural creep test alongside inelastic analysis. Specimen creep tests at 550 °C showed results that significantly exceeded the creep rupture life requirements by the ASME Code. EBSD analysis confirmed that Kernel Average Misorientation (KAM) values quantitatively reflect creep damage evolution; KAM values measured after the bent piping structural test (550 °C, 72 kN) remained below those of ruptured specimens, indicating preserved structural integrity. Inelastic analysis using Chaboche combined hardening model and Combined Time Hardening (CTH) creep model accurately simulated experimental behaviors, and evaluations per ASME HBB-T-1400 and HBB-T-1310 satisfied creep damage and inelastic strain limit criteria. Consequently, this study rigorously validated the applicability of induction-bent P91 piping to SFR plants through both experimental and analytical methods.