March 2026

Conference Paper

Characterization of Precipitation-Strengthening Heat-Resistant Austenitic Stainless Steels for Life-Prediction Modeling

By:
Yamamoto, Yukinori ; Ren, Qingqiang ; Pillai, Rishi R; Hoelzer, David T; Brady, Michael P; Zhao, Yajie ; Poplawsky, Jonathan D; Lara-Curzio, Edgar ; Mariyappan, Arul Kumar; Lebensohn, Ricardo; Capolungo, Laurent; Glazoff, Michael; Gao, Michael; Detrois, Martin; Jablonski, Paul; Hawk, Jeffrey
Page Number:
1240-1248
Book Title:
Advances in Materials, Manufacturing, and Repair for Power Plants: Proceedings from the Tenth International Conference
Publication Date:
March 12, 2026
Publisher Location:
ASM International, Ohio, United States of America
Conference Name:
10th International Conference on Advances in Materials, Manufacturing & Repair for Power Plants
Conference Location:
Bonita Springs, Florida, United States of America
Conference Sponsor:
ASM International, EPRI
View DOI Listing:
https://doi.org/10.31399/asm.cp.am-epri-2024p1240

Abstract

In this study, the role of minor alloying additions in 347H stainless steels (UNS34709, ASTM A240/240M) on creep-rupture properties at 650-750°C and microstructure evolution during isothermal exposure at 750°C has been investigated, aiming to provide the experimental dataset as boundary conditions of physics-based modeling for material/component life prediction. Four different 347H heats containing various amounts of boron and nitrogen additions were prepared and evaluated. The combined additions of B and N are found to stabilize the strengthening secondary M23C6 carbides and retarding the transition from M23C6 to sigma phase precipitates during thermal exposure. The observed kinetics of microstructure evolution reasonably explains the improvement of creep-rupture properties of 347H stainless steels with the B and N additions.