Work

Microstructure Evolution and Modelling During Tempering Heat Treatment at 670 °C in 9–12 wt.% Cr Ferritic/Martensitic Heat-Resistant Steel

Year: 2025

Type: article

Abstract: This study aimed to investigate the growth behavior of key precipitates in 9–12 wt.% Cr ferritic/martensitic heat-resistant steel as a function of tempering duration. Tempering was carried out at 670 °C for durations between 1 h and 300 h. The precipitates identified were M23C6, Laves phase, Nb-rich MX, and V-rich MX, each exhibiting distinct growth behavior with increasing tempering time. Transmission electron microscopy (TEM) was used to quantitatively analyze their growth behavior. The results revealed that M23C6, Laves phase, and V-rich MX underwent progressive coarsening with time, whereas Nb-rich MX showed negligible growth even after prolonged tempering. Based on the quantified data, a precipitate-growth model was implemented in MatCalc, and the key parameters were derived and validated against experimental data. The modeling results showed excellent agreement with experimental observations, confirming that the proposed model can reliably predict the microstructural evolution of ferritic/martensitic heat-resistant steel under long-term high-temperature exposure relevant to USC applications.

Source: Metals

DOI: 10.3390/met15121350

Authors: Bong Cheon Park, Sung-Dae Kim, Ihho Park, Jae Hoon Jang, Namhyun Kang

Institutions: Korea Institute of Materials Science, Pusan National University, Pukyong National University, Dong-A University

Language: English

Topic: High Temperature Alloys and Creep

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,137

Funders: Dong-A University, Ministry of Trade, Industry and Energy, Korea Institute of Materials Science