| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
Steels for Sustainable Development III
|
| Presentation Title |
Study on the Grain Boundary Precipitation and Intergranular Fracture Behaviors in an Austenitic Fe-Mn-Al-C Lightweight Steel |
| Author(s) |
Dongwon Lee, Gun-Young Yoon, Seong-Jun Park, Jae Sang Lee, Yoon-Uk Heo |
| On-Site Speaker (Planned) |
Dongwon Lee |
| Abstract Scope |
Fe-Mn-Al-C austenitic lightweight steels have been studied for potential applications in structural materials. They can reduce energy consumption by reducing density and improving mechanical properties. However, the Fe-Mn-Al-C austenitic lightweight steels have a limitation in using their full-hardened state due to the grain boundary embrittlement after long-term aging treatment. This study investigates the formation mechanism of grain boundary precipitates during the aging treatment. The role of grain boundary precipitates in crack initiation and propagation was further studied. The alloy showed typical age-hardening behavior by forming κ-carbide but exhibited intergranular fracture after a critical aging time. TEM study revealed the sequential and detailed grain boundary segregation and precipitation mechanisms. It was confirmed that crack formation at the grain boundary precipitate under tensile stress caused the intergranular fracture and poor toughness. The detailed mechanism was discussed by ECCI and EBSD results, and first-principles calculations. |