|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||2016 Technical Division Student Poster Competition
||SPG-56: Synchrotron Study on the Thermal Stability of Retained Austenite in High-carbon Chromium Steels
||Wen Cui, David San Martín, Pedro Rivera-Díaz-del-Castilloa
|On-Site Speaker (Planned)
Martensitic bearing steels display a high carbon concentration of about 1 wt%; this is consistent with large amounts of retained austenite (RA) ranging 1-20 vol%. Being metastable, RA decomposition can be triggered by high temperatures, resulting in altered microstructures and properties. This could influence bearing performance and its lifetime. Understanding the thermal stability of RA is therefore essential for bearing service.
Synchrotron experiments have been conducted to investigate in situ the thermal stability of martensitic 100Cr6 and a modified grade (100Cr6M). The evolution of phase fraction, lattice parameters and carbon concentrations at elevated temperatures has been characterised. Results show that RA decomposition occurs across all samples, with more energy required for those present in 100Cr6M. Moreover, RA of different stabilities has been detected in 100Cr6M, which is likely from different carbon concentration. In addition, martensite recovery is detected from the change in the symmetrical character of diffracted peaks.
||Definite: None Selected