Revealing heterogeneous C partitioning in a medium Mn steel by nanoindentation

Abstract

The present work employs nano-indentation technique to investigate the C partitioning in a medium Mn steel subjected to quenching and tempering process. It is found that the C partitioning between martensite and austenite is inhomogeneous. Particularly, the large lenticular martensite has negligible C partitioning into the austenitic matrix as it maintains an ultra-high nanohardness comparable to the one without tempering. Strategies to suppress the formation of large martensite are discussed.

Keywords:

• Martensite
• Austenite
• Nanohardness
• Medium Mn steel
• Quenching and partitioning

Acknowledgements

M. X. Huang acknowledges the support from the Steel Joint Funds of the National Natural Science Foundation of China (Grant No. U1560204), National Science Foundation of China (Grants No. 51301148), Research Grants Council of Hong Kong (Grants No. HKU719712E, HKU712713E) and Small Project Funding of HKU (Grant No. 201409176053); University Research Committee, University of Hong Kong.