The microstructure and hardness of martensite in Fe-C and Fe-N alloys with up to 7.5 at% contents of carbon and nitrogen, respectively, were compared. Their difference in hardness was discussed based on four strengthening mechanisms. The martensitic structures of Fe-C and Fe-N alloys with equal contents of carbon and nitrogen, respectively, were nearly identical, except for the amount of retained austenite. Furthermore, Fe-C alloy was considerably harder than Fe-N alloy. This discrepancy gradually increased with carbon and nitrogen contents. The enhanced hardness of Fe-C alloy martensite was attributed to its higher dislocation density and the stronger pinning force of interstitial carbon atoms on dislocations.
|Number of pages||8|
|Publication status||Published - Jan 1 2019|
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry