Microstructural refinement in an ultra-high strength martensitic steel via equal channel angular pressing

作者：Gibbons S L^*; Abrahams R A; Vaughan M W; Barber R E; Harris R C; Arroyave R; Karaman I

来源：Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 2018, 725: 57-64.

DOI：10.1016/j.msea.2018.04.005

• CALPHAD
• Ultra-high strength steel
• Equal channel angular pressing
• Grain refinement
• Martensitic steel

In this work, a CALPHAD thermodynamic model is used to assess the thermodynamic stability of austenite in an Ultra-High Strength Martensitic Steel (i.e., Eglin Steel) in order to refine parent austenite-grain sizes, via high temperature equal-channel angular pressing (ECAP). The parent austenite-grain sizes are reduced from 188 mu m to 14.8 mu m, which in turn, led to the refinement of martensite lath sizes. This approach produced a yield strength of 1.68 GPa, ultimate strength of 1.98 GPa, and an elongation of 16.1%. Overall, this method reduced development cycle times and achieved alloy performance on par with Ni-Co secondary hardening steels.

• 出版日期2018-5-16