Acta Metallurgica Sinica (English Letters)

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Optimization of Grain Boundary Character Distribution in Fe-18Cr-18Mn-0.63N High-Nitrogen Austenitic Stainless Steel

Feng SHI1), Xiaowu LI1),Yutong HU1), Chuan SU1), Chunming LIU2)   

  1. 1) Institute of Materials Physics and Chemistry, College of Sciences, Northeastern University, Shenyang 110819, China
    2) School of Materials and Metallurgy, Northeastern University, Shenyang 110819, China
  • Received:2013-05-29 Revised:2013-06-19 Online:2013-10-25 Published:2013-09-13
  • Contact: Xiaowu LI
  • Supported by:

    National Natural Science Foundation of China (Nos. 51201027 and 51271054) and Fundamental Research Funds for the Central Universities of China (Nos. N110105001, N120405001 and N120505001).

Abstract:

Grain boundary engineering (GBE) is a practice of improving resistance to grain boundary failure of the material through increasing the proportion of low ∑ coincidence site lattice (CSL) grain boundaries (special grain boundaries) in the grain boundary character distribution (GBCD). The GBCD in a cold rolled and annealed Fe-18Cr-18Mn-0.63N high-nitrogen austenitic stainless steel was analyzed by electron back scatter diffraction (EBSD). The results show that the optimization process of GBE in the conventional austenitic stainless steel cannot be well applied to this high-nitrogen austenitic stainless steel. The percentage of low ∑CSL grain boundaries could increase from 47.3 % for the solid solution treated high-nitrogen austenitic stainless steel specimen to 82.0 % for the specimen after 5 % cold rolling reduction and then annealing at 1423 K for 10 min. These special boundaries of high proportion effectively interrupt the connectivity of conventional high angle
grain boundary network and thus achieve the GBCD optimization for
the high-nitrogen austenitic stainless steel.

Key words: High nitrogen austenitic stainless steel, Grain boundary character Distribution, CSL grain boundary, EBSD