Complex Precipitates of TiN-MC<em>_x</em> in GCr15 Bearing Steel

• Main Authors: Qianren Tian, Guocheng Wang, Xinghu Yuan, Qi Wang, Seetharaman Sridhar
• Format: Article
• Language: English
• Published: MDPI AG 2019-06-01
• Series: Metals
• Subjects: non-aqueous electrolysis; TiN-MC<i>_x</i>; precipitation; bearings; high carbon chromium bearing steel
• Online Access: https://www.mdpi.com/2075-4701/9/6/641

Nitride and carbide are the second phases which play an important role in the performance of bearing steel, and their precipitation behavior is complicated. In this study, TiN-MC<i>_x</i>precipitations in GCr15 bearing steels were obtained by non-aqueous electrolysis, and their precipitation mechanisms were studied. TiN is the effective heterogeneous nucleation site for Fe₇C₃ and Fe₃C; therefore, MC<i>_x</i>can precipitate on the surface of TiN easily. The chemistry component of MC<i>_x</i> consists of M₃C and M₇C₃ (M = Fe, Cr, Mn) and Cr₃C₂. TiN-MC<i>_x</i> with high TiN volume fraction, TiN forms in early stage of solidification, and MC<i>_x</i> precipitates on TiN surface after TiN engulfed by the solidification advancing front. TiN-MC<i>_x</i> with low TiN volume fraction, TiN and MC<i>_x</i> form in late stage of solidification, TiN can not grow sufficiently and is covered by numerous precipitated MC<i>_x</i>particles.