Experimental investigation on solidification of GCr15 bearing steel by the simulated continuous casting

2018 ◽  
Vol 46 (9) ◽  
pp. 801-808
Author(s):  
Jiang Danqing ◽  
Wang Rui ◽  
Zhang Qiong ◽  
Zhang Zhenqiang ◽  
Wang Baojun ◽  
...  
2019 ◽  
Vol 116 (6) ◽  
pp. 621 ◽  
Author(s):  
Hanghang An ◽  
Yan Ping Bao ◽  
Min Wang ◽  
Quan Yang ◽  
Xiang Hong Wang ◽  
...  

GCr15 bearing steel exhibits comparatively serious center macro-segregation in the continuous casting of bloom with the increase of casting speed. In the present work, the influence of complex electromagnetic stirring (M + F-EMS) and mechanical soft reduction (MSR) on the center macro-segregation in the continuous casting of 220 × 260 mm blooms of GCr15 bearing steel have been comparatively investigated to increase casting speed in order to ensure a good internal quality. Based on numerical simulation and experiments, M + F-EMS and MSR have been comprehensively evaluated and compared by combination of industrial trials. The results show that center carbon segregation first decreases and then increases with the increase of casting speed in both processes without optimization. For M + F-EMS process, when casting speed increases from 0.75 to 0.85 m · min−1, the average degree of center carbon segregation decreases from 1.2 ∼ 1.26 to 1.18 ∼ 1.25 by asymmetrical optimization; with regard to combination of M + F-EMS and MSR process, when casting speed increases from 0.75 to 0.9 m · min−1, the average degree of center carbon segregation decreases from 1.2 ∼ 1.26 to 1.08 ∼ 1.1 and the solute element distribution becomes homogeneous by optimization. In comparison, significant reduction of the center macro-segregation with the increase of casting speed can be achieved for combination of M + F-EMS and MSR process, however, it is infeasible for M + F-EMS process in the present technology situation.


2007 ◽  
Vol 201 (15) ◽  
pp. 6615-6618 ◽  
Author(s):  
Tao Sun ◽  
Langping Wang ◽  
Yonghao Yu ◽  
Yuhang Wang ◽  
Xiaofeng Wang ◽  
...  

Author(s):  
Qianren Tian ◽  
Guocheng Wang ◽  
Xinghu Yuan ◽  
Qi Wang ◽  
Seetharaman Sridhar

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-MCx 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, MCx can precipitate on the surface of TiN easily, its chemistry component consists of M3C and M7C3 (M = Fe, Cr, Mn) and Cr3C2. TiN-MCx with high TiN volume fraction, TiN forms in early stage of solidification, and MCx precipitates on TiN surface after TiN engulfed by the solidification advancing front. TiN-MCx with low TiN volume fraction, TiN and MCx form in late stage of solidification, TiN can not grow sufficiently and is covered by a large number of precipitated MCx particles.


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