炼钢 ›› 2016, Vol. 32 ›› Issue (4): 54-59.

• 特殊钢中夹杂物控制 • 上一篇    下一篇

稀土元素对高洁净度轴承钢中夹杂物的影响研究

  

  1. (中国科学院金属研究所 沈阳材料科学国家实验室,辽宁 沈阳 110016)
  • 接受日期:1900-01-01 出版日期:2016-08-05

Effect of RE on inclusions in highly clean bearing steel

  • Accepted:1900-01-01 Online:2016-08-05

摘要: 采用高洁净度轴承钢中加入高纯RE的方法,研究不同RE含量对高洁净度轴承钢中夹杂物的影响。借助金相显微镜、SEM、EDS和ImagePro Plus软件等观察检测和分析手段,对钢中的夹杂物进行了表征和分析。结果表明,适量RE的加入可以变质钢中的夹杂物,使得夹杂物分布更加均匀,尺寸更加细小,不规则形状的Al2O3夹杂物和条状的MnS夹杂物也变质为球状或椭球状的稀土夹杂物,从而提升高洁净度轴承钢的质量;随RE加入量的增加,夹杂物尺寸逐渐增大,形貌不规则性增强,高洁净度轴承钢的冶金质量有下降的趋势。此外,RE加入量的增加也使得夹杂物尺寸增大机制由析出型长大演化为聚合型长大。综合考虑夹杂物改性及轴承钢性能优化,高洁净度轴承钢中的最佳RE质量分数应控制在0.02 %左右。

关键词: 轴承钢, 高纯稀土, 加入量, 夹杂物, 长大机制

Abstract: Effect of different RE contents on inclusions in highly clean bearing steel was studied via adding highly pure rare earth elements. Inclusions in bearing steel were characterized and analyzed with metallographic microscopy, scanning electron microscopy, energy disperse spectroscopy and ImagePro Plus software. The results showed that a suitable amount of RE can not only make inclusions more dispersed and smaller, but also modify irregular shaped Al2O3 and strip MnS into spherical or ellipsoidal rare earth inclusions, both of which improve the quality of highly clean bearing steel. With an increase in the RE amount, inclusions gradually increase in size and their morphology becomes more and more irregular, so the metallurgical quality of highly clean bearing steel has a downward trend. In addition, increasing the RE amount causes the evoluation of main growth mechanism of inclusions from precipitationgrown to aggregationgrown. Considering inclusions modification and bearing steel performance optimization, RE mass fraction in highly clean bearing steel should be controlled around 0.02 % .

Key words: bearing steel, highly pure rare earth, adding amount, inclusion, growth mechanism