Abstract: With the extension of high temperature diffusion time,the width of the carbide strip increases and the carbide particles become fine.According to the existing SEP 1520- 1998,CB/T 18254-2016 and ISO 5949- 1983 standard charts, the longer the diffusion time,the higher theband rating,which is contrary to the effect of improving process execution.In this papera new carbide band evaluation method is used to complete the carbide band rating based on the size of the carbide particles in the band,the evaluation results show that the longer high temperature diffusion time,the lower the corresponding carbide band rating.this method can more clearly,intuitively and scientifically proves the improvement of carbide particle refinement and distribution uniformity brought about by the improvement of high temperature diffusion.

Key words: High Carbon Chromium Bearing Steel, Carbide Band, Carbide Particle, Rating Standard

摘要： 随着高碳铬轴承钢高温扩散时间的延长，碳化物带状的宽度会随之增加，碳化物颗粒变得细小。但按现有的SEP 1520-1998、GB/T 18254-2016及ISO 5949-1983标准图谱进行评级时，存在高温扩散时间越长，带状评级越高的情况，与改善工艺执行的效果相悖。本文采用一种新的碳化物带状评定方法，以带状内碳化物颗粒的尺寸为依据，完成碳化物带状评级，评定结果显示，高温扩散时间越长，所对应的碳化物带状级别越低，说明该方法可更清晰、直观及科学的回归反馈高温扩散改善带来的碳化物颗粒细化及分布均匀性的改善。

关键词: 高碳铬轴承钢, 碳化物带状, 碳化物颗粒, 评级标准