Effect of RE on modifying inclusions in Al-killed X80 pipeline steel was studied by Ce treatment. The results show that Ce treatment modified and refined inclusions. The typical inclusions were MnS + Al₂O₃–MnS → MnS + Ce–Al–O–MnS + Ce–O–MnS → MnS + Ce–S–MnS + Ce–S + Ce–O–S–MnS + Ce–O–S → Ce–S + Ce–O–S in the sample with Ce content of 0, 0.0045, 0.018 and 0.025 wt%, respectively. With the increase in Ce content from 0 to 0.025 wt%, the mean size of inclusions decreased firstly from 2.41 to 1.80 μm and then increased to 1.87 μm, and the proportion of inclusions smaller than 2 μm gradually increased, while the proportion of inclusions larger than 3 μm decreased firstly and then increased due to the aggregation of Ce–O–S inclusions. The number density, largest size and mean size of single MnS decreased after Ce treatment.

通过Ce处理研究了稀土对Al镇静X80管线钢中夹杂物改性的影响。结果表明，Ce处理对夹杂物进行了改性和细化。典型夹杂物为 MnS + Al ₂ O ₃–MnS → MnS + Ce–Al–O–MnS + Ce–O–MnS → MnS + Ce–S–MnS + Ce–S + Ce–O–S–MnS + Ce–O–S → Ce–S + Ce Ce 含量分别为 0、0.0045、0.018 和 0.025 wt% 的样品中的 –O–S。随着 Ce 含量从 0 到 0.025 wt% 的增加，夹杂物的平​​均尺寸从 2.41 到 1.80 μm 先减小到 1.87 μm，小于 2 μm 的夹杂物的比例逐渐增加，而较大的夹杂物的比例由于 Ce-O-S 夹杂物的聚集，大于 3 μm 先减小后增大。Ce处理后，单个MnS的数量密度、最大尺寸和平均尺寸降低。