Analysis on Domestic and International Standards for Determination of Non-metallic Inclusions in Steels

The main domestic and international standards for determination of non-metallic inclusions in steels were introduced, analyzed and compared. The results show that there were a lot of standards for determination of non-metallic inclusions, but the evaluation methods could be classified into two categories, namely, the worst field method and the average field method. The former could be applicable to the conventional detection of inclusions, and the latter could be suitable for the detection of inclusions in steel for special important part or with high purity. However, for the same field of view, the contents of non-metallic inclusions evaluated according to different standards were basically consistent.