Abstract: In order to explore the influence of blanking process on the insulation of blanking surface of cast aluminum core, highprecision shearing machine was used to simulate the influence of different gaps on the section morphology and burr height of nonoriented silicon steel used for constant frequency compressor after blanking, and then the influence of different blanking process on the blue insulation of blanking surface of cast aluminum core was determined. The results showed that, as the relative clearance of blanking increased from 8 % to 18 %, the proportion of bright zone in cross section decreased from 72.5 % to 45.5 %, and the reaction time of cupric sulfate titration increased from 191 s to 232 s, and the burr height increased from 2.6 μm to 9.1 μm. The optimal die clearance of nonoriented silicon steel for constant frequency compressor should be controlled between 10 % and 15 %.

Key words: blanking process, tension annealing, clearance, burr, cast aluminum core, bluing insulation