Cause of hole formation in the core of HR-2 alloy forging rod

There were large elongated holes near the center of the HR-2 alloy forging rod. The cause of the holes was analyzed by means of microscopic observation, energy spectrum analysis and finite element analysis. The results show that there were large inclusion defects in the process of HR-2 electro-slag remelting and the holes could not be welded in the process of pier roughening. The unwelded initial holes with large aspect ratio elongated along the drawing direction and finally formed long strip holes.