抄録
In manufacturing of the I-beam steel directly from the small ingot in one heat without billeting, they are often annoyed by the seamy defects on its flange edges. For prevention of the seamy defects, the authors began to study the various factors of their occurence in both steelmaking and rolling.
At first they investigated the surface deformation of I-beam by rolling the experimental ingot on which was drilled many small holes and found that the holes situated within 35mm from the corner of ingot became the source of seamy defects of flange edges.
So the subsurface blow holes of the ingot corners were assumed by counting number of them at adjacent chipping lines and the correlation between skinholes vs. seamy defects was found.
The experimental ingot was rolled on which was drilled thousand or more small holes with varying diameter and depth around the ingot and the length and number of artificial defects were measured.
Then the authors showed the effects of diameter and depth of artificial blow holes on the length and percentages of occurence of artificial defects.
