Abstract
It is considered that surface defects of steel products such as round bars and sections have been depended on the skin blowholes of ingots originating from steel making and teeming process.
There are some kinds of the steel products on which seamy defects appear easily during rolling operation while others do not, and in the case of each steel products, there are specific. parts on which seamy defects appear easily.
In order to solve such practical problems, the author pursued the relation between surface defects of ingot and that of various steel products by means of artificial blowholes.
The results were as follows:
The seamy defects on various round bars and sections tended to appear severely on the parts which correspond to the wider side of the rectangular cross section of the ingot and their development was much affected by the initial roughing conditions.
