Abstract
A new rolling technique has been developed at Mizushima Works for producing large H-shapes from CC slabs. While H-shapes up to 500mm in web depth and 350mm in flange width are rolled from CC beam blanks and blooms, larger H-shapes had to resort to ingot-bloomed beam blanks, at the sacrifice of product yield and quality. The new technique has proved satisfactory in rolling these larger H-shapes using CC slabs by one-heat rolling on the wide flange beam mill.
The key point of the new rolling method consists in deforming a slab into the dogbone profile by a heavy edge-rolling of a slab under a newly designed caliber with belly and a partial web rolling of the dogbone. With the following features, the new rolling process can be applied to CC stock to produce any dimensions of the existing H-shapes by one-heat rolling.
1) A 7-15 percent improvement in a raw steel to product yield, depending on H-shape dimensions.
2) Marked improvement in surface quality and internal soundness.
3) Energy saving by eliminating the ingot-making and blooming steps.
