Development of Optimum Size Control in H-Shapes Rolling

Abstract

In conventional H-shapes, the inner dimensions are fixed because the roll dimensions cannot be varied during rolling.However, from the viewpoint of economy and on-site productivity in construction work, rolled H-shapes with fixed outer dimensions(web depth, flange width)have been strongly required. Newly developed hot rolling techniques make it possible to produce such H-shapes with quality equal to that of welded H-shapes.
Using an experimental model mill, it was found that a web width reducing method using a universal mill can produce a constant web depth with different flange thicknesses. At the same time, it is possible to prevent web buckling, web off-center, and nonunifomity of the web thickness, which have been the main problems in web width reduction. It was also found through model rolling experiments that grooveless edger rolling is effective in controlling the flange width. Using these techniques, it is possible to manufacture H-shapes with substantially more accurate fixed outer dimensions than those produced by conventional rolling.