T-bar rolling process with universal and edger mills

Abstract

Use of T-bars in shipbuilding has increased recently. As T-bars having a web height of at least twice the flange width are generally required in ships, the dimensions of existing hot-rolled T-bars are not suitable. As a result, T-bars for ships are typically fabricated by welding two plates, which is a costly and time-consuming process. To solve this problem, a new rolling method for T-bars using a combination of a universal mill and an edger mill was investigated for the production of T-bars in an actual production line. Finite element analyses of universal and edger rolling were executed to investigate the characteristics of rolling deformation including side camber. Next, multi-pass rolling experiments with a universal roughing mill and an edger mill were performed. Although straight pure lead T-bars were obtained, the web heights at the top and tail ends were larger than those of the other part. To manufacture a product with a constant web height over the whole length, side guide plates were applied in universal rolling and additional vertical rolls were applied in edger rolling. Web height deflection was eliminated by this new facility, and an excellent cross section was obtained over the entire length of the rolled T-bar. The results of this research clearly demonstrated the potential of the new rolling process for producing T-bars for ships.