H-beams can be manufactured either by welding or rolling. When produced through welding, strips of appropriate thickness and width are cut and then welded together to form the flanges and web on a continuous welding unit. However, this method tends to consume more metal, making it challenging to ensure consistent product performance, and the range of available sizes is limited. As such, the majority of H-beams are manufactured via the rolling process. In contemporary steel production, universal rolling mills are commonly used to roll H-beams. During this process, the web is rolled between the upper and lower horizontal rolls, while the flanges are simultaneously shaped between the side of the horizontal roll and the vertical roll. Due to the limitations of the universal rolling mill, an edge rolling machine, often referred to as an edger stand, is placed behind the main setup to help press down the flange edges and control their width.
In practical operations, the two stands are typically used as a pair, with the material being passed back and forth multiple times (as shown in Fig. 2a) or through a series of universal stands followed by one or two edger stands. Each pass in the continuous rolling line involves a specific reduction amount, gradually transforming the billet into the desired shape and size. At the flange portion of the rolled piece, the contact between the side of the horizontal roll and the material causes significant wear. To ensure that the rolls can be restored to their original condition after intensive use, the sides of the upper and lower horizontal rolls in the roughing mill and the corresponding vertical rolls are slightly inclined at angles ranging from 3° to 8°. Additionally, a finishing universal rolling mill, also known as a universal finishing mill, is employed to adjust the inclination angle of the finished flange. The side of the horizontal roll is kept perpendicular to its axis or has a slight inclination angle, usually no more than 20', while the vertical roll remains cylindrical (Fig. 2d).
Rolling H-beams using a universal rolling mill ensures a more uniform extension of the cross-section, minimizing the speed difference between the inner and outer surfaces of the flange. This helps reduce internal stress and surface defects in the final product. By adjusting the reduction amounts of the horizontal and vertical rolls in the universal rolling mill, various H-beam specifications can be achieved. The simplicity of the roll design contributes to its durability and reduces roll consumption. The primary advantage of this method lies in its versatility within the same dimension series; only the thickness of the web and flange is altered, while other dimensions remain constant. Consequently, a single universal pass can produce multiple web and flange thickness specifications, significantly increasing the number of available H-beam options and offering greater flexibility for users.
In situations where a universal rolling mill is unavailable, an alternative approach involves adding a vertical roll frame to a standard two-high rolling mill to create a universal pass for H-beam production. While this method can meet immediate production demands, it suffers from low dimensional accuracy, difficulty in achieving a perfect right angle between the flange and web, high costs, and limited specification ranges. Moreover, rolling H-beams suitable for columns proves exceptionally challenging, leading to limited user adoption. Despite these drawbacks, this technique remains viable in certain scenarios where resources or time constraints make it the only feasible option.