H-shaped steel production method

     H-shaped steel can be produced by welding or rolling. Welding H-shaped steel is to cut the appropriate thickness of the strip to the appropriate width, and weld the flange and web together in the continuous welding set. Welding H-shaped steel has the disadvantages of large metal consumption, difficult to ensure uniform product performance, and limited size specifications. Therefore, H-shaped steel is mainly produced by rolling method. In modern steel rolling production, the universal mill is used to roll H-shaped steel. The web plate of H-shaped steel is rolled between the upper and lower horizontal rolls, and the flange is simultaneously rolled between the side of the horizontal roll and the vertical roll. Since the flange end cannot be pressed by the universal rolling mill alone, it is necessary to set the edge rolling machine, commonly known as the edge rolling machine, behind the universal frame to give the edge of the flange and control the width of the flange. In the actual rolling operation, the two frames are used as a group to pass the rolled piece several times (Figure 2a), or the rolled piece is passed through a continuous rolling set consisting of several universal stands and one or two rolling edge end stands, and a certain amount of pressure is applied at each pass to roll the blank into the desired specification shape and size of the product. At the flange of the rolled piece, the wear of the roll is relatively large because of the sliding between the horizontal roll side and the rolled piece. In order to ensure that the roll can restore the original shape after heavy rolling, the side of the horizontal roll and the corresponding vertical roll surface of the roughing mill should be 3° ~ 8°. In order to correct the inclination of the finished flange, the finished universal rolling mill, also known as the universal finishing mill, is set up. The horizontal roll side is perpendicular to the horizontal roll line or has a small inclination Angle, generally not greater than 20 ', and the vertical roll is cylindrical.

     When the H-shaped steel is rolled by universal rolling mill, the rolling section can be extended more evenly, and the speed difference between the inner and outer roll surfaces of the flange is small, which can reduce the internal stress and appearance defects of the product. The H-shaped steel of different specifications can be obtained by changing the pressing amount of horizontal roll and vertical roll of universal rolling mill appropriately. Universal rolling mill roll shape, simple shape, long life, roll consumption can be greatly reduced. The biggest advantage of the universal rolling mill is that only the thickness of the web and flange of the same size series is changed, and the rest of the size is fixed. Therefore, the same series of H-shaped steel with the same universal pass rolling has a variety of web and flange thickness dimensions, which greatly increases the number of H-shaped steel specifications and brings great convenience for users to choose the right size specifications.

     In the absence of universal rolling mill, sometimes in order to meet the urgent need of production and construction, ordinary two-high rolling mill can also be installed with vertical roll frame to form universal pass rolling H-shaped steel. In this way rolling H-shaped steel, the product dimensional accuracy is low, the flange is difficult to be right Angle to the web, the cost is high, the specifications are few, and it is extremely difficult to roll H-shaped steel for column materials, so there are not many users.