I-section Steel is mainly divided into ordinary I-shaped steel, light I-shaped steel and wide-wing I-shaped steel. According to the height ratio of flange and web, it is divided into wide-width, medium-width, narrow-width wide-width I-width steel. The specifications produced by the first two are 10-60, that is, the corresponding height is 10 cm-60 cm. At the same height, the lightweight I-shaped steel has narrow flanges, thin webs and light weight. Wide flange I-shaped steel, also known as H-shaped steel, has a cross-sectional feature that the legs are parallel and there is no inclination on the inner side of the legs. It is an economic section steel and is rolled on a four-roll universal rolling mill, so it is also called "universal I-shaped steel". Ordinary I-shaped steel and light I-shaped steel have formed national standards. The specifications of I-shaped steel are expressed by the centimeter value of waist width, such as I-shaped steel with a waist width of 10 cm. The types of I-shaped steel include hot rolled ordinary I-shaped steel, light I-shaped steel and wide parallel-leg I-shaped steel (H-shaped steel). The waist width of hot-rolled ordinary I-shaped steel in my country is 100-630mm, which is expressed as No.10-No.63, and the inclination of the inner wall of the legs is 1:6. The hole-type systems for rolling I-steel include direct-rolled hole-type systems, oblique-rolled hole-type systems and mixed hole-type systems. In addition, I-shaped steel can also adopt special rolling method. (1) Direct rolling hole type system. A straight-rolled hole-type system refers to a hole-type system in which the two open legs of the I-shaped steel hole-type are on the same side of the roll axis at the same time, and the waist is parallel to the roll axis. Its advantages are that the roller has a small axial force, a small axial movement, no working slope is required, and the hole type occupies a small roller body length. Under the condition of a certain roller body length, multiple hole types can be equipped. (2) Inclined-rolled hole type system. This type of hole system refers to the two open legs of the I-shaped steel hole type that are not on the same side of the waist at the same time, and the waist has an angle with the horizontal axis. (3) Hybrid hole type system. According to the characteristics of the rolling mill and the product, in order to give full play to the advantages of their respective systems and overcome their shortcomings, a hybrid pore-type system is often used, that is, a combination of two or more systems. For example, the finished product hole and the front hole of the finished product adopt a straight leg oblique hole rolling system, and other hole types adopt a bending leg oblique rolling system; or the rough rolling hole adopts a straight leg oblique hole, and the last 3 to 4 fine rolling holes adopt a straight leg oblique hole, etc. (4) Special rolling method. For some reason, when it is difficult to roll out the required I-shaped steel by using the usual rolling method, a special rolling method can be used to make full use of the techniques of uneven deformation and hole design. For example, when the billet has a narrow cross-section and requires the rolling of a wider I-shaped steel, a wave rolling method can be used; if the billet has a wider cross-section and requires the rolling of a smaller I-shaped steel, a negative wide-stretch rolling can be used. Application Features Report Edit I-shaped steel, whether ordinary or light, has a relatively high and narrow cross-sectional dimensions, so the moment of inertia of the two main shafts of the cross-section is large, so it can only be used directly for components that are bent in the web plane or form lattice stress-bearing members. It is not suitable to use axial compressed members or components that are perpendicular to the web plane, which makes it very limited in its application range. I-shaped steel is widely used in construction or other metal structures. Ordinary I-shaped steel and lightweight I-shaped steel have relatively high and narrow cross-sectional dimensions, so the moment of inertia of the two spindles in the cross-section has a large difference, which makes it have a range of application.
