Classification and detailed explanation of steel sections

Classification

According to the different smelting quality of steel, steel is divided into ordinary steel and high-quality steel. Ordinary steel is divided into large steel, medium steel and small steel according to the current metal product catalog. Ordinary steel can be divided into I-beam, channel steel, angle steel, round steel, etc. according to its cross-sectional shape.

Large steel: I-beam, channel steel, angle steel and flat steel in large steel are all hot-rolled. Round steel, square steel and hexagonal steel are forged and cold-drawn in addition to hot rolling.

I-beam, channel steel and angle steel are widely used in industrial buildings and metal structures, such as factories, bridges, ships, agricultural machinery and vehicle manufacturing, transmission towers, and transportation machinery, and are often used in combination. Flat steel is used as bridges, house frames, fences, transmission ships, vehicles, etc. in construction sites. Round steel and square steel are used as various mechanical parts, agricultural machinery accessories, tools, etc.

Medium steel: I-beam, channel steel, angle steel, round steel and flat steel in medium steel are similar in use to large steel.

Small steel: Small steel includes angle, round, square and flat steel. Its processing and use are similar to those of large steel. Small diameter round steel is often used as construction reinforcement.

Features

Application features of H-shaped steel

Hot-rolled H-shaped steel rationally distributes the height-to-width ratio of the cross-section size according to different uses, and has excellent mechanical properties and superior performance.

Flexible and rich design style. Under the same beam height, the bay of the steel structure can be 50% larger than that of the concrete structure, making the building layout more flexible.

Light weight of the structure. Compared with the self-weight of the concrete structure, the reduction of the self-weight of the structure reduces the internal force of the structural design, which can make the foundation treatment requirements of the building structure low, the construction is simple, and the cost is reduced.

The steel structure mainly based on hot-rolled H-shaped steel has a scientific and reasonable structure, good plasticity and flexibility, high structural stability, and is suitable for building structures that withstand large vibration and impact loads. It has strong resistance to natural disasters and is particularly suitable for building structures in some earthquake-prone areas. According to statistics, in the world's devastating earthquake disasters of magnitude 7 or above, steel structure buildings mainly based on H-shaped steel suffered the least damage.

Increase the effective use area of the structure. Compared with concrete structures, steel structure columns have a small cross-sectional area, which can increase the effective use area of the building. Depending on the different forms of the building, the effective use area can be increased by 4-6%.

Compared with welded H-shaped steel, it can significantly save labor and materials, reduce the consumption of raw materials, energy and labor, have low residual stress, and good appearance and surface quality.

It is convenient for mechanical processing, structural connection and installation, and is also easy to dismantle and reuse.

The use of H-shaped steel can effectively protect the environment, which is specifically manifested in three aspects: First, compared with concrete, dry construction can be used, which produces less noise and less dust; second, due to the reduced deadweight, the amount of soil taken for foundation construction is small, and the damage to land resources is small. In addition, the amount of concrete is greatly reduced, and the amount of mountain excavation and stone excavation is reduced, which is conducive to the protection of the ecological environment; third, after the service life of the building structure expires and the structure is dismantled, the amount of solid waste generated is small, and the recycling value of scrap steel resources is high.

The steel structure mainly based on hot-rolled H-shaped steel has a high degree of industrialization, is convenient for mechanical manufacturing, intensive production, high precision, convenient installation, and easy quality assurance. It can be built into a real house manufacturing factory, bridge manufacturing factory, industrial plant manufacturing factory, etc. The development of steel structure has created and driven the development of hundreds of emerging industries.

The construction speed is fast, the floor space is small, and it is suitable for all-weather construction and is less affected by climatic conditions. The construction speed of steel structure made of hot-rolled H-shaped steel is about 2-3 times that of concrete structure, and the capital turnover rate is doubled, which reduces financial expenses and saves investment. Taking the "Jinmao Tower" in Pudong, Shanghai, my country as an example, the main structure of the nearly 400 m high structure was completed in less than half a year, while the steel-concrete structure requires two years.

Application characteristics of angle steel

Angle steel: commonly known as angle iron, is a long steel strip with two sides perpendicular to each other. There are equal angle steel and unequal angle steel. The two sides of equal angle steel are equal in width, and its specifications are expressed in millimeters of side width × side width × side thickness. For example, "∠30×30×3" means an equal angle steel with a side width of 30 mm and a side thickness of 3 mm. It can also be expressed by model, which is the number of centimeters of the side width, such as ∠3#. The model does not indicate the size of different side thicknesses in the same model, so the side width and side thickness of the angle steel should be filled in in the contract and other documents to avoid using the model alone. The specifications of hot-rolled equal angle steel are 2#-20#. Angle steel can be used to form various load-bearing components according to different structural needs, and can also be used as connectors between components. It is widely used in various building structures and engineering structures, such as beams, bridges, transmission towers, lifting and transportation machinery, ships, industrial furnaces, reaction towers, container racks, and warehouse shelves.

Channel steel application features

Channel steel is a long steel strip with a groove-shaped cross section. Its specification is expressed in the form of 120*53*5, which means a channel steel with a waist height of 120 mm, a leg width of 53 mm, and a waist thickness of 5 mm, or 12# channel steel. Channel steels with the same waist height, if they have different leg widths and waist thicknesses, also need to be distinguished by adding a b c to the right of the model, such as 25a# 25b# 25c#, etc. Channel steel is divided into ordinary channel steel and light channel steel. The specifications of hot-rolled ordinary channel steel are 5-40#. The specifications of hot-rolled variable channel steel supplied by agreement between the supply and demand parties are 6.5-30#. Channel steel is mainly used in building structures, vehicle manufacturing and other industrial structures, and channel steel is often used in conjunction with I-beams.

Application characteristics of I-beams

I-beams, also known as steel beams, are long strips of steel with an I-shaped cross section. Its specifications are expressed in millimeters of waist height (h)*leg width (b)*waist thickness (d), such as "I160*88*6", which means an I-beam with a waist height of 160 mm, a leg width of 88 mm, and a waist thickness of 6 mm. The specifications of I-beams can also be expressed by model numbers, which indicate the number of centimeters of waist height, such as I16#. If there are several different leg widths and waist thicknesses for I-beams with the same waist height, a b c should be added to the right of the model number to distinguish them, such as 32a# 32b# 32c#, etc. I-beams are divided into ordinary I-beams and light I-beams. The specifications of hot-rolled ordinary I-beams are 10-63#. The specifications of hot-rolled ordinary I-beams supplied by agreement between the supply and demand parties are 12-55#. I-beams are widely used in various building structures, bridges, vehicles, brackets, machinery, etc.

Application characteristics of cold-formed steel

Cold-formed steel is the main material for making light steel structures. It is made by cold-forming steel plates or steel strips. Its wall thickness can not only be made very thin, but also greatly simplifies the production process and improves production efficiency. It can produce various profiles with uniform wall thickness but complex cross-sectional shapes and cold-formed steel of different materials that are difficult to produce by general hot rolling methods. In addition to being used in various building structures, cold-formed steel is also widely used in vehicle manufacturing, agricultural machinery manufacturing, etc.

Special-shaped steel includes retaining rings, horseshoe steel, magnetic pole steel, presser foot, shallow channel steel, small channel steel, T-shaped steel, ball flat steel, feed tooth steel, hot-rolled hexagonal steel, etc. In addition, there are rivet steel, farm tool steel, and window frame steel.