Steel knowledge: profiles

1. Classification of profiles 1. Simple section steel

①square steel——hot-rolled square steel, cold-drawn square steel;

②round steel——hot-rolled round steel, forged round steel, cold-drawn round steel

③wire rod;

④flat steel;

⑤spring flat steel;

⑥ Angle steel-equilateral angle steel, unequal angle steel;

⑦ triangle steel

⑧ hexagonal steel;

⑨ bow steel;

⑩ oval steel

2. Complex section steel

① I-beam-ordinary I-beam, light I-beam

② channel steel-hot-rolled channel steel (ordinary channel steel, light channel steel), curved channel steel

③ H-beam (also known as wide-leg I-beam )

④ Rails-heavy rail, light rail, crane rails, other special steel rails

⑤ window frame steel

⑥ steel sheet pile

⑦ curved section steel-cold-formed steel, hot-formed steel

⑧ other two, large, medium and small section steel division of
large and
medium
Small
I-beam
height≥180mm
height＜180mm
channel steel
height≥180mm
height＜180mm
equilateral angle steel
side
width≥160mm
side width 50-140mm side width 20-45mm
unequal side angle steel
side width ≥160×100mm
side width 140×90 -50×32 mm
side width ≤45×28 mm
round steel
diameter ≥90mm
diameter 38-80mm
diameter 10-36 mm
square steel
side width ≥90mm
side width 50-75 mm
side width 10-25 mm
flat steel
width ≥120mm
width 60-100 mm
wide 12-55 mm
rebar
Diameter ≥40 mm
Diameter 10-36 mm
Rivet steel
Diameter 10-22 mm
Other
special-shaped steel: special-shaped steel such as track shoes, steel sheet piles
, composite flat steel for small farm tools
, agricultural tool steel, window frame steel, etc.
3. Hot rolled Ribbed steel bar
1. The grades of hot-rolled ribbed steel bars are composed of HRB and the minimum yield point of the grades. H, R, and B are the first letters of the three words: Hotrolled, Ribbed, and Bars respectively. Hot-rolled ribbed steel bars are divided into three grades: HRB335 (the old grade is 20MnSi), HRB400 (the old grade is 20MnSiV, 20MnSiNb, 20MnTi), and HRB500. 2. Vanadium-containing grade III threaded steel bars ①The market prospect of vanadium-containing grade III threaded steel bars is broad , Has the advantages of high strength, good toughness, good welding performance and seismic performance. In the construction market of developed countries such as Europe, Grade III rebars account for 80% of the total rebar. Countries such as the United Kingdom, Germany, Australia, Japan and other countries have used high-strength vanadium-containing Grade III rebars to reach 80-90%. In 1995, the former Ministry of Metallurgy and the Ministry of Construction jointly issued a document for promotion and application. The Ministry of Construction incorporated the technical conditions of the new grade III rebar into the national standard GBJ10-89 “Specification for Design of Concrete Structures”, which came into effect on January 1, 1997. Grade III rebar has been successfully applied in high-rise buildings, large power stations, bridges, tunnels, airports and other engineering projects, and has a broad market prospect. The Ministry of Construction requires the consumption of new grade III steel bars to reach 50% of the total rebar in 2002 and 80% at the end of the “Tenth Five-Year Plan” period. However, due to insufficient publicity and promotion, and the amount of use is much lower than the old grade II 335Mpa ordinary grade rebar, so it is necessary to vigorously promote and promote the new grade III rebar. ②Advantages of vanadium-containing grade III threaded steel bars A. Economy: Due to the high strength, the use of new grade III threaded steel bars can save 10-15% of steel compared to grade II threaded steel bars, so the construction cost of construction projects can be reduced. B. High strength and good toughness: using microalloying treatment, the yield point is above 400Mpa, and the tensile strength is above 570Mpa, which are respectively 20% higher than those of grade II threaded steel bars. C. Seismic resistance: The vanadium-containing steel bar has higher bending resistance, aging performance, higher low-cycle fatigue performance, and its seismic performance is significantly better than Grade II threaded steel. D. Easy welding: Because the carbon content is less than or equal to 0.54%, the welding performance is good, it is suitable for various welding methods, and the process is simple and convenient. E. Convenient construction: The use of new grade III threaded steel bars increases the construction gap and provides a guarantee for construction convenience and construction quality.
4. Hot-rolled H-beam
1. The expression method of hot-rolled H-beam: The three types of H-beam are divided into wide-flange H-beam (HK), narrow-flange H-beam (HZ) and H-beam pile (HU). The expression method is: height H×width B×web thickness t1×wing plate thickness t2. For example, H-beam Q235, SS400 200×200×8×12 is expressed as height 200mm, width 200mm, web thickness 8mm, and wing plate thickness 12mm Wide flange H-shaped steel, its grade is Q235 or SS400. 2. Advantages of hot-rolled H-section steel H-section steel is a new type of economical construction steel. The section shape of H-beam is economical and reasonable, and its mechanical properties are good. The extension of each point on the section is more uniform and the internal stress is small during rolling. Compared with ordinary I-beam, it has the advantages of large section modulus, light weight, and metal saving, which can make building The structure is reduced by 30-40%; because the legs are parallel inside and outside, and the ends of the legs are right-angled, they can be assembled into components, which can save welding and riveting work by up to 25%. It is often used in large buildings (such as factory buildings, high-rise buildings, etc.) that require large cutting capacity and good cross-sectional stability, as well as bridges, ships, lifting and transporting machinery, equipment foundations, supports, foundation piles, etc.
Five, cold-formed steel
Cold-formed steel is a kind of economical cross-section, lightweight and thin-walled steel, also known as steel refrigerated steel or cold-formed steel. It is a section steel with various cross-sectional shapes and sizes made by bending and forming hot-rolled or cold-rolled strip steel. Cold-formed steel has the following characteristics: 1. The section is economical and reasonable, saving materials. The cross-sectional shape of cold-formed steel can be designed according to needs, the structure is reasonable, and the section coefficient per unit weight is higher than that of hot-rolled steel. Under the same load, the weight of components can be reduced and materials can be saved. Cold-formed steel can save 38-50% of metal when used in building structures than hot-rolled steel, and 15-60% when used in agricultural machinery and vehicles. Facilitate construction and reduce overall costs. 2. There are many varieties, and it can produce various profiles with uniform wall thickness and complex cross-sectional shapes and various cold-formed steels of different materials that are difficult to produce by general hot rolling methods. 3. The product has a smooth surface, good appearance, accurate size, and the length can also be flexibly adjusted according to needs, and all are supplied according to fixed length or multiple lengths to improve the utilization rate of materials. 4. It can also be matched with punching and other processes in production to meet different needs. There are many types of cold-formed steel, divided into open, semi-closed and closed cross-sectional shapes. The main products are cold-formed channel steel, angle steel, Z-shaped steel, cold-formed corrugated steel plate, square tube, rectangular tube, electric welded special-shaped steel tube, and rolling door. Wait. Cold-formed steel generally produced has a thickness of 6mm or less and a width of 500mm or less. Products are widely used in mining, construction, agricultural machinery, transportation, bridges, petrochemical, light industry, electronics and other industries.