Exposed structural steel refers to the structural form that keeps the details of steel structure and its joints visible under the premise of meeting the quality requirements of steel structure in the building.

What are the requirements of the AESS standard for the processing of steel profiles?

1. No steel mill rolling trademarks, steel marks or raised marks are allowed;

2. It is forbidden to lift steel and components with bite printing;

3. During assembly, it is forbidden to weld temporary support on the exposed surface of components, and it is forbidden to hammer;

4. Minimum weld exposure;

5. the butt weld width is consistent, straight, and polished to flush with the base material, weld residual height is zero;

6. grinding along the weld length direction, the vertical direction of grinding is easy to lower than the base metal surface;

7. After shot blasting or sandblasting, the visible defects shall be welded and filled or polished to remove the defects.

The chemical composition and mechanical properties of 12Cr1MoV alloy structural steel are excellent, the tensile strength and yield point are above the standard, but also has high plasticity and oxidation resistance. It is widely used in high pressure, ultra high pressure, subcritical superheater, collecting box and main steam conduit. Not only that, the process and weldability of this steel is also excellent.

The two digits at the beginning of the steel number represent the carbon content of the steel, which is expressed by a few millionths of the average carbon content. For example, 40Cr and 25Cr2MoVA alloy tubes, the main alloy elements in the steel are generally expressed by a few percent, except for some microalloy elements. When average alloy content < 1.5%, generally only the element symbol is marked in the steel number, but not the content, but in special circumstances easy to confuse, the element symbol can be marked with the number "1"; The alloy elements in steel, such as vanadium V, titanium Ti, aluminum AL, boron B and rare earth RE, all belong to microalloying elements. Although the content is very low, they should still be marked on the steel number. For example, in 20MnVB steel. Vanadium is 0.07-0.12% and boron is 0.001-0.005%. High quality steel should be added "A" at the end of the steel number to distinguish it from ordinary high quality steel. Special purpose alloy structural steel with a prefix (or suffix) denoting the purpose of the steel. For example, the 30CrMnSi steel specially used for riveting screws is expressed as ML30CrMnSi.

1. Steel used as parts of various machines. It includes carburizing steel, tempering steel, spring steel and rolling bearing steel.

2. Steel used for engineering structures. It includes carbon steel A, B, special steel and ordinary low alloy steel.

What is the material of steel S400

S400 is JIS standard of Japanese steel, equivalent to the domestic Q235A structural steel, can be used for casting, used in casting steel. S400 is a Japanese brand, and the common structural steel in JIS series is mainly composed of three parts: the first part is the material, such as: S for steel, F for iron; The second part represents different shapes, types and uses, such as P for plate, T for tube, K for tool; The third part shows the characteristic number, which is generally the minimum tensile strength. For example: SS400 - the first S represents steel, the second S represents "structure", 400 is the lower limit tensile strength of 400MPa, the overall tensile strength of 400 mpa ordinary structural steel.

Q195, Q215, Q235, Q345

Q235 represents: carbon structural steel - general plate is a kind of steel material. Q is the yield of this material, and 235 is the yield of this material, which is around 235. The yield value will decrease with the increase of material thickness.

Q235A, Q235B, Q235C, Q235D. This is the grade of distinction, represents, mainly the impact of the temperature is different!

A, B, C, D, the difference is the impact temperature in their performance. They are: Q235A, no impact; Grade Q235B, is 20 degrees room temperature shock;

Grade Q235C, 0 degree impact; Grade Q235D, it's a -20 impact. At different impact temperatures, the impact values are also different.

Element content: Sulfur content of A, B, C and D decreased successively; A and B have the same phosphorus content, followed by C, and D has less phosphorus content.

What is H-shaped steel

H section steel is a new type of economical building steel. It is an economic cross-section steel with good mechanical properties, which is optimized and developed for I-beam steel. It is named because its section is the same as the English letter "H".

The main features are as follows:

1. high structural strength: compared with I-steel section modulus is large, under the same bearing conditions can save metal 10-15%.

2. Flexible and rich design style: in the case of the same beam height, the steel structure can be 50% larger than the concrete structure, so that the building layout is more flexible.

3. high structural stability: the steel structure is dominated by hot rolled H-beam steel, scientific and reasonable structure, good plasticity and flexibility, high structural stability. Especially suitable for some earthquake prone areas of the building structure.

4. increase the effective use area: compared with concrete structure, steel structure column cross-sectional area is small, can increase the effective use area of the building. Depending on the building form, the effective use area can be increased by 4-6%.

5. easy processing: easy structural connection and installation, but also easy to disassemble and reuse.

6. High degree of industrial production: The steel structure based on hot rolled H beam has a high degree of industrial production, which is convenient for mechanical manufacturing, intensive production, high precision, convenient installation and easy quality assurance. You can build real house manufacturing plants, bridge manufacturing plants, industrial plants, manufacturing plants, etc.

7. the construction speed is fast: covers an area of small, suitable for all-weather construction, the influence of climate conditions is small. The construction speed of hot rolled H-beam steel structure is about 2-3 times that of concrete structure, and the capital turnover rate is doubled, which reduces the financial cost and saves investment.