That senior knows what the specifications of Q235B, Q235C, Q345B, and Q345D are

One by one: 1: Grade B steel with a yield strength of 235 2: Grade C steel with a yield strength of 235 3: Grade B steel with a yield strength of 345 4: Grade D steel with a yield strength of 345 It should be right!

Check the material manual to find out.

1. The difference between the implementation standards:

Q235B grade representation method: The steel grade is composed of three parts: the Chinese pinyin letter representing the yield strength, the yield strength value, and the quality grade symbol. 235B-yield strength value, unit MPa3 B-quality grade is B.

When the demander requires the steel plate to have the performance of the thickness direction, the symbol representing the thickness direction (Z direction performance level) is added after the grade specified above. The grade of steel is composed of four parts: the initial letter Q in Chinese Pinyin representing the word "yield" in yield, the specified minimum yield strength value, the delivery status code, and the quality grade symbol.

The initial letter of the word "yield" of the yield strength of a steel in Chinese pinyin: 355 a specified minimum yield strength value, the unit is megapascals (mpa): the delivery state is normalized or normalized rolling: b quality grade is grade b.

Q355B Executive Standard: GB T1591-2018 "Low Alloy High Strength Structural Steel".

2. The difference in mechanical properties:

Q345B mechanical properties: 16mm - 40m:

63mm - 80mm - 100mm:

150m: >285; 150- 200mm: >275; 200 - 250m:

275;Tensile strength: 450-630MPao Elongation: >21%.

Impact test: 20°.

Q355B mechanical properties: yield strength: 16mm:

355 ;16-40mm: >345; 40-63mum:>335; 63- -80m:

325 ;80-100mm: >315; 100- 150m: >295; 150-200m:

285; 200- 250mm: ≥275;Tensile Strength: 450-630MPao Elongation:

21%。Impact temperature: 20C.

High-quality carbon structural steel:

The two digits at the beginning of the steel number indicate the carbon content of the steel, expressed in a few parts per 10,000 of the average carbon content, for example, the steel number is "45", it is not a sequential number, so it cannot be read as 45 steel.

For high-quality carbon structural steel with high manganese content, the manganese element should be marked, such as 50mn.

Boiling steels, semi-calmed steels and high-quality carbon structural steels for special purposes should be specially marked at the end of the steel number, such as semi-calm steel with an average carbon content of 10b.

High-quality carbon structural steel is based on chemical composition and mechanical properties**. The content of sulfur, phosphorus and non-metallic inclusions in steel is less, indicating that the quality and microstructure are uniform, and they are often used for various important mechanical structure parts that need to be heat-treated.

According to the different chemical compositions, high-quality carbon structural steel is divided into two categories: ordinary manganese steel and higher manganese steel.

Except for the difference in intensity, there is basically not much difference. Both belong to the category of ordinary steel. However, the Q345B performs exactly better than the Q235B in many ways.

Except for the difference in intensity, there is basically not much difference. Both belong to the category of ordinary steel. However, the Q345B performs exactly better than the Q235B in many ways.

Summary. Q235BH steel is different from Q355BH steel.

1. Q235 is carbon structural steel, Q355 is low alloy steel;

2. The chemical composition is different, especially Q355 has high manganese content;

3. The mechanical properties are different, and the tensile strength of Q235 is 375-500MPa; Q355 tensile strength of 470-630MPa;

Q235 ordinary carbon structural steel plate is widely used in construction and engineering structures.

What is the difference between Q235 and Q355B?

Dear, hello, I will give you your question, I am sorting out the answer, it takes some time to type, please wait a while, thank you!

The difference between Q235BH steel and Q355BH steel is 1, Q235 is carbon structural steel, Q355 is low alloy steel; 2. The chemical composition is different, especially Q355 has high manganese content; 3. The mechanical properties are different, and the tensile strength of Q235 is 375-500MPa; Q355 tensile strength of 470-630MPa; Q235 ordinary carbon structural steel plate is widely used in construction and engineering structures.

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The differences between Q235 and Q235B are as follows: 1. Different properties 1. Q235: It is a kind of carbon structural steel.

2. Q235B: carbon structural steel with a quality grade of B. Second, the use of different 1, Q235:

It is widely used in construction and engineering structures. It is used to make steel bars or build factory frames, high-voltage transmission towers, bridges, vehicles, boilers, containers, ships, etc., and is also widely used as mechanical parts that do not require high performance. C and D grade steel can also be used as some professional steel.

It can be used for all kinds of mold handles as well as other unimportant mold parts. 2. Q235B: mainly used for welded structural parts with high quality requirements in buildings and bridge projects.

Extended information: Steel is classified according to carbon content: 1. Low carbon steel:

The carbon content is generally lower than the mass fraction); 2. Medium carbon steel: carbon content is generally mass fraction); 3. High-carbon steel: the carbon content is generally higher than the mass fraction).

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Do you have any other questions?

Summary. Hello dear. Difference between Q235 and Q235B:

The steel is all carbon steel. In the national standard GB T 700-2006, the material distinction between Q235 and Q235B is mainly in the carbon content of steel, the carbon content of steel made of Q235 is not greater, and the carbon content of steel made of Q235B is not greater than; The material of Q235 does not do impact test, while Q235B does room temperature impact test, V-notch. In the case of negotiation with the customer, the carbon content of Q235B can also be shipped according to production.

Hello dear. The difference between Q235 and Q235B: The steel is carbon steel.

In the national standard GB T 700-2006, the material distinction between Q235 and Q235B is mainly in the carbon content of steel, the carbon content of steel made of Q235 is not greater, and the carbon content of steel made of Q235B is not greater than; The material of Q235 does not do impact test, while Q235B does room temperature impact test, V-notch. In the case of negotiation with the customer, the carbon content of Q235B can also be shipped according to production.

Comparatively speaking, the mechanical properties of steel made of Q235B are much better than those of steel made of Q235. In general, steel mills have made identification plates on the finished profiles before they leave the factory. The user can distinguish whether the material is Q235, Q235B, or other materials on the signage.

design pressure p ; The operating temperature is 0 350 °C; =20mm。

Summary. Hello, the differences between Q355B and Q235B are as follows: 1. Different physical properties:

Q355B has better strength, plasticity and hardness than Q235B; 2. Different chemical compositions: the chemical composition of Q355B contains titanium, vanadium, chromium, aluminum, manganese and copper, while Q235B only contains chromium, aluminum and manganese; 3. Different applications: Q355B is suitable for manufacturing bridges, building steel structures, large automobiles and other heavy machinery, etc., while Q235B is more used for constructing pipelines, tracks, etc.; 4. **Different:

Since the Q355B has better performance, it is also higher than the Q235B.

Dear, the differences between Q355B and Q235B are as follows: 1. Different physical properties: Q355B has better strength, plasticity and hardness than Q235B; 2. Different chemical compositions

The chemical composition of Q355B contains titanium, vanadium, chromium, aluminum, manganese, and copper, while Q235B contains only chromium, aluminum, and manganese; 3. Different applications: Q355B is suitable for manufacturing bridges, building steel structures, large automobiles and other heavy machinery, etc., while Q235B is more used for constructing pipelines, tracks, etc.; 4. **Different: Because Q355B has better performance, it is also higher than Q235B.

Dear, is there anything else I can serve you, if you have, you can contact me.

Summary. The differences between Q355B and Q235B are as follows: 1. The mechanical ability of Q235B is much greater than that of Q355B.

There is also a big difference in the mechanical ability of the two, if you want to improve the mechanical ability of the high-mast lamp, then you can choose the Q235 material.

The differences between Q355B and Q235B are as follows: 1. The mechanical ability of Q235B is much greater than that of Q355B. There is also a big difference in the mechanical ability of the two, if you want to improve the mechanical ability of the high-mast lamp, then you can choose the Q235 material.

2. The material distinction between Q355B and Q235B is mainly in the carbon content of steel. The carbon content of the steel made of Q235B is between, and the carbon content of the steel of Q355B is between; In terms of tensile and impact tests, the steel made of Q235B does not do the impact test, and the steel made of Q235B does the impact test at room temperature, with a V-shaped notch.

3. Q235B square tube metal structural parts, carburizing or cyanide parts with low core strength requirements. Tie rods, connecting rods, hooks, couplers, bolts and nuts, sleeves, shafts and weldments. Q355B square tube has good comprehensive mechanical properties, low temperature performance, good plasticity and weldability, and is used as a structure, mechanical parts, building structure, general metal structural parts that bear dynamic loads such as medium and low pressure containers, oil tanks, vehicles, cranes, mining machinery, power stations, bridges, etc., and can be used in a hot rolled or normalized state, and can be used for various structures in cold areas below -40 °C.

What is the difference between the two?

Dear,**Q355B is more expensive than Q235B.

1. The definitions are different.

Q235: Q235 ordinary carbon structural steel is also known as A3 steel.

Ordinary carbon structural steel plate is a kind of steel material.

Q represents the yield limit of this material, and the subsequent 235 refers to the yield value of this material, which is about 235MPa. And with the increase of the thickness of the material and its yield value decreases, due to the moderate carbon content, good comprehensive performance, strength, plasticity and welding and other properties are better matched, the most widely used.

Q345: Q345 is a type of steel. It is a kind of low-alloy steel.

2. The application is different.

Q235: Widely used in architectural and engineering structures. It is used to make steel bars or build factory frames, high-voltage transmission towers, bridges, vehicles, boilers, containers, ships, etc., and is also widely used as mechanical parts with low performance requirements.

C and D grade steel can also be used as some professional steel.

It can be used for all kinds of mold handles as well as other unimportant mold parts. Q235 steel is used.

As a punch material, it is used directly without tempering after quenching, and the hardness is 36 40HRC, which solves the phenomenon of punch fragmentation in use.

Q345: Widely used in bridges, vehicles, ships, buildings, pressure vessels, special equipment.

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3. The performance is different.

Q235: Due to the moderate carbon content, the comprehensive performance is better, and the strength, plasticity and welding properties are well matched, and the most widely used.

Q345: Q345 decreases the yield value of the material as its thickness increases. And the domestic one may be less than 345, so in the mechanical design.

The strength must be less than 345, otherwise there will be problems.

When the crystallization product is cooled to 800, a fine cracking network appears. As the cooling continues to 200-275, the structural change of cristobalite from high temperature to low temperature (i.e., -cristobalite a-cristobalite ) occurs, accompanied by volumetric fusion, and if the crystallization layer is deep, the quartz glass also breaks. Since crystallization often occurs in places with impurities, the surface state and the surrounding refractory materials and atmosphere before high-temperature use are very important.

Q235B is mild steel, and Q355B is medium carbon steel. Q235B and Q355B are ferrite metallographic structure, mainly containing carbon, silicon, manganese, etc., is a grade named after yield strength, are easy to iron precipitation rust, all ensure mechanical properties, do room temperature 20 degree impact test, the difference between the two grades is, Q235B carbon content is lower than Q355B, hardness, strength is also lower than Q355B, the market **Q235B is low, Q355B is high.