Q235 Hot rolled steel sheet spot straight hair - national standard building structure steel

Production process

Q235 steel plate is mainly produced by hot rolling process, the specific process is as follows:

1. Raw material preparation: the billet (continuous casting billet or die casting billet) is heated to 1200-1250℃.
2. Roughing and finishing:        

•         Rough rolling stage: the billet is rolled to the middle thickness (30-50mm);
•         Finishing rolling stage: Control the final rolling temperature at 850-900℃ to form the target thickness (1.5-200mm).  

3.Cooling and winding: air-cooled or laminar cooling to room temperature, coil or cut into plates.

4.Surface treatment: pickling (to remove the oxide) or oil to prevent rust.

mechanical properties (GB/T 700 standard)

Implement standard control

Chemical composition (GB/T 700 Q235B)

Typical uses and application scenarios

1. Building structure

• Scene: Steel beams, stair steps, temporary supports
• Advantages: low cost, good weldability, suitable for static load structure

2.Machine building

• Scenario: Machine tool base, conveyor frame, and agricultural equipment shell
• Advantages: Easy machining, suitable for non-precision parts

3.Transportation

• Scenario: Floor of a freight car, corner parts of a container, and non-load-bearing partitions of a ship
• Limitations: Not suitable for high intensity or low temperature environments (need to be upgraded to Q345 or Q355)

4.Daily hardware

• Scenario: Inner lining of security door, shelf beam, common bolts and nuts.
• Advantages: Good cold forming performance, suitable for stamping processing.

Technical parameters and selection suggestions

With its high cost performance, easy processing and wide applicability, Q235 steel has become a universal steel for basic industries around the world. But in the selection should pay attention to:

• Low temperature environment: Q235D (-20℃ impact power standard) should be selected;
• Dynamic load scenario: Q345 (yield strength 345MPa) is recommended.
• Corrosion environment: Use galvanized sheet or weathering steel (such as 09CuPCrNi-A).

Through reasonable matching standards and processes, the economic value of Q235 steel plate can be maximized.