Q235 and Q355 are two different grades of structural steel used in China, each with distinct properties and applications:
Q235 Steel
- Composition: Q235 steel is a carbon structural steel, characterized by its high strength, good plasticity, and toughness.
- Chemical Composition: Typically contains less than 0.3% carbon, 0.3% to 0.7% manganese, 0.15% to 0.35% silicon, and traces of other elements.
- Properties: It has excellent weldability and machinability, making it widely used in general fabrication, construction, and structural applications where strength is required but not necessarily extremely high.
Q355 Steel
- Composition: Q355 steel is a high-strength low-alloy structural steel, known for its high strength and excellent mechanical properties.
- Chemical Composition: Contains higher levels of carbon, manganese, silicon, and sometimes other alloying elements like nickel, chromium, or copper compared to Q235.
- Properties: Q355 steel offers superior strength and toughness compared to Q235, making it suitable for more demanding structural applications such as bridges, high-rise buildings, and heavy equipment.
Key Differences
- Strength and Toughness: Q355 has significantly higher strength and toughness than Q235 due to its alloying elements and higher carbon content.
- Applications: Q235 is used where moderate strength and good weldability are sufficient, while Q355 is chosen for applications requiring higher strength, durability, and resistance to wear and tear.
- Cost: Q355 is typically more expensive than Q235 due to its enhanced properties and alloy content.
These differences make Q355 suitable for more demanding structural applications where higher strength and performance are required. At the same time, Q235 is used in less critical applications where cost-effectiveness and general structural requirements are sufficient.
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FAQ
Q: What is Q355 steel?
A: Q355 steel is a high-strength structural steel grade that is commonly used in various industries and applications. However, it's important to note that there isn't a specific "grade" of Q355 steel as it is not classified using traditional grade designations like Q235 or Q345.
Q: What is the difference between Q235 and Q355 steel?
A: Applications: Q235 is used where moderate strength and good weldability are sufficient, while Q355 is chosen for applications requiring higher strength, durability, and resistance to wear and tear. Cost: Q355 is typically more expensive than Q235 due to its enhanced properties and alloy content.
Q: What is China steel grade Q355?
A: Q355 is a newer Chinese steel grade that was designed to replace Q345. Its material density is 7.85 g/cm3 and possesses three quality levels, including Q355B, Q355C, and Q355D. It has great mechanical and hot and cold process properties.
| Other steel plate | ||||
| Name | Material | Specification (mm) | Tons | Remark |
| Low Alloy | Q345A, Q345B, Q345C, Q345D, Q345E, Q390, Q420, Q460C, ST52-3, S355J2+N, SS400, SA302GrC, S275NL, 35CrMo | 6 - 350 | 5788.56 | Normalizing, tempered ,controlled rolling, hot rolling , Hot rolling,1st inspection, 2nd inspection, 3rd inspection |
| Pressure Vessel Plate | Q245R, Q345R, Q370R, 16MnDR, 09MnNiDR, 15CrMoR, 14Cr1MoR, 12Cr2Mo1R, SA516Gr60, SA516Gr70, SA516Gr485, SA285, SA387Gr11, SA387Gr12, SA387Gr22, P265,P295,P355GH,Q245R(R-HIC),Q345R(R-HIC) | 3 - 300 | 8650 | Normalizing, tempered ,controlled rolling, hot rolling , Hot rolling,1st inspection, 2nd inspection, 3rd inspection |
| High-Strength Plate | WH785D/E,Q960D/E, Q890D/E,WH60D/E,WH70B,Q550D,Q590D,Q690D/E | 8 - 120 | 3086.352 | Quenched and tempered |
| Wear-Resistant Plate | NM360, NM400, NM450, NM500 | 6 - 150 | 3866.297 | Quenched and tempered |
| Bridge Plate | Q235qC, Q345qC, Q370qC, Q420qC, Q345qDNH, Q370qDNH, A709 - 50F - 2, A709 - 50T - 2 | 8 - 200 | 2853.621 | Hot rolling, normalized ,hot rolling controlled rolling, quenched and tempered + toughness and brittleness |
