Q355B steel is a low-alloy, high-strength structural steel (with a minimum yield strength of 355 MPa), standardized under the Chinese National Standard GB/T 1591-2018. Widely utilized in the transportation and automotive manufacturing sectors, this steel is frequently employed in the fabrication of vehicle frames, trailers, and heavy machinery; compared to traditional carbon steel, it offers a superior strength-to-weight ratio, excellent weldability, and enhanced load-bearing capacity.
Chemical Composition of Q355B Steel
| Material | C | Si | Mn | P | S | Cr. | Ni | Cu | N |
| Q355B | ≤0.20% | ≤0.55% | ≤1.60% | ≤0.030% | ≤0.030% | ≤0.30% | ≤0.30% | ≤0.40% | ≤0.012% |
Mechanical Properties of Q355B Steel
| Property | Typical Value/Range (Metric) |
|---|---|
| Yield Strength (0.2% offset) | 355 MPa (Min) |
| Tensile Strength | 470 - 630 MPa |
| Elongation | ≥ 20% |
| Impact Strength (Charpy) | ≥ 27 J |
| Impact Test Temp | +20°C |
Why Choose Q355B Steel for Transportation & Automotive Industry?
Lightweighting and High Strength:The yield strength of Q355B is 40% to 50% higher than that of standard steels (such as Q235), thereby permitting the use of thinner structural components. This not only reduces the overall tare weight of transport vehicles but also contributes to lower energy consumption.
Exceptional Weldability and Processing Performance:Q355B exhibits excellent weldability, ensuring that in heavy-duty structural applications, welded joints remain stable, robust, and free of defects.
Enhanced Structural Integrity:Q355B is particularly critical for heavy-duty components-such as vehicle chassis, frames, and load-bearing structures-which demand exceptionally high levels of structural stability and fatigue resistance.
Cost-Effectiveness:Although the unit price per ton of Q355B is higher than that of lower-grade steels, its superior performance allows for a significant reduction in overall material usage. This enables manufacturers to lower their aggregate costs across the stages of material procurement, transportation, and processing.
Applications of Q355B Steel In Transportation & Automotive Industry
Automotive Frames and Structural Components: Q355B is primarily used in the manufacture of chassis frames, main beams, and reinforcing members for heavy-duty trucks, commercial vehicles, and industrial transport vehicles.
Railway and Rail Transit: This steel grade is utilized in the production of components for railway freight cars, high-speed train car bodies, subway trains, and light rail vehicles; specifically, this encompasses structural elements such as car bodies, flooring, side walls, roofs, and luggage racks.
Specialized Vehicles and Equipment: This steel grade is predominantly used to manufacture components and parts for earthmoving machinery, specialized engineering equipment, and crane booms.
New Energy Vehicle (NEV) Infrastructure: Q355B is applied in the fabrication of protective plates for battery trays in new energy buses and commercial vehicles.
Vehicle Car Bodies: Used for constructing the car body structures of specialized commercial trucks.
If you require further details regarding Q355B steel, please do not hesitate to contact us.
As a leading manufacturer of Q355B steel in China, GNEE boasts over 20 years of extensive industry experience. Our warehouses maintain a standing inventory of more than 50,000 tons year-round, ensuring that orders can be shipped in as little as seven days. In terms of quality assurance, we are a dual-certified supplier holding both API and ISO certifications, and we welcome inspections by third-party agencies such as SGS, BV, and Lloyd's.
By choosing our Q355B steel products, you will benefit from our comprehensive, customer-centric support services, as well as our extensive value-added processing capabilities. We would be delighted to provide full-spectrum support and assistance for your project.
Contact now to get Q355B steel
| Type | Q355B |
| Standard | AISI, ASTM, BS, GB, DIN, JIS, etc |
| Certificate | ISO,SGS,CE |
| Length |
Production according to customer requirements |
| Thickness | 8-160MM |
| Width | 2000-2500MM |
| Surface | Coated |
| Technique | Hot rolled |
| Package | Available on request or Standard Export Packing |
| Application | Widely used in Building Construction, Bridge, Architecture, Vehicles Components,hipping,High pressure container, Boiler, Large Structure steel etc. |
What is Q355B steel?
Q355B material is a low-alloy high-strength structural steel, where "Q" means yield strength, 355 means that the yield strength of this steel is 355MPa, and its yield value will decrease as the thickness of the material increases.
What standard is Q355B steel?
Q355B steel is manufactured under the provisions of the GB/T 1591-2018 standard, which governs the mechanical properties, chemical composition, and delivery conditions of high-strength low-alloy structural steels in China.
What is the impact test for Q355B?
Q355B square steel pipe exhibits excellent impact performance. At a room temperature of 20°C, its impact absorbed energy is no less than 34J. This value reflects the material's ability to absorb energy when subjected to impact loads and is a key indicator for evaluating its resistance to brittle fracture.