S235JR Channel Steel 100x50mm
16Mn Angle Steel 75x75mm
Rectangular Billet 200x240mm Q345B
Our 200mm x 240mm Rectangular Billet represents premium-grade low-alloy high-strength steel manufactured
Large Square Billet 250x250mm Q345B
Large Square Billet 250x250mm Q345B
This 250x250mm Q345B large square billet is engineered to maintain consistent mechanical properties across its thick cross-section, making it suitable for heavy-duty fabrication where structural integrity and dimensional stability are critical. Its controlled chemistry ensures uniform performance during hot working, while its large size minimizes welding joints in large-scale components.
2010 ESTABLISHED
410 EMPLOYEE
363+CLIENTS
13000+ trade
Why Choose Baosteel®
Never stop the technological innovation,more than 50 patents, so that every piece of Products becomes the masterpiece.From consulting to after-sales support, theall-weather, all-process, all-round, whole-hearted service system will Escort for you.
Product details
The Large Square Billet 250x250mm Q345B is a premium low-alloy high-strength steel product designed to meet the rigorous demands of heavy fabrication and large-scale infrastructure projects. Compliant with GB/T 1591-2008 standards, this 250x250mm square billet combines exceptional strength, dimensional stability, and workability, making it an indispensable raw material for creating robust, load-bearing components in construction, machinery, and industrial engineering.
| Parameter | Value | Remarks |
|---|---|---|
| Standard | GB/T 1591-2008 | Low alloy high-strength structural steel standard |
| Grade | Q345B | Impact tested at 20℃ |
| Chemical Composition (wt%) | ||
| – Carbon (C) | ≤0.20 | Ensures good weldability and formability for large-section processing |
| – Silicon (Si) | ≤0.55 | Aids deoxidation and contributes to strength retention |
| – Manganese (Mn) | ≤1.70 | Enhances strength and toughness in thick sections |
| – Phosphorus (P) | ≤0.040 | Minimized to prevent embrittlement in large billets |
| – Sulfur (S) | ≤0.040 | Low content reduces hot cracking during fabrication |
| – Niobium (Nb) | ≤0.07 | Microalloying for grain refinement, critical for large sections |
| – Vanadium (V) | ≤0.15 | Improves strength uniformity across thick cross-sections |
| – Titanium (Ti) | ≤0.20 | Enhances toughness and structural stability in large billets |
| – Nitrogen (N) | ≤0.012 | Controlled to avoid porosity in thick steel |
| Mechanical Properties | ||
| – Yield Strength (ReL) | ≥345 MPa | For thickness ≤16mm; adjusted for 250mm section as per standard |
| – Tensile Strength (Rm) | 470–630 MPa | Ensures load-bearing capacity in heavy structural applications |
| – Elongation (A) | ≥21% | Provides ductility for hot/cold working of large billets |
| – Impact Energy (Akv) | ≥34 J | At 20℃ (longitudinal specimen), resists fracture in thick sections |
| – Bending Test | 180° | Bend diameter: 3a (for 250mm section, ‘a’ = relevant dimension) |
| Dimensions | 250 x 250 mm (square cross-section) | Nominal size; tolerance complies with GB/T 702-2017 |
| Length | 6–12m (customizable) | Standard delivery range; longer lengths available on request |
| Surface Quality | Free from cracks, folds, and excessive scale | Ensures suitability for further processing (forging, rolling) |
| Delivery Condition | Hot rolled, normalized, or TMCP | TMCP recommended for optimal mechanical properties in large sections |
| Typical Applications | Heavy machinery frames, bridge structural components, large-diameter pipe billets, pressure vessel shells, and high-load industrial structures | Ideal for projects requiring large, high-strength raw materials |
Packing and shipping
Factory information
Product certificate
Related products