Global Steel Supply & Processing
Specify Q550D quenched-and-tempered high-strength plate to GB/T 16270-2009. Review thickness-dependent strength, −20°C longitudinal Charpy energy, carbon equivalent, heat traceability and export supply terms in one RFQ.
This page specifies the GB/T 16270-2009 quenched-and-tempered Q550D steel-plate route. Check the material standard and mill test certificate before comparing another similarly named product.
| Purchase field | What to specify / verify |
|---|---|
| Product identity | Q550D high-strength structural steel plate; D quality level; quenched and tempered condition. |
| Governing steel-plate standard | GB/T 16270-2009, not a hot-rolled sheet or section specification. Confirm the standard and grade on the purchase order and MTC. |
| Mechanical-property coverage | Plate thickness up to 150 mm is covered in three mechanical-property bands by the standard. Actual stock and source-mill rolling / Q&T size capability must be confirmed. |
| Delivery condition | Quenched and tempered (Q&T), with finished mechanical and Charpy properties verified for the specified plate thickness. |
| Yield strength | 550 MPa through 50 mm; 530 MPa above 50–100 mm; 490 MPa above 100–150 mm. |
| Tensile strength | 640–820 MPa through 100 mm; 590–770 MPa above 100–150 mm. |
| Charpy toughness | −20°C; 47 J minimum average longitudinal Charpy V-notch energy for full-size samples. Reduced-size specimen provisions apply to thinner steel plate. |
| Carbon equivalent | Maximum CEV 0.65% through 50 mm; 0.77% above 50–100 mm; 0.83% above 100–150 mm. |
| Dimensional requirement | Specify thickness × width × length, tolerances under GB/T 709, flatness, plate marking and quantity. |
| Supporting documents | MTC including producer, standard, heat analysis, CEV, mechanical results, −20°C impact records, Q&T state and any agreed additional inspection. |
The Q550D designation refers to 550 MPa minimum yield only in the first standard thickness band. Higher plate thicknesses have different specified minimum yield and tensile ranges.
| Plate thickness | Min. yield (MPa) | Tensile (MPa) | Min. elongation |
|---|---|---|---|
| ≤50 mm | 550 | 640–820 | 16% |
| >50–100 mm | 530 | 640–820 | 16% |
| >100–150 mm | 490 | 590–770 | 16% |
Values are for Q550D quenched-and-tempered plate to GB/T 16270-2009, Table 2. Tensile test specimens are transverse; Charpy specimens are longitudinal. Confirm test positions, dimensions, heat numbers and measured results in the actual mill certificate.
Send the full plate schedule and working thickness range. We will check the producer’s Q&T route, mill certificate and available shipment lots.
Table 1 limits are maxima for heat analysis. Cu, Cr, Ni, Mo, B, V, Nb and Ti entries are permitted ceilings, not a guarantee that every heat contains these alloy additions.
| Element | Max. content (%) |
|---|---|
| C | 0.20 |
| Si | 0.80 |
| Mn | 1.70 |
| P | 0.025 |
| S | 0.015 |
| Cr | 1.50 |
| Ni | 2.00 |
| Element | Max. content (%) |
|---|---|
| Cu | 0.50 |
| Mo | 0.70 |
| V | 0.12 |
| Nb | 0.06 |
| Ti | 0.05 |
| B | 0.0050 |
| Nominal thickness | Maximum CEV | Procurement use |
|---|---|---|
| ≤50 mm | 0.65% | Include heat-specific CEV in the WPS review. |
| >50–100 mm | 0.77% | Review preheat and hydrogen control for the actual section. |
| >100–150 mm | 0.83% | Validate heavier-section weld procedure and toughness. |
Standard CEV calculation: C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15. At least one permitted grain-refining element is specified by the standard. Ask for actual element values and calculated heat CEV on the mill certificate; agree CET reporting in the purchase contract if needed.
For GB/T 16270-2009 Q550D the specified longitudinal average impact energy is 47 J at −20°C with the applicable specimen-size, sampling and retest rules.
D quality level is tested at −20°C for the baseline Charpy requirement.
Minimum average longitudinal absorbed energy for full-size V-notch specimens.
For thickness below 12 mm, check reduced-size specimen and adjusted acceptance rules; plates below 6 mm do not undergo this Charpy test under the stated standard.
Specify −20°C and 47 J where applicable, plus sample orientation, plate thickness, extra low-temperature tests and witnessing requirements.
Under GB/T 16270-2009, quenched and tempered condition defines the material delivery route. Obtain the precise source-mill details and measured impact performance for the selected thickness.
GB/T 16270-2009 covers quenched-and-tempered structural steel plate. The actual mill controls austenitization, cooling and tempering to meet mechanical and toughness requirements within its approved production route.
Use Q550D Q&T steel plate in welded structural components only where the design, load case, impact-temperature class and qualified fabrication route call for this steel.
Box sections, welded booms and highly loaded support plates where the design calls for verified high-strength material.
Load-carrying machinery structures and fabricated supports. Abrasion-facing liners require a separate wear-grade assessment.
Fabricated high-strength beams, box structures and reinforcing sections engineered for the specified service.
Structural members for heavy vehicles and machinery when matching thickness, fatigue and weld procedures are approved.
Welded equipment supports and machinery bases with defined proof-strength and traceability needs.
Project-specific structural plate uses only where the relevant design and acceptance rules explicitly permit this material.
Engineering suitability must be validated from the project load cases, fatigue and buckling criteria, welding qualification and applicable structural code. This plate is not marketed as an interchangeable wear-resistant steel or as pressure-vessel steel.
For Q550D, the source heat-treatment route, certificate and cutting dimensions have to match the contract just as closely as price and lead time.
Keep GB/T 16270, Q550D, Q&T, thickness band and −20°C impact requirements visible in the quote.
We confirm the specific producing mill, heat-treated plate dimensions and quantities before supply commitment.
Coordinate a matching MTC with chemistry, carbon equivalent, tensile, impact and delivery condition.
Align packaging, plate identification, Incoterm, cut list and dispatch records with the order.
BAOSTEEL METAL company-wide profile: annual output 8 million MT, regular inventory 1 million MT, 500,000 m² operating area and 1,000+ employees. These figures describe the whole business, not Q550D-specific production, stock or source-mill approval.
Q550D quenched-and-tempered plate supply depends on rolling dimensions, Q&T facilities, tested thickness and actual inventory. We check these against the required order quantity.
Before release, match the supply heat with the ordered grade, plate thickness, Q&T process, −20°C impact records and any project-specific acceptance documents.
| Purchase field | What to specify / verify |
|---|---|
| Material identity | Q550D Q&T plate, GB/T 16270-2009, source steelworks and production heat. |
| Heat number | Matching heat / plate identification and ordered dimensions. |
| Chemistry | Heat analysis, P/S limits, fine-grain additions and CEV checked against the ordered thickness band. |
| Tensile tests | Transverse test results, thickness band, yield, tensile and minimum 16% elongation. |
| Impact tests | Longitudinal Charpy results at −20°C, specimen dimensions, individual energy values and frequency. |
| Heat treatment | Quenching and tempering status; obtain treatment reports if specified in the contract. |
| Optional checks | UT acceptance, Z-direction quality, dimensional inspection and third-party witnessing only when agreed. |
Specify the test method, acceptance level, sampling frequency, certificate format and any nominated inspection agency.
High strength Q&T plate requires a qualified welding route suited to thickness, restraint, hydrogen level and heat-affected-zone toughness. The actual heat chemistry is more useful than a single generic preheat number.
Include nominal and cut dimensions, finished thickness, flatness, surface quality and plate marking on the Q550D schedule. The source mill confirms available sizes in the requested Q&T condition.
Choose the actual finished thickness band, tolerance class and flatness criterion. Dimensional tolerances can reference the ordered GB/T 709 edition where applicable.
Specify mill or cut edges, identification marks, surface acceptance, corrosion protection and shipping supports appropriate to heavy plates.
Calculate theoretical Q550D plate mass from the requested sizes and number of pieces using a planning density of 7,850 kg/m³.
Formula: thickness × width × length × 7.85 × 10⁻⁶ = kg per plate (dimensions in mm). Multiply by quantity; divide kg by 1,000 for metric tonnes.
Include piece quantities, finished sizes, drawing revisions, tolerances, required edge quality and heat-number transfers.
Processing is offered subject to thickness, steel condition, drawing and workshop capacity; the resulting parts retain the original material heat identity.
Review kerf, thermal effects and dimensional allowance for Q&T high-strength plate.
Where plate thickness and equipment permit, evaluate CNC laser or alternative cutting technology.
Agree bevels, holes, marking and any extra inspection needed after processing.
Thermal cutting and subsequent forming can change local properties. The purchaser’s fabricator should approve the procedure for the relevant part design, plate thickness and Q&T condition.
Order execution includes steel plate identification, matching documents, stable handling and agreed transport terms. Packaging is selected around the actual plate dimensions and route.
Browse adjacent structural strength grades and material systems. Each comparison requires the design authority to review standard, delivery condition, impact temperature, thickness and welding route.
460 MPa grade family under GB/T 16270 Q&T plate; lower minimum yield class with C-level impact.
Higher 690 MPa grade family; verify its own thickness-specific tensile limits and D-level Charpy.
EN 10025-6 Q&T steel with a distinct technical delivery standard and low-temperature toughness level.
ASTM Q&T structural steel; its chemistry, thickness limits and testing are separate from GB/T 16270.
Same nominal strength family, different specified impact temperatures and minimum impact-energy levels.
Lower-strength ASTM HSLA steel; different product route and engineering acceptance.
Related grades are given for procurement comparison. Add internal hyperlinks only to live WordPress pages; a replacement grade requires project engineering approval.
Reference the exact grade, D-level impact and Q&T heat treatment. Add inspection acceptance levels and delivery terms before confirming the purchase.
Q550D is a high-strength structural steel plate grade specified here in quenched and tempered condition to GB/T 16270-2009. The D quality level defines the −20°C baseline impact test.
The specified route is GB/T 16270-2009 for Q&T steel plate. Confirm the material standard, grade, condition and test scope on the purchase order and MTC.
No. The GB/T 16270 table specifies 550 MPa through 50 mm, 530 MPa above 50–100 mm and 490 MPa above 100–150 mm.
The tensile-strength range is 640–820 MPa to 100 mm thickness and 590–770 MPa above 100 mm up to 150 mm.
The D quality grade specifies a longitudinal Charpy V-notch test at −20°C with minimum average energy of 47 J for full-size specimens; thinner specimens follow the standard size rules.
Yes, when ordered to the GB/T 16270-2009 Q&T plate route. Require the relevant delivery condition and heat identity on the mill certificate.
The CEV limit is 0.65% through 50 mm, 0.77% above 50–100 mm and 0.83% above 100–150 mm. Actual weldability also depends on individual heat chemistry, joint design and welding procedure.
Grade labels or approximate cross-reference tables do not establish automatic equivalence. Check the exact standard, grade suffix, thickness range, delivery state and design approval.
Cutting, edge preparation and heat-number transfers can be reviewed against the drawing, plate thickness and workshop capacity.
Provide the grade and GB/T 16270 edition, thickness, width, length, quantity, Q&T and impact requirements, CEV or CET reporting, MTC and supplementary inspection, destination and delivery term.
Send your GB/T 16270-2009 Q550D requirement, thickness × width × length, tonnes, −20°C Charpy, CEV limits, Q&T certificate, optional cutting and destination. We confirm the source mill and actual supply scope for quotation.
Send your required grade, dimensions, quantity and destination. Our team will review the inquiry.
