S550QL High Strength Steel Plate
S550QL High Strength Steel Plate
EN10025-6 S550QL is a premium, high-strength, quenched and tempered structural steel plate designed for demanding applications where maximum safety, light weight, and performance under extreme conditions are required.
Standard :
EN10025-6Grade :
S550QL-
Thickness :
3-150 mm -
Width :
800-2500 mm -
Length :
3000-15000 mm
Special thickness, width, and length require negotiation.
We also provide customized processing services.If you have any questions, please contact us.
General Description of S550QL
EN10025-6 S550QL High Strength Steel Plate is a high-quality, high-strength, quenched and tempered structural steel plate primarily used in structural engineering applications that require high steel strength, low-temperature toughness, and workability.
| Grade | S550QL |
|---|---|
| Standard | EN 10025-6: Hot-rolled structural steels - Part 6: Technical delivery conditions for flat products of high yield strength structural steels in the quenched and tempered condition |
| Classification | Hot-rolled Structural Steels |
| Delivery Conditions | Quenched and Tempered(Q&T) |
| Approval By Third Party | ABS, DNV, GL, CCS, LR , RINA, KR, TUV, CE |
| Weldability | Good weldability., but strict process procedures (preheating, suitable welding materials, etc.) must still be followed during welding. |
| Machinability | Cutting can be performed using laser, plasma, or flame cutting, but heat input must be controlled to avoid embrittlement in the heat-affected zone. The bending radius should be ≥3 times the plate thickness, and stress relief treatment is required after cold forming. |
| Surface Quality | Default is "As-Rolled" surface. Special requirements (such as coating pretreatment) must be specified in the order. |
| Inspection Requirements | Non-destructive testing (e.g., UT ultrasonic testing) and re-inspection of mechanical properties can be added as needed. |
Chemical Composition of S550QL
| Grade | S550QL | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Element | C | Si | Mn | P | S | N | B | Cr | Cu | Mo | Nb | Ni | Ti | V | Zr |
| Content (max, %) | 0.200 | 0.800 | 1.700 | 0.025 | 0.015 | 0.015 | 0.005 | 1.500 | 0.500 | 0.700 | 0.060 | 2.000 | 0.050 | 0.120 | 0.150 |
* The chemical composition of EN 10025-6 S550QL High Strength Steel Plate is adjusted within a certain range depending on the thickness.
Carbon Equivalent of S550QL High Strength Steel Plate
| Grade | Thickness (t) [mm] | CEV [max] |
|---|---|---|
| S550QL | t ≤ 30 | 0.47 |
| 30 < t ≤ 40 | 0.48 | |
| 40 < t ≤ 50 | 0.49 | |
| 50 < t ≤ 60 | 0.50 | |
| 60 < t ≤ 100 | 0.51 |
* The carbon equivalent value varies depending on the thickness.For detailed information, please contact us for inquiries.
* Carbon equivalent (CEV) is calculated using the International Institute of Welding (IIW) formula: CEV = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15
Mechanical Properties of S550QL
| Grade | Thickness (t) [mm] | Yield Strength (ReH) [min, MPa] | Tensile Strength (Rm) [MPa] | Elongation (A) [min, %] | Impact Energy (KV) [min] |
|---|---|---|---|---|---|
| S550QL | t ≤ 50 | 550 | 640 - 820 | 16% | 30J (at -40°C, Longitudinal) 27J (at -40°C, Transverse) |
| 50 < t ≤ 100 | 530 | 640 - 820 | 16% | 30J (at -40°C, Longitudinal) 27J (at -40°C, Transverse) | |
| 100 < t ≤ 150 | 490 | 590 - 770 | 16% | 30J (at -40°C, Longitudinal) 27J (at -40°C, Transverse) |
* The mechanical properties of S550QL high-strength structural steel plate vary with thickness.
Applications of S550QL
EN10025-6 S550QL high-strength steel plate is widely used in structural components subjected to heavy loads, impact, or low-temperature environments due to its combined advantages of "high strength, high toughness, and good weldability." Typical applications include:
Heavy machinery: Crane jibs, excavator chassis, and engineering vehicle frames.
Construction and bridges: Load-bearing components of long-span bridges and steel structural supports for high-rise buildings.
Special vehicles: Protective plates or load-bearing structures for mining vehicles and armored vehicles.
Pressure vessels and storage tanks: Large storage tanks designed to withstand high pressure and special pressure vessels (must additionally comply with pressure equipment standards).
Other Information
Temperature Grade Differences
| Grade | Yield Strength (ReH) [min, MPa] | Tensile Strength (Rm) [MPa] | Elongation (A) [min, %] | Impact Energy (KV) [min] |
|---|---|---|---|---|
| S550Q | 550 | 640 - 820 | 16% | 30J (at -20°C) |
| S550QL | 550 | 640 - 820 | 16% | 30J (at -40°C) |
| S550QL1 | 550 | 640 - 820 | 16% | 30J (at -60°C) |
* The differences between S550Q, S550QL, and S550QL1 lie solely in the impact temperature requirements, while other mechanical properties remain consistent.
Equivalent Grade of Other International Standards
| Standard | Grade | Yield Strength (MPa) | Impact Temperature (°C) | Delivery Condition | Equivalence Evaluation |
|---|---|---|---|---|---|
| EN 10025-6 | S550QL | 550 | -40 | Quenched & Tempered | Reference Grade |
| GB/T 16270 (China) | Q550E | 550 | -40 | Quenched & Tempered | Fully equivalent, preferred in Chinese market |
| ASTM (USA) | A514 Grade Q | 620–690 | Negotiation | Quenched & Tempered | High-strength alternative, impact performance requires verification |
| JIS G3106 (Japan) | SM570 | 570 | Room Temp. / -20 | Hot Rolled / Normalized | Similar strength but fails low-temperature performance |
* Grade equivalences are only approximate; actual mechanical properties and chemical composition should be compared.
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