Q690D steel plate is a high-strength low-alloy (HSLA) structural steel plate with a minimum yield strength of 690 MPa, specifically designed for heavy-duty and load-bearing applications. Possessing excellent toughness, weldability, and low-temperature performance, it is an ideal material choice for heavy engineering machinery, crane booms, and bridge construction.
Chemical Composition of Q690D Steel Plate
The chemical composition of Q690D steel plate typically complies with the GB/T 16270 or GB/T 1591 standards, incorporating specific maximum limits to ensure high strength and low-temperature toughness.
| Element | Q690D Max Content (wt%) |
|---|---|
| Carbon (C) | ≤ 0.18 |
| Silicon (Si) | ≤ 0.60 |
| Manganese (Mn) | ≤ 2.0 |
| Phosphorus (P) | ≤ 0.030 |
| Sulfur (S) | ≤ 0.025 |
| Nickel (Ni) | ≤ 0.80 |
| Chromium (Cr) | ≤ 1.00 |
| Molybdenum (Mo) | ≤ 0.30 |
| Niobium (Nb) | ≤ 0.11 |
| Vanadium (V) | ≤ 0.12 |
| Titanium (Ti) | ≤ 0.020 |
| Boron (B) | ≤ 0.004 |
| Aluminum (Al) | ≥ 0.015 |
Mechanical Properties of Q690D Steel Plate
For Q690D material, a critical aspect that engineers must consider is the dependence of its mechanical properties on thickness.
As the plate thickness increases, the achievable yield strength and tensile strength naturally decrease-a phenomenon rooted in the physical principles governing cooling characteristics across the thickness dimension during the heat treatment process. The table below summarizes the mechanical property requirements for various thicknesses.
| Plate Thickness (mm) | Yield Strength, min (MPa) | Tensile Strength (MPa) | Elongation, min (%) | Impact Energy AKV at -20°C, min (J) | Cold Bend 180° |
|---|---|---|---|---|---|
| ≤ 16 | ≥ 690 | 770–940 | ≥ 14 | ≥ 47 | d = 3a |
| 16–40 | ≥ 670 | 770–940 | ≥ 14 | ≥ 47 | d = 3a |
| 40–63 | ≥ 660 | 770–940 | ≥ 14 | ≥ 47 | d = 3a |
| 63–80 | ≥ 640 | 730–940 | ≥ 14 | ≥ 47 | d = 3a |
Key Advantages of Q690D Steel Plate
Exceptional High-Strength Characteristics:Boasting a yield strength of 690 MPa and a tensile strength ranging from 730 to 940 MPa, Q690D demonstrates superior load-bearing capacity compared to conventional steels, thereby enabling the fabrication of structural components that are thinner, lighter, and more robust.
Excellent Low-Temperature Toughness:The "D" designation signifies that this steel retains guaranteed impact resistance with an impact energy range of 31J to 47J,even in cryogenic environments as low as -20°C, making it an ideal choice for operations in harsh, cold climates.
Outstanding Weldability and Processability: Despite its exceptionally high strength, Q690D maintains excellent weldability; furthermore, it can be processed through techniques such as controlled rolling, normalizing, or tempering to meet a wide variety of specific application requirements.
Weight Reduction Advantages:Given that the strength of Q690D far exceeds that of traditional steels, engineers can utilize significantly less material when designing structures to achieve equivalent or even superior load-bearing capabilities, thereby substantially reducing the overall dead weight of the equipment.
Key Applications of Q690D Steel Plate
Construction Machinery: Widely utilized in structural components subjected to high loads and severe impact forces,such as excavator booms, crane jibs, concrete pump outriggers, and scrapers.
Mining Machinery: Primarily employed in hydraulic roof supports for coal mines, electric shovel components, and drilling equipment; in these sectors, structural integrity and strength are of paramount importance.
Heavy Transport Equipment: Used for the chassis of heavy-duty transport vehicles, heavy-duty flatbed trailers, and high-strength components for logistics trucks.
Structural Engineering and Bridge Construction: Applied in the trusses of long-span bridges, load-bearing members in high-rise buildings, and flanges for wind turbine towers.
Marine and Offshore Structures: Utilized in port machinery such as cranes,as well as other marine equipment where exceptional strength and low-temperature toughness are strictly required.
If you require further details regarding our Q690D steel plate, please do not hesitate to contact us.
As a leading manufacturer of Q690D steel plate in China, GNEE boasts over 20 years of extensive industry experience. Our warehouses maintain a standing inventory of over 50,000 tons year-round, ensuring that orders can be dispatched 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 Q690D steel plate 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-scale support and assistance for your project.
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| Specification | Width: 600-3000mm Thickness:2mm-100mm or as customers' special requirements; |
| Length | Length 1000-12000mm or as customers' special requirements |
| Grade | Q690D |
| Standards | GB/T24186-2009, Q/OHAC 839-2021, GB/T709-2006, ASTM A36, JIS G4051,DIN EN10083, SAE 1045, ASTM A29M |
| Surface | Smooth, straight, bright, no blur on both ends |
| Packaging | Standard exporting packing or as client's requirement |
| Certificate | ISO9001:2008 |
| Processing technique |
1.Heat treatment facilities for hot-rolled, controlled rolling,normalizing. 2.Annealing, tempering, quenching, normalizing plus tempering, quenching and tempering. 3. Other delivery states are available as customers' requirement. |
| Feature of hot rolled steel plate |
1.Heat conduction. 2.Excellent freezing, even structure with pressure resistance. 3.Good mechanical properties |
| Excellent performances |
1.High strength, good toughness. 2.Easy for molding process and good weld ability. |
| Main application |
1.Automobile, Bridges, Buildings. 2.Machinery, Pressure vessel industries. 3.Ship building, Engineering construction. 4.Mechanical manufacturing, Pavement slab, ect. |
What is Q690D steel equivalent to?
Q690D steel is a Chinese GB/T 16270 standard high-strength, quenched and tempered structural steel, with its closest equivalent being the European standard EN 10025-6 S690Q. It is designed for low-temperature applications (impact tested at -20°C) and is commonly used in heavy construction machinery and large-scale structural engineering
What are the properties of Q690D steel?
The mechanical properties of Q690D steel plate are: yield strength ≥ 690 MPa, tensile strength 730-940 MPa, elongation after fracture ≥ 14%, impact energy 31J. Application of Q690D steel plate: Q690D steel plate has high strength, good plasticity and toughness, good weldability, good cold and hot properties.
What is the hardness of Q690D?
The averaged Rockwell hardness of the Q690D specimen is 25.3 HRC.
What is the delivery state of Q690D?
Q690D is usually delivered in a Quenched and Tempered (Q+T) state to ensure its high strength and excellent toughness.