What is the S690Q standard?
The S690Q standard refers to a high-yield strength, fine-grain structural steel that meets the European standard EN 10025-6, meaning it's delivered in a quenched and tempered (Q) condition, offering a minimum yield strength of 690 MPa for demanding applications like heavy machinery, cranes, and offshore structures. This steel provides excellent toughness, weldability, and strength, making it ideal for load-bearing components.
S690Q has become the industry standard for the manufacturing of heavy-duty lifting and earthmoving equipment. In the world of mobile cranes, the material's high yield strength is critical for creating telescopic booms that can extend to great heights while supporting massive loads. Similarly, in the mining sector, S690Q is used to fabricate the frames and bodies of dump trucks, excavators, and loaders. These machines operate in high-stress environments where abrasion and mechanical fatigue are constant threats. The high tensile strength of S690Q ensures that these components can withstand the rigors of daily operation, significantly extending the maintenance intervals and reducing the risk of catastrophic structural failure.
The energy and infrastructure sectors rely heavily on S690Q for critical load-bearing components. In offshore oil and gas platforms and wind turbine foundations, S690Q provides the necessary rigidity to resist the relentless forces of wind and waves. Its ability to support immense weight with minimal material makes it ideal for the construction of high-load bridges, trestles, and skyscrapers. In these applications, S690Q allows architects to design sleeker, more aesthetically pleasing structures that would be impossible with lower-grade steels. Furthermore, its resistance to fatigue makes it suitable for bridges that must endure millions of load cycles from heavy traffic over several decades.
S690Q's unique properties also extend to the specialized transport industry and the manufacturing of pressure vessels. It is frequently used in the construction of trailers and tankers that carry heavy or hazardous materials. By reducing the weight of the vehicle itself, S690Q allows for a higher volume of cargo to be transported per trip, optimizing logistics and reducing environmental impact. In the realm of pressure vessels, while S690Q is not a dedicated boiler steel, its high strength allows for the design of thinner-walled tanks that can still safely contain high internal pressures. This versatility across diverse sectors proves that S690Q is one of the most adaptable high-strength steels available on the market today.
S690Q is a European standard (EN 10025-6) high-strength structural steel, noted for its excellent yield strength of at least 690 MPa, achieved through quenching and tempering (the 'Q'), making it ideal for extreme load applications like heavy machinery, cranes, bridges, and offshore structures where high strength-to-weight is critical.
Key Characteristics
S: Denotes Structural Steel.
690: Minimum yield strength in Megapascals (MPa) for thicknesses up to 50mm.
Q: Indicates the steel is delivered in the Quenched and Tempered condition, providing high toughness.
Properties: Offers a high tensile strength (770-940 MPa), good ductility (elongation≥14% ), and impact toughness at low temperatures (e.g., 30J at -20°C for S690Q).
Applications
-Heavy lifting equipment (cranes).
-Mining and construction machinery.
-Bridges and support structures.
-Offshore applications (wind turbines, drilling rigs).
Variants
S690QL: Same as S690Q but with improved low-temperature impact properties, tested at -40°C.
S690QL1: Even tougher, with impact testing at -60°C.
In essence, S690Q provides superior strength for demanding structural applications, allowing for lighter yet stronger designs.
Is S690Q carbon steel?
Yes, S690Q is a type of high-strength low-alloy (HSLA) steel, often described as a high-strength carbon steel or low-alloy steel, known for its exceptional yield strength (690 MPa) achieved through quenching and tempering, making it ideal for heavy engineering where strength-to-weight ratio is critical, like in bridges, cranes, and mining equipment.
What are the typical application fields of S690Q ?
S690Q is a high-strength structural steel used in heavy-duty applications requiring excellent strength-to-weight ratios, such as cranes, bridges, offshore platforms, heavy machinery, wind turbine supports, and high-rise buildings, allowing for lighter, more efficient, and durable designs in construction, mining, and transportation. Its key benefit is enabling lighter structures that can handle extreme loads and dynamic stresses, reducing material use and improving fuel efficiency in transport.
What temperature is S690Q ?
S690Q is a high-strength, quenched and tempered (Q+T) structural steel, and its "temperature" typically refers to two critical values: it is tested for impact toughness at a minimum of -20°C (where it must maintain an energy absorption of at least 30J), and its mechanical properties are generally guaranteed for service up to approximately 580°C, beyond which it may lose significant yield strength
Equivalent grades of steel S690Q (1.8931)
| EU EN |
USA - |
Germany DIN,WNr |
France AFNOR |
Sweden SS |
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| S690Q |
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Chemical composition % of steel S690Q (1.8931): EN 10025-6-2004
| C | Si | Mn | Ni | P | S | Cr | Mo | V | N | Nb | Ti | Cu | Zr | B | CEV |
| max 0.2 | max 0.8 | max 1.7 | max 2 | max 0.025 | max 0.015 | max 1.5 | max 0.7 | max 0.12 | max 0.015 | max 0.06 | max 0.05 | max 0.5 | max 0.15 | max 0.005 | max 0.83 |
Mechanical properties of steel S690Q (1.8931)
| Nominal thickness (mm): | 3 - 50 | 50 - 100 | 100 - 150 |
| Rm - Tensile strength (MPa) | 770-940 | 760-930 | 710-900 |
| Nominal thickness (mm): | 3 - 50 | 50 - 100 | 100 - 150 |
| ReH - Minimum yield strength (MPa) | 690 | 650 | 630 |
| KV - Impact energy (J) longitud., | 0° 40 |
-20° 30 |
| A - Min. elongation Lo = 5,65 √ So (%) | 14 |
1 What precautions should be taken when welding S690Q ?
When welding S690Q high-strength steel, key precautions include using low-hydrogen consumables, controlling heat input to prevent HAZ softening and cracking, implementing appropriate preheating (especially for thicker plates) based on thickness and carbon equivalent, ensuring thorough joint cleaning, and managing post-weld cooling to avoid hydrogen-induced cracking and maintain mechanical properties, alongside standard PPE and ventilation.
2 What is S690Q Steel material?
S690Q steel is a high-yield-strength, quenched, and tempered structural steel (EN 10025-6 standard) known for exceptional strength, toughness, and durability, used in heavy machinery, construction (cranes, bridges), and lifting equipment where high strength-to-weight ratio is crucial, offering superior performance and efficiency in demanding applications.
3 What is the technical Condition of S690Q Plates?
S690Q plates are high-yield strength structural steel (EN 10025-6) delivered in a quenched and tempered (Q+T) condition, offering excellent strength (min 690 MPa yield), toughness, and formability for heavy loads, with good low-temperature impact properties (tested at -20°C), but requiring controlled welding procedures due to its high strength.
4 What are common testing requirements for S690Q ?
Common testing for S690Q steel, governed by EN 10025-6, includes tensile testing (yield & tensile strength, elongation) and Charpy V-notch impact testing (typically at -20°C for 30 Joules minimum). Other essential tests are heat analysis, with optional ultrasonic testing (UT) and product analysis, all requiring a mill test certificate (EN 10204 3.1/3.2).
5 What is S690Q Plate Thickness?
S690Q is a high-strength structural steel with a minimum yield strength of 690 MPa, typically supplied quenched and tempered, and its plate thickness varies, commonly ranging from around 3-6mm up to 300mm, with specific dimensions depending on the manufacturer and application, but often seen in ranges like 8-100mm for general Q/QL grades and up to 50mm for QL1.
6 What is S960Q equivalent to?
S690Q is a European high-strength structural steel (EN 10025-6) with a 690 MPa yield strength, and its equivalents include ASTM A709 Grade 100, German TStE690V/DILLIMAX 690, Swedish WELDOX 700, French E690T, and ISO E690, all representing similar quenched and tempered (Q&T) steels for heavy-duty applications, though specific properties like low-temp impact testing (e.g., S690QL tested at -40°C) can vary slightly between standards.
7 What is the hardness of S690Q ?
The hardness of S690Q steel varies slightly with thickness but generally falls within the range of 210 to 278 Brinell Hardness (HB), with thicker plates having slightly lower minimum hardness values (e.g., 228-278 HB for ≤50mm, 210-266 HB for >100mm) due to the quenching and tempering process. It's an ultra-high-strength steel known for its excellent strength-to-weight ratio, not extreme hardness, but rather its tough, fine-grained microstructure.
Full specification and details are available on request. The above information is provided for guidance purposes only. For specific design requirements please contact our technical sales staff
