What is the hardness of S690QL1steel?

S690QL1 steel, a high-strength quenched and tempered structural steel, doesn't have a fixed hardness requirement but typically exhibits a Brinell Hardness (BHN) range of around 235-295 BHN, though this is a typical value for information and not a mandatory test parameter, focusing instead on its high yield strength (690 MPa) and excellent toughness at low temperatures (down to -60°C) for demanding applications.

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S690QL1 is a European standard (EN 10025-6) high-strength quenched and tempered structural steel, known for its minimum yield strength of 690 MPa, good weldability, and excellent impact toughness at very low temperatures (down to -60°C), making it ideal for heavy-duty components in construction, mining, and heavy vehicles where lightness and strength are crucial. The designation breaks down as: 'S' for structural, '690' for 690 MPa yield strength, 'Q' for quenched, 'L' for normalized (or controlled rolled), and '1' indicating a specific low-temperature impact test requirement.

In the realm of offshore and marine engineering, S690QL1 is indispensable for the construction of jack-up rigs, offshore platforms, and wind turbine foundations. These structures are frequently exposed to the harsh, corrosive environments of the open sea and must endure the dynamic loads of waves and wind. The "L1" designation is vital here, as it guarantees that the steel remains tough and resistant to brittle fracture even in the freezing temperatures of Arctic or North Sea waters. Similarly, in the mining and earthmoving industries, S690QL1 is used for the chassis of heavy-duty dump trucks, excavator buckets, and wear-resistant parts. The steel's ability to absorb energy and resist impact ensures that equipment can operate reliably in the most demanding geological conditions without catastrophic failure.

Key Characteristics:

High Strength: Minimum yield strength of 690 MPa (megapascals).

Heat Treatment: Delivered in a quenched and tempered (Q&T) condition for enhanced properties.

Low-Temperature Toughness: The 'L1' signifies it's impact-tested at -60°C, providing superior performance in cold environments compared to S690QL (-40°C).

Good Weldability: Pure steel with low harmful elements (P, S) results in good welding performance.

Fine-Grained: Often produced with controlled rolling for maximum performance.

Common Applications:

Cranes (booms)

Bridges and structural steelworks

Mining and excavation machinery (roof supports, dump bodies)

Heavy-duty vehicles (chassis, dumper bodies)

Offshore structures and pressure vessels

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What is the yield strength of S690QL1 ?

S690QL1, a high-strength structural steel, has a minimum yield strength (ReH) of 690 MPa for thicknesses up to 50mm, decreasing to 650 MPa (50-100mm) and 630 MPa (100-150mm), according to EN 10025-6 standard, ensuring strong performance in heavy-duty, cold-weather applications.

What are common testing requirements for S690QL1?

Common testing requirements for S690QL1, a high-strength structural steel, focus on its key properties: minimum 690 MPa yield strength, 770-940 MPa tensile strength, and crucial -60°C impact toughness (QL1 designation), verified through tensile tests and longitudinal Charpy-V notch impact tests on heat-treated plates, ensuring performance in demanding, cold environments, with testing typically per EN 10025-6 standard.

What is the best way to cut S690QL1?

The best way to cut S690QL1 depends on the plate thickness and the required precision, but Laser Cutting and Plasma Cutting are the most common industrial choices. For plates up to 25mm, Laser Cutting is ideal because it offers extreme precision and a narrow Heat Affected Zone (HAZ), which helps preserve the steel's specialized quenched and tempered properties. For thicker plates, High-Definition Plasma Cutting is highly effective, offering a balance of speed and cost-efficiency. If you need to avoid heat entirely to ensure the mechanical integrity of the "L1" (low-temperature toughness) grade remains 100% unchanged, Abrasive Waterjet Cutting is the superior "cold" method, as it prevents any thermal softening. When using thermal methods like Oxy-fuel, it is critical to preheat thicker plates (typically above 40mm) to around 100°C to 175°C to prevent edge cracking.

S690QL1Chemical Composition
Grade	The Element Max (%)
Grade	C	Si	Mn	P	S	N	B	Cr
S690 QL1	0.20	0.80	1.70	0.020-0.025	0.010-0.015	0.015	0.005	1.50
	Cu	Mo	Nb	Ni	Ti	V	Zr
	0.50	0.70	0.06	2.0	0.05	0.12	0.15

Grade	S690QL1Mechanical Property
Grade	Thickness	Yield	Tensile	Elongation
S690 QL1	mm	Min Mpa	Mpa	Min %
	3	890	940-1100	11
	50	830	880-1100	11
	100	800	820-1000	11

S690QL1 Steel Plate Notch Impact Energy

Steel Grade	Position of Samples	0°C	- 20°C	- 40°C	- 60°C
S690QL1/MAXIL® 690 QL1	LongitudinalTransverse	60 J40 J	50 J35 J	40 J30 J	30 J27 J

1 How heavy is S690QL1?

S690QL1, a high-strength structural steel, doesn't have a single weight; its weight depends on its dimensions (length, width, thickness), but a standard density of around 0.2836 pounds per cubic inch (or about 40.8 lbs per square foot per inch of thickness) allows calculation, so a 1-inch thick plate would weigh roughly 40.8 pounds for every square foot of surface area, with heavier weights for thicker or larger pieces.

2 What are the typical application fields of S690QL1?

S690QL1, a high-yield strength, quenched, and tempered steel, is used in heavy-duty, high-stress applications where weight saving and durability are crucial, such as cranes (booms, jibs), heavy construction equipment (excavators, bulldozers), bridges, offshore structures, mining machinery, truck chassis, and pressure vessels, benefiting from its high strength-to-weight ratio, excellent toughness at low temperatures (down to -60°C), and good weldability for lighter, stronger designs.

3 What is S690QL1 equivalent to?

S690QL1 (EN 10025-6) is a high-strength, quenched, and tempered structural steel with a minimum yield strength of 690 MPa, and its common equivalents include ASTM A514, ASTM A709 Grade 100, ASTM A710, German EStE690V (DIN/WNr 1.8988), French E690T, and Swedish SS 2625 (Weldox 700), though exact interchangeability requires engineering confirmation due to specific code requirements.

4 What is the difference between S690QL1 and S690QL?

The main difference between S690QL and S690QL1 is their specified minimum impact toughness at lower temperatures: S690QL is tested at -40°C, while S690QL1 is tested at a more extreme -60°C, making S690QL1 superior for applications in exceptionally cold environments requiring higher impact energy absorption. Both are high-strength, quenched, and tempered (Q&T) structural steels with a minimum yield strength of 690 MPa, excellent weldability, and toughness, but the "L1" designation signifies enhanced low-temperature performance.

5 What temperature is S690QL1 steel?

S690QL1 steel is designed for low-temperature service, specifically meeting impact toughness requirements at -60°C (-76°F), making it excellent for cold environments, with typical operating temperatures ranging from roughly -60°C up to 350°C, though its properties (like yield strength) decrease at higher temperatures, and it requires preheating for welding and quenching/tempering after hot forming.