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S690 QL/S690 QL1 high strength structural steel 2023-12-12
Condition of Delivery
Water quenched and tempered.
Typical Applications
  • Heavy road vehicles: chassis, dumper bodies.
  • Cranes construction: booms of mobile cranes. Structural.
  • steelworks: bridges, bridge components, components for offshore structures.
  • Pressure vessels: fixed and transportable storage tanks, vessels.
  • Power plants: penstocks, spiral cases.
  • Materials handling: lifting and mobile.
  • equipment. Mining and earthmoving equipment: roof supports. Agricultural equipment and trailers.
Chemical Composition (Heat analysis in %)
C Si Mn P S Cr Mo Ni Al
≤0.2 ≤0.8 ≤1.70 ≤0.020 ≤0.005 ≤1.50 ≤0.70 ≤2.0 ≤0.100
Mechanical Properties
Plate Thickness
mm
Yield Point Re
MPa
Tensile Strength Rm
MPa
Elongation at Rupture A5 %
≤ 50 690 770 – 940 14
> 50 ≤ 100 650 760 – 930 14
> 100 ≤ 150 630 710 – 900 14
Notch Impact Energy
Steel Grade Position of Samples 0°C -20°C -40°C -60°C
S690Q Longitudinal 40 J 30 J
Transverse 30 J 27 J
S690QL Longitudinal 50 J 40 J 30 J
Transverse 35 J 30 J 27 J
S690QL1 Longitudinal 60 J 50 J 40 J 30 J
Transverse 40 J 35 J 30 J 27 J
Number of Tests

Tensile test and impact test (3 samples) every 40 t or per heat treatment unit respectively.

Processing
Cold-Forming

The steel is suitable for cold-forming adhering to a bending or folding radius of > 4 times plate thickness longitudinal and > 3 times plate thickness transverse to rolling direction. A subsequent stress relief annealing is possible up to a temperature of 580°C.

Hot-Forming

Hot-forming above 580°C is possible. A subsequent quenching and tempering has to be carried out according to the delivery condition.

Milling

Drilling with cobalt-alloyed high-speed steels HSSCO, the cutting speed should be approximately 17 – 19 m/min. If HSS drills are used, it should be approximately 3 – 5 m/min. cutting speed should be approximately 3 – 5 m/min.

Flame-Cutting

The material temperature should be at least room temperature. We recommended the following preheating temperatures: for plate thicknesses > 40mm up to 100°C, > 80mm up to 150°C and > 100mm up to 175°C.

Welding

The steel is suitable for all known welding methods. The material temperature should be at least room temperature. We recommended the following preheating temperatures: for plate thicknesses > 20mm up to 75°C, > 40mm up to 100°C, > 60mm up to 150°C and > 100mm up to 175°C. Interpass temperature should be between 150°C – 225°C.

These indications are standard values only. In general indications of SEW 088 should be adhered to. The t8/5 times should be between 5 and 15 s, depending on the welding technique used. A subsequent stress relief annealing for constructional reasons should be done in the temperature range of 530°C – 580°C.