Steel S1100QL QT+SR
Heat-treated state
EN 10025-6
QT+SR = qT + stress relieved
Choose when welded or heavily flame-cut assemblies need residual-stress reduction for dimensional stability; hold below the original tempering temperature or strength drops sharply.
Values for the QT+SR condition
Other S1100QL tempers and conditions
S1100QL is listed in 3 conditions; see the grade overview at S1100QL.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
QT+SRThis page QT + stress relieved | Choose when welded or heavily flame-cut assemblies need residual-stress reduction for dimensional stability; hold below the original tempering temperature or strength drops sharply. | 1,100 | 1,300 | 11 | 40 HRC | 7.5 % IACS |
heavy gauge (>30 up to 50 mm) | Same Q&T delivery condition in the upper thickness band, where through-hardening and mid-thickness toughness are the limiting factors — check producer thickness limits before specifying. | 1,130 | 1,300 | 10 | 41 HRC | 7.5 % IACS |
QTDefault Quenched and tempered | Standard as-rolled-and-Q&T delivery condition for all EN 10025-6 S1100QL plate; use for weight-critical booms, jibs and high-stress weldments needing -40 °C toughness. | 1,150 | 1,350 | 10 | 42 HRC | — |
What is S1100QL QT+SR?
S1100QL QT+SR is S1100QL heat treated to QT+SR — choose when welded or heavily flame-cut assemblies need residual-stress reduction for dimensional stability; hold below the original tempering temperature or strength drops sharply. S1100QL QT+SR has a yield strength of 1,100 MPa (160 ksi) and a tensile strength of 1,300 MPa (189 ksi) — stronger than 93% of steel grades. Elongation at break is 11% and the elastic modulus is 210 GPa (30.5 Msi). S1100QL QT+SR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). QT is the default condition FabDigit quotes; QT+SR is available on request or by drawing note.
Advantages
- High strength — 1,100 MPa (160 ksi), better than 93% of steel grades
Limitations
- Limited ductility — 11%, worse than 89% of steel grades
- Difficult to machine — 32/100, worse than 87% of steel grades
- Limited service temperature — 250°C (482 °F), worse than 85% of steel grades
- Poor heat conductor — 32 W/m·K (18.5 BTU/hr·ft·°F), worse than 82% of steel grades
S1100QL QT+SR properties
Typical room-temperature values for S1100QL QT+SR; 22 are specific to this condition. Other listed values are S1100QL reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
S1100QL QT+SR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
S1100QL QT+SR has a yield strength of 1,100 MPa (160 ksi) and a tensile strength of 1,300 MPa (189 ksi) — stronger than 93% of steel grades. Elongation at break is 11% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
S1100QL QT+SR is rated for continuous service to 250°C (482 °F). It conducts heat at 32 W/m·K (18.5 BTU/hr·ft·°F), worse than 82% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
S1100QL QT+SR conducts electricity at 7.5 % IACS, worse than 67% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of S1100QL QT+SR takes about 30 MJ of energy and emits 2.3 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 20%.
Manufacturability6
S1100QL QT+SR's machinability is poor (32/100, worse than 87% of steel grades); weldability good (58/100); formability poor (32/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with S1100QL QT+SR
Is S1100QL easy to machine?
Machine as a ~40 HRC alloy steel: rigid setups, coated carbide, reduced speed and generous feed; drilling needs sharp cobalt/carbide tooling and coolant, and cut edges from flame cutting should be removed before machining.
Can S1100QL be welded?
Weldable with low-hydrogen consumables (matching or slightly undermatching), preheat typically 100–175 °C depending on thickness/CEV, tight heat-input limits (~1.0–1.7 kJ/mm) and immediate hydrogen control to avoid HAZ softening and cold cracking.
Can S1100QL be formed, bent or molded?
Cold bendable only with large radii (min inner radius roughly 4–5×t transverse to rolling direction), full-width die support and deburred/ground edges; hot forming destroys the Q&T properties.
What surface finishes work on S1100QL?
Shot-blast and prime or paint immediately — no natural corrosion resistance; avoid acid pickling or electroplating unless followed by hydrogen bake-out because of the high strength level.
S1100QL chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Cladle analysis max per EN 10025-6 | ≤ 0.2 | 0.16 |
| Si | ≤ 0.5 | 0.3 |
| Mn | ≤ 1.7 | 1.2 |
| PQL quality | ≤ 0.02 | 0.01 |
| SQL quality | ≤ 0.01 | 0 |
| N | ≤ 0.02 | 0.01 |
| Bhardenability booster | ≤ 0.01 | 0 |
| Cr | ≤ 1.5 | 0.6 |
| Niraised for low-temperature toughness | ≤ 2 | 1.2 |
| Mo | ≤ 0.7 | 0.5 |
| Cu | ≤ 0.5 | 0.15 |
| Nb | ≤ 0.06 | 0.03 |
| Tiprotects B from N | ≤ 0.05 | 0.02 |
| V | ≤ 0.12 | 0.05 |
| Zroptional | ≤ 0.15 | — |
| FeCEV typically 0.65–0.85 depending on thickness | balance | — |
S1100QL QT+SR — frequently asked
What is S1100QL QT+SR used for?
S1100QL QT+SR is typically used for high-strength lifting booms, mobile crane telescopic sections, heavy-lift trailer chassis, concrete pump boom arms, lifting attachments and spreader beams and weight-critical structural components. In short: highest standard EN Q&T plate; low-temperature toughness (QL); weight-critical structures.
What is the yield strength of S1100QL QT+SR?
S1100QL QT+SR has a typical yield strength of 1,100 MPa (160 ksi) and a tensile strength of 1,300 MPa (189 ksi) — stronger than 93% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is S1100QL QT+SR easy to machine?
Not especially — machinability is rated poor (32/100, worse than 87% of steel grades). Machine as a ~40 HRC alloy steel: rigid setups, coated carbide, reduced speed and generous feed; drilling needs sharp cobalt/carbide tooling and coolant, and cut edges from flame cutting should be removed before machining.
Can S1100QL QT+SR be welded?
Yes — weldability is rated good (58/100). Weldable with low-hydrogen consumables (matching or slightly undermatching), preheat typically 100–175 °C depending on thickness/CEV, tight heat-input limits (~1.0–1.7 kJ/mm) and immediate hydrogen control to avoid HAZ softening and cold cracking.
What surface finishes work on S1100QL QT+SR?
Shot-blast and prime or paint immediately — no natural corrosion resistance; avoid acid pickling or electroplating unless followed by hydrogen bake-out because of the high strength level.
Can S1100QL QT+SR be formed, bent or molded?
Cold bendable only with large radii (min inner radius roughly 4–5×t transverse to rolling direction), full-width die support and deburred/ground edges; hot forming destroys the Q&T properties.
What is the maximum service temperature of S1100QL QT+SR?
S1100QL QT+SR is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10025-6: Hot rolled products of structural steels — Flat products of high yield strength structural steels in the quenched and tempered condition — CEN (2019)
- Strenx 1100 / Weldox 1100 high-strength structural plate data sheet — SSAB (2023)
- Dillimax 1100 quenched and tempered plate — Dillinger (2022)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.