Steel S960Q QT-L1
Heat-treated state
EN S960Q · GB Q960Q
QT-L1 = s960QL1
Cleanest/toughest variant for -60 °C design temperature or demanding CTOD requirements; longer lead time and premium price.
Values for the QT-L1 condition
Other S960Q tempers and conditions
S960Q is listed in 5 conditions; see the grade overview at S960Q.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Stress relieved | Post-fabrication stress relief for heavily welded/cold-formed weldments; keep below the original tempering temperature or strength drops sharply. | 950 | 1,010 | 14 | 31 HRC | 7.5 % IACS |
Q&T heavy plate, t > 50–100 mm (reduced guaranteed strength) | Use for heavy sections; mass effect lowers the guaranteed yield/tensile and toughness — confirm values with the mill certificate. | 960 | 1,010 | 13 | 32 HRC | 7.5 % IACS |
QTDefault Quenched and tempered | Standard as-delivered plate for ambient/moderately cold service; the normal stocked condition. | 1,000 | 1,050 | 13 | 33 HRC | — |
S960QL | Pick when the structure sees service or design temperatures down to -40 °C (mobile cranes, arctic-duty machinery). | 1,000 | 1,050 | 13 | 33 HRC | 7.5 % IACS |
QT-L1This page S960QL1 | Cleanest/toughest variant for -60 °C design temperature or demanding CTOD requirements; longer lead time and premium price. | 1,000 | 1,050 | 14 | 33 HRC | 7.5 % IACS |
What is S960Q QT-L1?
S960Q QT-L1 is S960Q heat treated to QT-L1 — cleanest/toughest variant for -60 °C design temperature or demanding CTOD requirements; longer lead time and premium price. S960Q QT-L1 has a yield strength of 1,000 MPa (145 ksi) and a tensile strength of 1,050 MPa (152 ksi) — stronger than 92% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi). S960Q QT-L1 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-L1 is available on request or by drawing note.
Advantages
- High strength — 1,000 MPa (145 ksi), better than 92% of steel grades
Limitations
- Difficult to machine — 33/100, worse than 86% 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
- High embodied carbon — 2.5 kg CO₂/kg, worse than 82% of steel grades
- Limited ductility — 14%, worse than 75% of steel grades
S960Q QT-L1 properties
Typical room-temperature values for S960Q QT-L1; 23 are specific to this condition. Other listed values are S960Q reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
S960Q QT-L1 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
S960Q QT-L1 has a yield strength of 1,000 MPa (145 ksi) and a tensile strength of 1,050 MPa (152 ksi) — stronger than 92% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
S960Q QT-L1 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
S960Q QT-L1 conducts electricity at 7.5 % IACS, worse than 67% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (13/100), better than 66% of steel grades.
Sustainability4
Producing a kilogram of S960Q QT-L1 takes about 32 MJ of energy and emits 2.5 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 25%.
Manufacturability7
S960Q QT-L1's machinability is poor (33/100, worse than 86% of steel grades); weldability good (58/100); formability fair (38/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with S960Q QT-L1
Is S960Q easy to machine?
Machine as a ~320 HB Q&T steel: rigid setups, coated carbide, moderate speed with heavy positive feed; avoid rubbing and keep flame-cut edges (hard HAZ) out of the cut where possible.
Can S960Q be welded?
Low-hydrogen consumables only (matching or slightly undermatching), preheat typically 100–175 °C by thickness/CEV, interpass ≤ 200 °C, controlled heat input ≈ 1.0–1.7 kJ/mm to protect HAZ toughness; dry and clean the joint to avoid hydrogen cracking.
Can S960Q be formed, bent or molded?
Cold-bend transverse to rolling direction with generous punch radii (≈3–4 t for thin plate, more for thick), allow high springback and press force; hot forming above ~580 °C destroys the Q&T properties and requires re-heat treatment.
What surface finishes work on S960Q?
Not corrosion resistant — shot blast to Sa 2½ and paint or zinc-rich prime; avoid acid pickling and standard hydrogen-generating electroplating unless a post-plate bake (190–220 °C) is applied.
S960Q 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, EN 10025-6 | ≤ 0.2 | 0.17 |
| Si | ≤ 0.8 | 0.35 |
| Mn | ≤ 1.7 | 1.3 |
| PQL/QL1: ≤0.020 | ≤ 0.03 | 0.01 |
| SQL/QL1: ≤0.010 | ≤ 0.02 | 0 |
| N | ≤ 0.02 | 0.01 |
| Bboron for hardenability | ≤ 0.01 | 0 |
| Cr | ≤ 1.5 | 0.6 |
| Cu | ≤ 0.5 | 0.15 |
| Mo | ≤ 0.7 | 0.5 |
| Nb | ≤ 0.06 | 0.03 |
| Ni | ≤ 2 | 1 |
| Ti | ≤ 0.05 | 0.02 |
| V | ≤ 0.12 | 0.05 |
| Zr | ≤ 0.15 | — |
| Altotal Al, min for grain refinement | ≥ 0.02 | 0.04 |
| FeCEV ≤ 0.82 for t ≤ 50 mm | balance | — |
S960Q QT-L1 — frequently asked
What is S960Q QT-L1 used for?
S960Q QT-L1 is typically used for mobile crane telescopic booms, high-strength trailers and off-highway equipment. In short: highest standard EN Q&T grade; 1000 MPa yield plate; minimum-weight boom steel.
What is the yield strength of S960Q QT-L1?
S960Q QT-L1 has a typical yield strength of 1,000 MPa (145 ksi) and a tensile strength of 1,050 MPa (152 ksi) — stronger than 92% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is S960Q QT-L1 easy to machine?
Not especially — machinability is rated poor (33/100, worse than 86% of steel grades). Machine as a ~320 HB Q&T steel: rigid setups, coated carbide, moderate speed with heavy positive feed; avoid rubbing and keep flame-cut edges (hard HAZ) out of the cut where possible.
Can S960Q QT-L1 be welded?
Yes — weldability is rated good (58/100). Low-hydrogen consumables only (matching or slightly undermatching), preheat typically 100–175 °C by thickness/CEV, interpass ≤ 200 °C, controlled heat input ≈ 1.0–1.7 kJ/mm to protect HAZ toughness; dry and clean the joint to avoid hydrogen cracking.
What surface finishes work on S960Q QT-L1?
Not corrosion resistant — shot blast to Sa 2½ and paint or zinc-rich prime; avoid acid pickling and standard hydrogen-generating electroplating unless a post-plate bake (190–220 °C) is applied.
Can S960Q QT-L1 be formed, bent or molded?
Cold-bend transverse to rolling direction with generous punch radii (≈3–4 t for thin plate, more for thick), allow high springback and press force; hot forming above ~580 °C destroys the Q&T properties and requires re-heat treatment.
What is the maximum service temperature of S960Q QT-L1?
S960Q QT-L1 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.
What is the difference between S960Q-QT and S960Q-SR?
QT is the default condition — standard as-delivered plate for ambient/moderately cold service; the normal stocked condition. SR: post-fabrication stress relief for heavily welded/cold-formed weldments; keep below the original tempering temperature or strength drops sharply. Yield strength is 1,000 MPa in QT versus 950 MPa in SR.
Sources
- EN 10025-6 Hot rolled products of structural steels — Part 6: Flat products of high yield strength structural steels in the quenched and tempered condition — CEN (2019)
- Strenx 960E/F structural steel data sheet — SSAB (2023)
- XABO 960 quenched and tempered fine-grain plate — thyssenkrupp Steel (2022)
- alform 960 M / alform plate technical data — voestalpine (2021)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- GB/T 16270 High strength structural steel plates in the quenched and tempered condition (Q960) — SAC (2009)
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.