Steel QP1180-CR (Cold rolled)
Supply condition · default condition
Default uncoated cold-rolled Q&P coil/blank for interior structural parts that are e-coated after assembly.
Values for the CR condition
Other QP1180 tempers and conditions
QP1180 is listed in 2 conditions; see the grade overview at QP1180.
- CR
- PB
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
CRDefaultThis page Cold rolled | Default uncoated cold-rolled Q&P coil/blank for interior structural parts that are e-coated after assembly. | 920 | 1,240 | 15 | 39 HRC | — |
Formed + paint baked | Represents the in-service part condition: bake hardening plus prestrain raises yield strength and slightly reduces remaining ductility. | 1,010 | 1,290 | 11 | 40 HRC | 3.8 % IACS |
What is QP1180-CR?
QP1180-CR is QP1180 supplied in the CR condition — default uncoated cold-rolled Q&P coil/blank for interior structural parts that are e-coated after assembly. QP1180-CR has a yield strength of 920 MPa (133 ksi) and a tensile strength of 1,240 MPa (180 ksi) — stronger than 90% of steel grades. Elongation at break is 15% and the elastic modulus is 207 GPa (30 Msi). QP1180-CR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F).
Advantages
- High strength — 920 MPa (133 ksi), better than 90% of steel grades
Limitations
- Difficult to machine — 22/100, worse than 95% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Low fracture toughness — 50 MPa·√m (45.5 ksi·√in), worse than 86% of steel grades
- Poor heat conductor — 28 W/m·K (16.2 BTU/hr·ft·°F), worse than 85% of steel grades
- Low electrical conductivity — 3.8 % IACS, worse than 84% of steel grades
QP1180-CR properties
Typical room-temperature values for QP1180-CR; 10 are specific to this condition. Other listed values are QP1180 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
QP1180-CR has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F).
Mechanical13
QP1180-CR has a yield strength of 920 MPa (133 ksi) and a tensile strength of 1,240 MPa (180 ksi) — stronger than 90% of steel grades. Elongation at break is 15% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
QP1180-CR is rated for continuous service to 200°C (392 °F). It conducts heat at 28 W/m·K (16.2 BTU/hr·ft·°F), worse than 85% of steel grades. Thermal expansion is 12.5 µm/m·K (6.94 µin/in·°F).
Electrical3
QP1180-CR conducts electricity at 3.8 % IACS, worse than 84% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of QP1180-CR takes about 32 MJ of energy and emits 2.4 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 25%.
Manufacturability7
QP1180-CR's machinability is poor (22/100, worse than 95% of steel grades); weldability good (60/100); formability fair (47/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with QP1180-CR
Is QP1180 easy to machine?
Avoid conventional machining of finished parts — use laser or fine blanking with hardened tool steel/carbide, generous clearance and 380 HV-rated punches to limit edge damage.
Can QP1180 be welded?
Resistance spot welding works with reduced current and long/pulsed schedules plus post-weld tempering pulse; high carbon equivalent gives hard, notch-sensitive nuggets, and Zn-coated sheet needs LME-mitigating electrode force and cooling.
Can QP1180 be formed, bent or molded?
Cold stamp with generous radii, high blank-holder force and springback compensation in die design; keep sheared edges smooth (laser or low-clearance trim) to avoid hole-expansion and delayed hydrogen cracking failures.
What surface finishes work on QP1180?
Not anodizable — protect with hot-dip/electro zinc coating, zinc-phosphate pretreatment and cathodic e-coat; avoid acid pickling and high-temperature (>250 °C) coatings that temper the partitioned microstructure.
QP1180 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 |
|---|---|---|
| Ccarbon partitioned into retained austenite | 0.17 – 0.25 | 0.2 |
| Sisuppresses carbide formation during partitioning; may be partly replaced by Al | 1.2 – 1.8 | 1.5 |
| Mn | 1.8 – 2.6 | 2.2 |
| Aldeoxidation; higher Al in Si-lean galvanizing-friendly variants | 0.02 – 0.6 | 0.05 |
| Crhardenability, optional | ≤ 0.5 | 0.2 |
| Mooptional | ≤ 0.3 | 0.1 |
| Nbgrain refinement | ≤ 0.06 | 0.03 |
| Tioptional microalloy | ≤ 0.06 | 0.02 |
| Boptional | ≤ 0 | — |
| Pimpurity limit | ≤ 0.02 | 0.01 |
| Simpurity limit | ≤ 0.01 | 0 |
| Nimpurity limit | ≤ 0.01 | 0 |
| Fe | balance | — |
QP1180-CR — frequently asked
What is QP1180-CR used for?
QP1180-CR is typically used for B-pillar reinforcements, sills and crash-critical brackets. In short: formable 1200 MPa class; third-generation AHSS; better draws than DP1180.
What is the yield strength of QP1180-CR?
QP1180-CR has a typical yield strength of 920 MPa (133 ksi) and a tensile strength of 1,240 MPa (180 ksi) — stronger than 90% of steel grades. Strength varies by condition: see the 2 listed tempers.
Is QP1180-CR easy to machine?
Not especially — machinability is rated poor (22/100, worse than 95% of steel grades). Avoid conventional machining of finished parts — use laser or fine blanking with hardened tool steel/carbide, generous clearance and 380 HV-rated punches to limit edge damage.
Can QP1180-CR be welded?
Yes — weldability is rated good (60/100). Resistance spot welding works with reduced current and long/pulsed schedules plus post-weld tempering pulse; high carbon equivalent gives hard, notch-sensitive nuggets, and Zn-coated sheet needs LME-mitigating electrode force and cooling.
What surface finishes work on QP1180-CR?
Not anodizable — protect with hot-dip/electro zinc coating, zinc-phosphate pretreatment and cathodic e-coat; avoid acid pickling and high-temperature (>250 °C) coatings that temper the partitioned microstructure.
Can QP1180-CR be formed, bent or molded?
Cold stamp with generous radii, high blank-holder force and springback compensation in die design; keep sheared edges smooth (laser or low-clearance trim) to avoid hole-expansion and delayed hydrogen cracking failures.
What is the maximum service temperature of QP1180-CR?
QP1180-CR is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between QP1180-CR and QP1180-PB?
CR is the default condition — default uncoated cold-rolled Q&P coil/blank for interior structural parts that are e-coated after assembly. PB: represents the in-service part condition: bake hardening plus prestrain raises yield strength and slightly reduces remaining ductility. Yield strength is 920 MPa in CR versus 1,010 MPa in PB.
Sources
- Q&P steel product sheets (QP980 / QP1180) — Baosteel / Ansteel / Benxi Steel (2023)
- AHSS Application Guidelines V7 — 3rd Generation Steels (Q&P) — WorldAutoSteel (2021)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- Life-cycle inventory data for cold-rolled steel coil — worldsteel association (2022)
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.