Steel DP780
DP780 is an advanced high-strength dual-phase (ferrite + martensite) sheet steel of the 780-900 MPa tensile class, continuously annealed and rapidly cooled to form 25-35% martensite islands in a soft ferrite matrix.
Values for the CR condition
DP780 tempers and conditions
DP780 is supplied in 2 conditions, soft to hard. CR is the default FabDigit quotes; the values on this page are for it.
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
CRDefault Cold rolled | Standard uncoated cold-rolled DP780 sheet for painted/e-coated interior structural stampings. | 500 | 830 | 16 | 245 HB | — |
Hot rolled | Use for chassis, control arms and wheel discs where gauge above ~2.5 mm is needed and surface finish is secondary. | 520 | 840 | 15 | 25 HRC | 8.6 % IACS |
Supply forms, finishes and certifications
Ways DP780 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
EG | Electrogalvanized zinc coated | Coating |
GA | Galvannealed zinc-iron coated | Coating |
Galvanized | Hot-dip zinc coated | Coating |
What is DP780?
DP780 is an advanced high-strength dual-phase (ferrite + martensite) sheet steel of the 780-900 MPa tensile class, continuously annealed and rapidly cooled to form 25-35% martensite islands in a soft ferrite matrix. High strength with a high initial work-hardening rate, good formability and spot weldability makes it a standard body-in-white lightweighting sheet, supplied CR, HR and GI/GA/EG coated; the default is 500 MPa yield, 830 MPa tensile, 16% elongation, 245 HB. Springback and sheared-edge cracking need attention, corrosion resistance equals plain carbon steel so zinc coating or paint is required, and above about 250 °C the martensite tempers. DP780 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,490°C (2,714 °F). DP780 has a yield strength of 500 MPa (72.5 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 63% of steel grades. Elongation at break is 16% and the elastic modulus is 207 GPa (30 Msi).
What is DP780 used for?
- B-pillar reinforcements
- Bumper beams and bumper beam brackets
- Longitudinal frame rails
- Seat frames
- Body cross members
- Door impact beams
- Floor and wheelhouse reinforcements
Advantages
- Readily welded — 72/100, better than 75% of steel grades
Limitations
- Limited service temperature — 250°C (482 °F), worse than 85% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
DP780 properties
Typical room-temperature values for DP780-CR; bars are the position among steel grades.
Physical3
DP780 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,490°C (2,714 °F).
Mechanical14
DP780 has a yield strength of 500 MPa (72.5 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 63% of steel grades. Elongation at break is 16% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
DP780 is rated for continuous service to 250°C (482 °F). It conducts heat at 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 64% of steel grades. Thermal expansion is 12.5 µm/m·K (6.94 µin/in·°F).
Electrical3
DP780 conducts electricity at 8.6 % IACS, better than 66% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of DP780 takes about 30 MJ of energy and emits 2.3 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 25%.
Manufacturability6
DP780's machinability is fair (42/100, worse than 73% of steel grades); weldability very good (72/100); formability good (55/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. DP780 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with DP780
Is DP780 easy to machine?
Rarely machined; drilling/trimming needs sharp carbide or laser cutting — trimmed edges are notch-sensitive and should be deburred to avoid edge cracking.
Can DP780 be welded?
Good resistance spot weldability with reduced current and longer hold/post-pulse to limit HAZ softening and interfacial fracture; laser and MAG welding fine, avoid heavy heat input that tempers the martensite.
Can DP780 be formed, bent or molded?
High n-value gives good stretch forming but expect 2–3× the springback of mild steel — compensate dies, use over-crown/post-stretch, and keep generous bend radii (≥3–4 t) with burr-free blanks.
Manufacturability
The process limits FabDigit applies to DP780. Every DP780 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
Sheet metal
| Formability | Better55 / 100 |
|---|---|
| Weldability | Excellent72 / 100 |
| Bendable | Yes |
DP780 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 |
|---|---|---|
| Ccontrols martensite hardness | 0.08 – 0.18 | 0.13 |
| Mnhardenability | 1.2 – 2.5 | 1.9 |
| Si | 0.1 – 0.8 | 0.35 |
| CrCr+Mo typically ≤1.0 combined | 0 – 0.8 | 0.25 |
| Mosuppresses pearlite on cooling | 0 – 0.4 | 0.15 |
| Aldeoxidation | 0.02 – 0.1 | 0.04 |
| Nbgrain refinement (optional) | 0 – 0.1 | 0.02 |
| Tioptional microalloy | 0 – 0.15 | 0.02 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.02 | 0.01 |
| Boptional | 0 – 0.01 | 0 |
| Fe | balance |
What surface finishes work on DP780?
Zinc coating (GI/GA/EG) plus phosphate and e-coat is the standard protection route; bare CR must be oiled in storage and painted in service, no anodizing applies.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
Black / Phosphate
Thermal Spray
How much does DP780 cost?
DP780 is a standard-cost steel ($$), cheaper than about 61% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
DP780 — frequently asked
What is DP780 used for?
DP780 is typically used for B-pillar reinforcements, bumper beams and bumper beam brackets, longitudinal frame rails, seat frames, body cross members and door impact beams. In short: workhorse dual-phase sheet.
What is the yield strength of DP780?
DP780 has a typical yield strength of 500 MPa (72.5 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 63% of steel grades. Strength varies by condition: see the 2 listed tempers.
Is DP780 easy to machine?
Not especially — machinability is rated fair (42/100, worse than 73% of steel grades). Rarely machined; drilling/trimming needs sharp carbide or laser cutting — trimmed edges are notch-sensitive and should be deburred to avoid edge cracking.
Can DP780 be welded?
Yes — weldability is rated very good (72/100). Good resistance spot weldability with reduced current and longer hold/post-pulse to limit HAZ softening and interfacial fracture; laser and MAG welding fine, avoid heavy heat input that tempers the martensite.
What surface finishes work on DP780?
Zinc coating (GI/GA/EG) plus phosphate and e-coat is the standard protection route; bare CR must be oiled in storage and painted in service, no anodizing applies.
Can DP780 be formed, bent or molded?
High n-value gives good stretch forming but expect 2–3× the springback of mild steel — compensate dies, use over-crown/post-stretch, and keep generous bend radii (≥3–4 t) with burr-free blanks.
What is the maximum service temperature of DP780?
DP780 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 DP780-CR and DP780-HR?
CR is the default condition — standard uncoated cold-rolled DP780 sheet for painted/e-coated interior structural stampings. HR: use for chassis, control arms and wheel discs where gauge above ~2.5 mm is needed and surface finish is secondary. Yield strength is 500 MPa in CR versus 520 MPa in HR.
How much does DP780 cost?
DP780 is a standard-cost steel ($$), cheaper than about 61% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in DP780?
Yes — DP780 is available for sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- EN 10346 — Continuously hot-dip coated steel flat products (HCT780X) — CEN (2015)
- SAE J2745 — Steel, High Strength, Dual Phase, Cold Rolled and Coated Sheet — SAE International (2018)
- GB/T 20564.2 — Cold rolled dual phase steel sheet for automobile — SAC (2017)
- Advanced High-Strength Steels Application Guidelines V7 — WorldAutoSteel (2021)
- Dual phase steel DP780 / DP800 cold rolled and coated data sheets — ArcelorMittal / Baosteel / voestalpine (2023)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels — ASM International (1990)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.