Steel AHSS-CP800
Grade
also Advanced HSS
CP800 = complex phase, 800 MPa class
High yield-to-tensile ratio with good edge-stretch and hole expansion: chassis, roll-formed sections and bumper beams.
Values for the CP800 condition
Other AHSS tempers and conditions
AHSS is listed in 14 conditions; see the grade overview at AHSS.
Compare all 14 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Cold rolled | Standard body-in-white gauge (0.6–2.5 mm) with tight thickness tolerance and best surface for exposed/structural stampings. | 380 | 630 | 27 | 13 HRC | 8.6 % IACS |
Dual phase, 590 MPa min tensile class | Entry AHSS: best stretch-formability of the DP family for reinforcements, rails and seat structures. | 380 | 630 | 27 | 190 HB | 8.4 % IACS |
HRDefault Hot rolled | Cheapest AHSS form for thicker structural parts (2–8 mm): chassis arms, wheels, seat and suspension brackets. | 400 | 620 | 24 | 12 HRC | 8.6 % IACS |
Thermomechanically controlled processed | Controlled-rolled/accelerated-cooled hot band giving fine bainitic-ferritic structure: high yield with good low-temperature toughness and weldability for structural/plate use. | 460 | 620 | 22 | 14 HRC | 8.6 % IACS |
Transformation-induced plasticity, 780 MPa class | Pick when a deep-drawn or stretch-formed part needs 780 MPa strength with DP590-level elongation and high energy absorption. | 470 | 820 | 26 | 23 HRC | 6.9 % IACS |
Ferritic-bainitic (stretch-flangeable) 590 class | Hot-rolled grade with outstanding hole expansion and fatigue for wheels, chassis arms and rim sections. | 480 | 630 | 22 | 195 HB | 8.4 % IACS |
Twinning-induced plasticity austenitic Mn steel | Use when extreme elongation and crash-energy absorption are needed; austenitic and non-magnetic, but costly and delayed-cracking sensitive. | 500 | 980 | 55 | 250 HB | — |
Dual phase, 780 MPa min tensile class | Workhorse crash-energy grade for B-pillar reinforcements, rockers and longitudinal members. | 510 | 820 | 18 | 23 HRC | 8 % IACS |
Dual phase, 980 MPa min tensile class | High-strength cold stamping grade for anti-intrusion beams and pillar reinforcements; needs springback compensation. | 700 | 1,030 | 12 | 31 HRC | 7.8 % IACS |
CP800This page Complex phase, 800 MPa class | High yield-to-tensile ratio with good edge-stretch and hole expansion: chassis, roll-formed sections and bumper beams. | 700 | 850 | 12 | 25 HRC | 7.6 % IACS |
Quenched and partitioned, 980 MPa class | Third-generation AHSS: DP980 strength with roughly double the elongation for complex cold-stamped safety parts. | 720 | 1,030 | 20 | 31 HRC | 6.9 % IACS |
Dual phase, 1180 MPa min tensile class | Top cold-formable DP class for near-hot-stamping strength in roll-formed or mild-draw parts. | 950 | 1,230 | 7 | 38 HRC | 7.6 % IACS |
Martensitic, 1300 MPa class | Roll-formed only: bumper beams, door impact bars and side-intrusion tubes needing maximum strength per mass. | 1,100 | 1,350 | 5 | 42 HRC | — |
Press-hardened (hot-stamped) 22MnB5, Al-Si coated | Hot-stamped in-die quenched martensite for A/B-pillars, roof rails and tunnels: near-zero springback and highest strength, but no cold formability and needs laser trimming. | 1,150 | 1,550 | 6 | 47 HRC | — |
What is AHSS-CP800?
AHSS-CP800 is AHSS in the CP800 grade — high yield-to-tensile ratio with good edge-stretch and hole expansion: chassis, roll-formed sections and bumper beams. AHSS-CP800 has a yield strength of 700 MPa (102 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 81% of steel grades. Elongation at break is 12% and the elastic modulus is 207 GPa (30 Msi). AHSS-CP800 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,500°C (2,732 °F). HR is the default condition FabDigit quotes; CP800 is available on request or by drawing note.
Advantages
- High strength — 700 MPa (102 ksi), better than 81% of steel grades
Limitations
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Difficult to machine — 33/100, worse than 86% of steel grades
- Limited ductility — 12%, worse than 84% of steel grades
- Low fracture toughness — 52 MPa·√m (47.3 ksi·√in), worse than 84% of steel grades
AHSS-CP800 properties
Typical room-temperature values for AHSS-CP800; 23 are specific to this condition. Other listed values are AHSS reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
AHSS-CP800 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,500°C (2,732 °F).
Mechanical17
AHSS-CP800 has a yield strength of 700 MPa (102 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 81% of steel grades. Elongation at break is 12% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
AHSS-CP800 is rated for continuous service to 200°C (392 °F). It conducts heat at 38 W/m·K (22 BTU/hr·ft·°F), worse than 69% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
AHSS-CP800 conducts electricity at 7.6 % IACS, worse than 65% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of AHSS-CP800 takes about 27 MJ of energy and emits 2.2 kg of CO₂ — less than 59% of steel grades. Typical recycled content is 25%.
Manufacturability7
AHSS-CP800's machinability is poor (33/100, worse than 86% of steel grades); weldability good (62/100); formability fair (48/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with AHSS-CP800
Is AHSS easy to machine?
Abrasive multiphase/martensitic structure — use rigid setups, coated carbide or CBN, low feed per tooth; laser or waterjet cutting is preferred over shearing above ~1000 MPa to avoid edge damage.
Can AHSS be welded?
Resistance spot weldable with adjusted (often multi-pulse) schedules and higher electrode force; watch HAZ softening in DP/MS, liquid-metal embrittlement on Zn coatings, and use low-hydrogen practice or laser welding for high-strength classes.
Can AHSS be formed, bent or molded?
Higher press loads and 2–3× the springback of mild steel; compensate die geometry, allow generous bend radii, and roll-form rather than draw grades above ~1000 MPa; press-hardening grades are formed hot at 900–950 °C and quenched in the die.
What surface finishes work on AHSS?
Not anodizable; supplied bare, hot-dip galvanized (GI/GA), Zn-Mg or Al-Si coated, then phosphated and e-coated/painted — avoid electroplating on ≥1200 MPa parts due to hydrogen embrittlement risk.
AHSS 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 |
|---|---|---|
| C0.06–0.15 for DP/TRIP/CP; up to ~0.25 for MS and 22MnB5 | 0.06 – 0.23 | 0.12 |
| Mnhigh-Mn TWIP grades contain 15–25 % Mn | 0.8 – 2.6 | 1.8 |
| Si1.0–2.0 % in TRIP/Q&P to stabilise retained austenite | 0.05 – 2 | 0.3 |
| Crhardenability | 0 – 0.6 | 0.25 |
| Moretards ferrite/pearlite | 0 – 0.5 | 0.15 |
| Aldeoxidation; up to 1.5 % in Al-alloyed TRIP | 0.02 – 1.5 | 0.05 |
| Nbgrain refinement (microalloying) | 0 – 0.06 | 0.03 |
| TiN fixing, B protection | 0 – 0.05 | 0.02 |
| Voptional precipitation strengthening | 0 – 0.1 | |
| Bessential in press-hardening 22MnB5 | 0 – 0.01 | 0 |
| P | ≤ 0.03 | 0.01 |
| S | ≤ 0.02 | 0.01 |
| N | ≤ 0.01 | 0.01 |
| Fe | balance |
AHSS-CP800 — frequently asked
What is AHSS-CP800 used for?
AHSS-CP800 is typically used for automotive crash and bumper beams, A- and B-pillar reinforcements, door impact beams, rocker panels and roof rails, seat structures and frames and chassis and suspension arms. In short: lightweight; high-strength.
What is the yield strength of AHSS-CP800?
AHSS-CP800 has a typical yield strength of 700 MPa (102 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 81% of steel grades. Strength varies by condition: see the 14 listed tempers.
Is AHSS-CP800 easy to machine?
Not especially — machinability is rated poor (33/100, worse than 86% of steel grades). Abrasive multiphase/martensitic structure — use rigid setups, coated carbide or CBN, low feed per tooth; laser or waterjet cutting is preferred over shearing above ~1000 MPa to avoid edge damage.
Can AHSS-CP800 be welded?
Yes — weldability is rated good (62/100). Resistance spot weldable with adjusted (often multi-pulse) schedules and higher electrode force; watch HAZ softening in DP/MS, liquid-metal embrittlement on Zn coatings, and use low-hydrogen practice or laser welding for high-strength classes.
What surface finishes work on AHSS-CP800?
Not anodizable; supplied bare, hot-dip galvanized (GI/GA), Zn-Mg or Al-Si coated, then phosphated and e-coated/painted — avoid electroplating on ≥1200 MPa parts due to hydrogen embrittlement risk.
Can AHSS-CP800 be formed, bent or molded?
Higher press loads and 2–3× the springback of mild steel; compensate die geometry, allow generous bend radii, and roll-form rather than draw grades above ~1000 MPa; press-hardening grades are formed hot at 900–950 °C and quenched in the die.
What is the maximum service temperature of AHSS-CP800?
AHSS-CP800 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 AHSS-HR and AHSS PHS1500?
HR is the default condition — cheapest AHSS form for thicker structural parts (2–8 mm): chassis arms, wheels, seat and suspension brackets. PHS1500: hot-stamped in-die quenched martensite for A/B-pillars, roof rails and tunnels: near-zero springback and highest strength, but no cold formability and needs laser trimming. Yield strength is 400 MPa in HR versus 1,150 MPa in PHS1500.
Can FabDigit make parts in AHSS-CP800?
Yes — AHSS-CP800 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
- Advanced High-Strength Steels Application Guidelines v7 — WorldAutoSteel (2021)
- SAE J2745 — Advanced High Strength Steel Sheet — SAE International (2019)
- VDA 239-100 — Sheet Steel for Cold Forming — VDA (2016)
- EN 10338 / EN 10346 — hot & cold rolled multiphase and coated steels — CEN (2015)
- Dual Phase, Complex Phase and Usibor product data — ArcelorMittal (2023)
- Automotive high-strength steel catalogue — Baosteel (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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.