Docol complex phase steel: high yield strength, bendability & stretch-flangeability

Docol® complex phase steels enable complex flanges with high resistance to edge cracking —ideal for lightweight, strong, crash-relevant automotive components.

Main characteristics of Docol complex phase steel

  • High-strength Docol complex phase steels facilitate the lightweighting of auto components for high crash-energy absorption.

  • Improved cleanliness provides excellent edge ductility and tight radii bendability.

  • Very high hole expansion ratios and stretch flangeability for resistance to edge cracking.

  • Highly suitable for deep-drawn components with complex geometries.

  • Excellent for cost-efficient cold forming of intricate auto parts.

Docol® HR800CP+HER

Extremely high edge ductility, with 70% typical hole expansion ratios

To reduce the risk of cracked formed edges, SSAB has introduced our newly improved Docol® HR800CP and new HR800CP+HER. The +HER means we’ve tested every shipment to guarantee a minimum of 45% hole expansion ratio — with typical valves of 70% HER. These new high edge ductility AHSSs can step in as “problem-solvers.” Or, they can even be used on auto parts where you want higher confidence that you won’t have cracked edges.

Control arm

Applications for Docol® complex phase steels

Docol® CP can be used in numerous automotive components that require both high edge ductility and good fatigue properties. Control arms, particularly lower control arms, can be an excellent complex phase application, as can multilink suspensions, trailing arms, torsion beams, and subframes — wherever parts are constantly moving and been shaken. Additional applications include chassis and select body-in-white applications, such as seat tracks and seat recliners; please check out our AHSS automotive applications page.

For supreme high edge ductility properties there is also Docol® HE (High Edge).

Body in white

Grades and mechanical properties for Docol complex phase steel

For best weight reduction, use high grades with reduced thicknesses.

Corrosion-resistant availability for Docol complex phase grades

Electrogalvanized (EG): Docol 1000CP and Docol 1200CP.

Hot-dip galvanized (GI, or Z in EN standard): Docol 600CP, Docol 800CP, and Docol 1000CP.

Galvannealed (GA, or ZF in EN standards): Docol 600CP and Docol 800CP.

Galfan (ZA): Docol 600CP and Docol 800CP.

Uncoated grades are also available, including Docol 800CP, Docol 1000CP, and Docol 1200CP.

Docol 600CP GI, GA, ZA T: 0.7– 2.5 mm
W: Up to 1520 mm
Docol 800CP UC, GI, GA, ZA T: 0.5–4 mm
W: W: Up to 1530 mm
Docol 1000CP UC, EG, GI T: 0.5–2.1 mm
W: Up to 1530 mm
Docol 1200CP UC T: 1–1.8 mm VDA239-100:2016

Forming Docol complex phase steel

  • Outstanding ISO hole expansion ratios allows stretch flanging and stretch bending, as well as punched flanges, without edge cracking.

  • Improved cleanliness allows deep drawing and tight radius forming.

  • With exceptional bending properties and formability, all Docol complex steels are suitable for cold forming of critical auto safety components.

  • Excellent for roll forming

  • Good weldability, including resistance spot welding.

Do you have other manufacturability questions about our complex phase steels? Our Technical Support can provide specific CP steel forming guidance for your automotive component.

Forming Docol Complex Phase steel

Additional benefits from Docol complex phase steel

  • Good fatigue properties for all vehicles: ICE, hybrid, or BEV.

  • Docol complex phase steels come in four strength categories — 600MPa, 800MPa, 1000MPa, and 1200MPa — with a total of 14 different grade variations carried as “standards.”

  • Additional customized grades are available to meet OEM-specific certifications.

  • Corrosion resistance coatings available on all complex phase grades.

  • Global availability and support.

  • Lean C-Mn base composition.

  • Excellent uniform ductility (see our article about elongation).

  • Bake-hardenable.

OEM-specific complex phase steels

Docol® complex phase steels are made according VDA, EN, or SSAB specifications in 14 standard offerings. In addition, we work closely with auto OEMs to develop innovative, customized, complex phase steels for your specific car components.

Why Docol complex phase steel matters to you

Safety engineers: Specify AHSS, UHSS, or gigapascal complex phase steels for high-performance energy-absorption in passive safety systems.

Lightweighting engineers: Select high-strength complex phase steels to create lightweight, thin-wall auto components that don’t sacrifice functionality.

Production engineers: Deliver complex shape components — e.g., stretched flanges with punched holes and tight radii — with high repeatability. Fully leverage cold-forming operations to save energy and processing time while increasing production line flexibility.

Procurement officers: Achieve 2x to 3x material cost reductions without performance penalties by replacing expensive aluminum or carbon fiber reinforced polymers (CFRPs).

Sustainability officers: Substantially lower the embedded CO2 in your critical safety components by replacing aluminum and CFRPs with SSAB’s industry-leading, lower CO2 AHSS/UHSS/gigapascal steels.

Lower your embedded CO2

Docol complex phase steel is “future proofed”.


Try it for yourself

Our Trial Material Stock Center is a unique service to the automotive industry. We ship coils, sheets, and custom lengths of any size to anywhere in the world. In 1-2 weeks the material is ready for dispatch.