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Docol high strength steel

Docol in applications

Use Docol® advanced high-strength steel for stronger, safer steel applications in the auto industry.

Many industries are realizing the benefits of advanced high-strength and ultra-high strength steels as new grades continue to evolve and grow in application. Docol steel from SSAB is an integral part of this evolution. This advanced, high-performance steel makes it possible to produce thinner profiles that can withstand higher loads.

The many new steel grades serve specific design purposes and are picked by designers for certain applications. The most important parameters are derived from the geometrical form of the component and the selection of forming and blanking method.

Automotive industry applications

New formulations and grades of high-performance steels enable auto makers to produce vehicles that are stronger, lighter and more energy efficient.

Docol AHSS has been used successfully in applications like these for the automotive industry:

Docol in bumpers

Bumpers

Shape Corp., a leading automotive supplier in the arena of impact energy management, has been using Docol AHSS in their bumpers for many years. It allows for thinner steel gauges and reduced steel consumption by up to 20 percent. Their latest design for bumpers will enable even more weight reduction.


Read our case study about a bumper application

Docol in bumpers help shed weight and improve bumper performance

Today, as automakers and suppliers struggle to meet conflicting requirements — tougher impact and fuel economy regulations at a lower cost to the end consumer — they’re turning to advanced high-strength steel for creative solutions. AHSS is paving the way toward reducing weight and improving application performance.

MonoLeg’s closed tubular structure improves torsion stiffness, the center leg improves bending and buckling resistance.

Shape Corp., a leading automotive supplier in impact energy management, has been using Docol® AHSS in its Power B-Section bumper for many years. It allows for thinner steel gauges and reduced steel consumption by up to 20 percent. Shape Corp’s MonoLeg bumper, based on an exciting new design, offers the performance and mass of an aluminum bumper, with the cost advantage of a steel solution.

Designed for better impact performance

Updates to the IIHS and RCAR bumper test protocols include impacting beams into barriers that more realistically mimic other vehicle bumper. Shape Corp. designed a geometry that counteracts both the torsion and bending demands of the IIHS and RCAR bumper test protocols. Blending the strength of the Shape Corp. Power-B bumper with the torsion strength of tubular sections, the MonoLeg improves torsion strength by 50% to combat the combined loading effect of these impacts.

Engineered to be lightweight

By taking advantage of the high mechanical properties of AHSS and applying them to an optimal geometric design, the MonoLeg helps achieve fuel economy demands, including CAFE standards. A reduction in mass from a conventional steel bumper is achieved by roll forming the Shape MonoLeg bumper from AHSS, up to 1700 MPa. The characteristics of the Shape MonoLeg bumper can match those of 7000 aluminum alloys.

Force deflection curves from IIHS bumper barrier impacts demonstrate the effectiveness of the MonoLeg vs. traditional lightweight

Balanced results

This makes the Shape MonoLeg a key product for OEMs trying to balance mass reductions to meet CAFE, achieve the performance to meet impact regulations and maintain a reasonable price point.

Benefits for bumpers using Docol AHSS

The question of strength-to-weight ratio versus cost plays a key role in choosing bumper materials. Docol steel helps you resolve this issue, bringing you the following benefits:

  • Using Docol AHSS in automotive bumpers can not only reduce vehicle weight while maintaining crash test performance, but it can save you money. 
  • Docol AHSS exhibits a pronounced yield strength increase of about 150 MPa or more after work-­hardening and bake-­hardening. 
  • Docol AHSS exhibits a strain rate hardening effect. This effect corresponds to an increase of about 100 MPa at the high strain rates that are involved locally in a crash event.


Related products

Docol 1700 M

Docol sill chassis

Chassis

When Chrysler wanted to reduce the mass of the upper control arm (UCA) in its Dodge Ram pickup truck, the company turned to a higher strength steel. In order to improve its fuel economy in times of rising gasoline prices, the full-size pickup truck underwent a massive mass reduction. This had to be accomplished without giving up the truck’s load carrying or towing capabilities — two critical reasons why customers buy full-size pickup trucks. One clear solution emerged: use a new design with a smaller section modulus, made from significantly higher strength steel.


Read our case study about a chassis application

Higher strength steel helps lightweight a chassis

A leading manufacturer of stamped automotive parts in the United States was challenged to come up with a front-suspension upper-control arm (UCA) for the automotive giant Chrysler. To lightweight this component, the company turned to a higher strength steel.

The challenge

Iroquois Industries Inc., of Warren, Michigan, had already been producing a front-suspension UCA for the Dodge Ram pickup truck. But in the face of rising gasoline prices and fuel economy demands, Chrysler wanted to reduce the UCA’s mass in the Dodge Ram 2009 pickup. The mass reduction program had to be accomplished without giving up the truck’s load carrying or towing capabilities — two critical reasons why customers buy full-size pickup trucks.

Upper-control arm (UCA) in high-strength steel for pickup trucks  Upper-control arm (UCA) in high-strength steel for pickup trucks

The front suspension upper control arm main stamping is made of Domex 700 M "with folded under construction" resulting in a saving of 2.72 kg (6 lbs) per vehicle.

Chrysler Purchasing and Engineering dictated that the DS UCA had to have its mass reduced to match the mass of a proposed formed-wire UCA made from cold-drawn steel wire. This arm was 1.3 kg (2.9 lbs) lighter than the DR UCA that Iroquois was producing at the time for the production Dodge Ram pickup.

The solution

One clear solution emerged: use a new design with a smaller section modulus, made from significantly higher strength steel.

The steel Iroquois selected was SSAB’s Domex 700 MC. Domex 700 MC steel is an hot rolled ultra-high strength HSLA steel with a yield strength of 700 MPa, which is twice the 340 MPa yield strength HSLA steel used on the former Dodge Ram DR UCA. Since the loading on the UCA was along the plane of the arm, it was clear that a design that maintained about the same plane view shape as the former DR UCA but with a thinner section would offer a more efficient design.

The result? The DS UCA is 1.36 kg (3 lbs) lighter than the DR UCA, and it achieved the Chrysler mass target for the arm, at the same time as the functional requirements are fulfilled. This saves 2.72 kg (6 lbs) per vehicle.


    Docol in door beams

    Door beams

    Gestamp is an international group that designs, develops and manufactures metal components and structural systems for the automotive industry. As part of its product offering, Gestamp produces a unique side-impact beam solution for a well-known car manufacturer, cold rolled in 1200 MPa steel. Gestamp agreed with SSAB to run a trial with Docol® 1400 MZE steel for the same application.

    The result? A side-impact beam that met the same technical and quality standards but with lower weight and better cost efficiency using Docol 1400 MZE.


    Read our case study about a side-impact door beam application

    Car door beams become safer, lighter and more cost effective

    Gestamp is an international group that designs, develops and manufactures metal components and structural systems for the automotive industry. Gestamp Automotion manufactures to only the highest quality and safety standards, and expects its suppliers and partners like SSAB to have the same ambitions.

    As part of its product offering, Gestamp produces a unique side-impact beam solution for a well-known car manufacturer, cold rolled in 1200 MPa steel. Gestamp agreed with SSAB to run a trial with Docol® 1400 MZE steel for the same application. The result? A side-impact beam that meet the same technical and quality standards but with a lower weight and better cost efficiency by using Docol 1400 MZE.

    The manufacturing process ran smoothly with the same performance as for the cold-rolled 1200 MPa steel using the same settings during production without any problems. No investments were needed in order to use Docol 1400 MZE.

    Top crash-test ratings at half the weight

    The unique strength of Docol AHSS increases the chances of obtaining the highest possible crash rating while reducing vehicle weight. Its best-in-class energy absorption and outstanding strength also provide many environmental benefits. In today’s market, this directly translates to greater competitiveness and higher sales.

    Whether you are looking to change steel grades or begin using Docol AHSS, you can be rewarded with weight reductions of up to 50 percent. And, you can reduce material consumption and cost through thinner grades of steel.

    Here are some strong reasons why Docol steel is optimal for producing side-impact beams:

    • Docol AHSS exhibits a pronounced yield strength increase of about 150 MPa or more after work-hardening and bake-hardening.
    • Docol AHSS exhibits a strain rate hardening effect. This effect corresponds to an increase of about 100 MPa at the high strain rates that are involved locally in a side crash.
    • Using alternative materials like aluminum can require up to three times the thickness of Docol AHSS in order to match its strength.

    Cost savings with Docol AHSS

    Here’s how you can lower your costs with Docol AHSS:

    • Use less material – thinner steel, same strength
    • Use cold forming instead of expensive, hot-stamped boron
    • Replace aluminum and other materials for better cost efficiency
    • Simplify production processes
    • Retain current production machinery
    • Recycle materials
    • Reduce overall cost of final product
    Docol in Rocker panels

    Rocker panels

    When Ford was searching for a new material for the rocker panels in its 2011 Ford Focus, they had a few objectives in mind: increase safety, reduce the thickness of the application and save weight.

    After the company contacted SSAB and discussed the possibility of using Docol 1400 MZE, the process began. Trials were conducted, production methods streamlined and prototypes tested. In the end, the rocker panel made from Docol 1400 MZE was an entire 30 percent lighter than the original, and because of the steel’s unique strength proved to be a stronger, safer design.


    Docol in seating

    Seating

    The seats represent 5-7 % of the total weight of a mid-sized car. They also play an important role in case of an accident to help passengers remain securely and safely in place. Being such a heavy item in the car, the potential for reducing weight is obvious. Advanced high-strength steel can benefit quite a few parts in a seat.


    Read article: Industry spotlight Steel in automotive seating

    Industry spotlight Steel in automotive seating

    The evolution of automotive seating

    Automotive seating has evolved radically over the past four decades. The first focus on seat design from a safety perspective really came about in the 1970s, at the time of the launch of cars such as the first VW Golf. At that time, millions of people were dying every year in road traffic accidents all over the world and in France alone during the 1970s the annual death toll was around 14,000. The industry then shifted its focus on how to best protect the vehicle’s occupants.

    Then during the 1980s, while safety was still a key concern, the focus shifted somewhat to comfort and features, with the addition of many new options such as powered and heated seats. Now in the 21st century, as environmental concerns have become so critical in all areas of life, the focus in terms of automotive seating manufacturing has shifted to focus on weight, materials, and sustainability.

    Weight a key issue in modern design

    “Weight is a key issue in modern automotive design because the less weight in the vehicle, the fewer emissions, and there are ever-more stringent conditions being placed on car manufacturers in terms of how environmentally friendly their vehicles are,” explains Philippe Aumont, Chief Technologies Officer at Faurecia’s R&D center in Étampes, just south of Paris. “What has changed now is that in order to be able to maintain or improve safety whilst reducing weight, we have had to deep dive into basic technology and science which weren’t previously taken into consideration when designing automotive seating,” he adds.

    Previously, the design of a car seat was approached from a more empirical standpoint. “Nobody considered the composition of the materials such as the steel that was used. Nobody gave a second thought to the different phases of the metal – steel was steel, and if it could be bent or welded OK, then that was fine,” Aumont says.

    “But now, with our focus on optimized weight and cost, we have had to delve into science, and with the help of suppliers, research partners, and our own R&D experts, we’re on a totally different level,” says Aumont. “The business is more scientific than it ever has been and that’s the biggest change the industry has ever seen, one which is inspiring a great deal of excitement and enthusiasm,” he adds.

    Safety and science meet in the seat

    When creating a seat, the first thing to consider is to position the structure where the architecture of the car needs it to be. “Our customer will give us what is known as the ‘H-Point’ for the seat, which refers to where the occupant’s hips should sit, and from this reference point, we can position the various mechanisms,” explains Aumont. These are then linked together with a frame that holds the seat correctly and the occupant in a safe and comfortable position.

    “Our second consideration is keeping the occupant in the right state during an emergency scenario in which the seat will need to absorb enough energy to protect the occupant from injury,” says Carey Dilliott, Director Generic Frames & Advanced Frames Engineering at Faurecia R&D. The first issue to be considered is in the case of frontal impact. “Here, the seat stops the occupant from continuing forward and must prevent ‘submarining’, whereby the occupant slides forward underneath their seatbelt. This is ensured by the front part of the seat cushion,” Dilliott explains.

    Rear impact is the most difficult emergency scenario to combat through the automotive seat. This kind of impact is most common at low speeds, and the seat needs to behave in an elastic way to avoid whiplash. At medium speeds, the backrest offers the main protection and a limited dynamic deflection helps to protect the people in back. At high speed, it’s about protecting the occupant: “We spend a lot of time researching the deformation properties of the steels we use because the controlled deformation of the material is what really helps protect the occupants in these cases,” says Dilliott. For protection against lateral or side impact, the solutions included in each car depend on the manufacturer. Some choose to use the car structure, and others the seat.

    Safety regulations also play a major role in adding to the weight of the seat, but crash safety specifications would appear to be stabilizing now. “Between 1980 and 2010, cars were required to be safer every year,” says Dilliott. “This pushed the weight of seat frames from an average of around 10 kgs to 17 kgs (22 to 37 lbs), in parallel with the weight of the car. But it’s hard to see how much more improvement we could have made to safety in cars using this method before they’re no longer classified as cars and are considered as tanks instead!” he adds. A complete seat module weighs between 60-70 kgs (132-154 lbs) of a total weight of a modern midsize car of 1200 kg (2646 lbs).

    High technology places special demands on construction

    A car seat today is a complex system because many different technologies are involved in its construction. “We are dealing with companies such as SSAB in terms of steel structures, of course, but we are also working with forming and joining processes, plastics technologies, motors, foams, and any soft materials, all of which require different engineering expertise,” says Aumont. Faurecia also has to integrate electronics into its seats, and opened a new electronics lab at the Étampes site two years ago to meet the demand. “Our technological expertise is our competitive edge and we want to hold on to that position in terms of the technologies used in seating construction,” Aumont stresses.

    The materials used in automotive seating vary but they are mainly steel, with around 20 different micro-alloyed and high-strength steels used, although mild steels have now been replaced with composites. Faurecia is constantly looking at alternatives in order to always have the best combination of weight to cost.

    Aluminum is one material that has been considered for use in the manufacture of automotive seating for its lightness, although to provide strength comparable to that offered by steel, it needs to be fairly thick. But the major issue for aluminum is joining technology. “Welding steel to steel is relatively easy but successful hybrid joining is expensive which makes us tend to avoid having to join different materials,” says Joel Galmiche, Stamping Engineer Manager at Faurecia R&D.

    Another key issue for Faurecia to consider when choosing materials is global provisioning – the company needs to be sure that it can produce identical parts across the globe to serve its wide-reaching customer networks. “We need to be able to use the same material all over the world,” explains Galmiche. “If, say, Ford is making the same car in 15 different locations around the world, then we have to supply the same product to them wherever they are, without the need for any additional validation. That can be challenging in terms of sourcing certain materials, particularly in the US,” he explains.

    Sustainability at the forefront

    Sustainability is another important consideration for Faurecia. “That ‘new car smell’ that you can detect when you entered in a new vehicle came from the chemicals used in the car’s production, such as plastic covers in a seat,” says Aumont. “In the past, those odors and thus those chemical residues were ignored, but now we are looking at new kinds of foams and plastics with fewer volatile emissions, as part of a more sustainable approach to our business, with the aim of better protecting our employees and those in our environment, as well as our customers and end users,” he adds.

    The amount of freedom Faurecia has in terms of seat design varies from constructor to constructor. “In some cases, we are completely free with the design, and in others, we build to print using drawings supplied by the customer,” says Aumont. “But one thing is for sure – we are always the manufacturing arm of the car manufacturer, and in many cases, we’re the engineering arm, too. We have to be flexible and adapt our business model to that of the car manufacturers,” he adds.

    Collaboration and agility driving the industry forward

    To remain at the forefront of technological progress, Faurecia has a policy of working in close cooperation with materials manufacturers, and the collaboration goes both ways. “Sometimes, a steel manufacturer like SSAB might come to us with a concept for a new material, or we might have a project in mind that we’d like to develop using their steel,” Aumont explains.

    Faurecia is also very keen to participate in consortium projects, working on collaborative programs that bring together industry players with researchers and local authorities. “Our primary concern is moving the technology to the next level, and it’s often through programs such as these that advances are made. It gives us the opportunity to experiment with materials that aren’t yet at the mass production stage but that we might be using in the future,” explains Tudor Balan, who works part-time as a Senior Expert at Faurecia, and part-time as Associate Professor at the ENSAM French higher education establishment in the eastern city of Metz. “We are currently involved in two European projects looking at prototype steels, as ever seeking more strength for less thickness,” he adds.

    “Increased strength has taken priority over formability for a long time, and we are now very close to the limit of what we can work with, which is why we are examining these new kinds of steels,” says Galmiche. “We are also looking at heat-assisted forming solutions where currently, all forming is done at room temperature. Operating at a higher temperature would aid formability but as ever, the main issue is one of cost,” he explains.

    “I believe that in the future, we will use many more different materials to improve the construction of automotive seating,” says Aumont. “The challenge is joining them together, and I see strong development of new adhesive bonding technology. Moreover, as engine technology improves and emissions are reduced, this will offer better performance so the pressure on weight reduction will decline,” he adds, before concluding, “But in terms of R&D, the future will be in virtual development. We are aiming to be able to develop everything without a prototype or at least to be able to sell the first prototype, as the first product, as the aviation industry does. Flexible, advanced, and high-tech development in close cooperation with materials suppliers is the key to moving forward for an increasingly technical and scientific industry such as ours.”

    Sill reinforcements

    Wagon Automotive produces complex parts for the automotive industry. The company uses Docol 1200 MZE electrogalvanized steel in its sill reinforcements and works with very strict and tight radii. As with other safety components of a vehicle body, the sills need to be lightweight, able to absorb impact energy and have high safety for both occupant and pedestrian.


    Reduction in weight and improved cost-efficiency

    Watch the video to learn more about this application.

    We produce grades to automotive OEM standards


    Body-in-white

    Steel for cars

    Docol high-strength steel, a strong and light AHSS and UHSS, helps vehicle designers and manufacturers reduce CO₂ emissions, lower costs and ensure safety.