Ding~Dong! A parcel was left at the doorstep. It was a large box with an electric car drawn at the front, and it came with a card. Two words — POSCO and eAutopus — were written on the box, and the card read “e Autopos Unboxing”. Join us for the unboxing of POSCO’s integrated brand of sustainable automotive product & solution, “e Autopos”.

l Mission: Observing the Box

Before opening the box, let’s take a closer look from the outside. “e Autopos” written on the picture of an Electric Vehicle (EV) is POSCO’s integrated brand of eco-friendly automotive product solutions. The brand refers to POSCO’s steel and secondary battery material products used in EVs and Fuel Cell Electric Vehicles (FCEVs), and customized solution packages that can be applied to these products. e Autopos is a combination of the words eco-friendly and electrified AUTOmotive solution of POSco.

l Now for the Real Unboxing! eAutopus Car Body

The inside of the box reveals a car body that looks quite solid.

The car body consisting of eAutopos products is light and strong. To protect the environment, cars must be lighter because a heavier car needs more energy and emits more greenhouse gas. EVs are about 200kg heavier than conventional fuel engine vehicles because of the battery pack weight, so reducing weight is an essential task for EVs. However, making a car lighter isn’t as easy as it sounds. Developing a lightweight and strong body is important for the safety of the users because the vehicle body absorbs and distributes shocks in the event of an accident and also prevents battery damage.

Accordingly, POSCO developed PBC-EV (Posco Body Concept for Electric Vehicle), POSCO’s solution for EVs where Giga Steel is applied. Applying more than 45% of Giga Steel, PBC-EV achieved a weight reduction of about 30% compared to conventional fuel engine vehicles of the same size. Giga Steel is more than three times stronger than aluminum, which has recently been applied to automotive bodies and can withstand a weight of more than 100kg per 1mm².

The e Autopos automotive body solution includes many of POSCO’s advanced steel grades because the passenger and battery spaces should be designed to prevent deformation in case of an accident or a collision. Also, the traction motor space in the front, the trunk space in the rear, and the side space should be designed to absorb the collision force.

980XF is applied for the Front Side Member that absorbs shock at the front of the vehicle due to its excellent tensile strength^* and elongation^**. For the Side Sill Inner Reinf, which absorbs shock at the relatively narrower side area, 1180 TRIP product is applied because of its outstanding strength and elongation.

In the event of a collision, the shock is first absorbed in the front, rear, and sides. The remaining energy is then transferred to the passenger and the battery space inside the vehicle. Therefore, it is important to apply a steel product that prevents this. The strength of the steel applied here should be higher than that of the ones used in the areas that receive the shock directly.

The remaining energy after the initial absorption in the Front Side Member is transferred to the Extension Member Front Side Outer Rear, and here comes another important task: this part must sustain the impact without any deformation. Accordingly, since the shape is relatively complicated, a 1.5 GPa-class 1500HPF product was applied to secure formability and collision resistance at the same time. 1500HPF is formed by heating steel plates at a high temperature of 900°C and then cooled down and shaped in a mold.

The Dash Cross Member Outer and Seat Cross Member, which serves to protect passengers by suppressing automotive deformation in the event of a collision, employs 1500MART. 1500MART is a high tensile strength product of 1500MPa and maximizes the prevention of automotive body deformation.

l Eco-friendly Car Chassis Made Complete with eAutopus

▲ The Chassis of an EV

Now let’s take a closer look at the “chassis” which is in charge of driving functions! Connected to the bottom of the car body, the role of the chassis is to enable driving and absorb shock. The chassis is composed of Suspension and Hub Bearing, the essential machine parts required to run a vehicle, and Suspension Spring and Shock Absorber to absorb the shock from the road.

The Giga Steel introduced in the e Autopos automotive body solution is also applied to the suspension. POSCO developed a lighter, longer-lasting suspension with Giga Steel. POSCO Bearing Steel is used for hub bearings that are mounted on automotive wheels to help the wheels rotate. Since POSCO Bearing Steel is used for wheels that are directly connected to passenger safety, its quality is strictly managed and it features high resistance to abrasion, cracking, and deformation.

Tires with e Autopos solution are strong to puncture. This is possible because of POSCO Tire Cord Steel! The Tire Cord Steel supports the weight of the vehicle, maintains the shape of the tire, and extends the life of the tire. POSCO’s Tire Cord Steel is made of high-strength carbon, has excellent machinability and high strength, so it is lightweight and features excellent driving stability.

POSCO’s Spring Steel is applied to the Suspension Spring, which is responsible to secure comfortable rides by minimizing the shock or vibration transmitted from the road. As for the Shock Absorber, POSCO’s Carbon Steel for Machine Structure is adopted. POSCO Spring Steel is stronger than conventional spring steel by more than 200 MPa, yet 15% lighter since the number of coils wound around is minimized, making it suitable for weight reduction. As such, e Autopos solution is applied to all parts of the eco-friendly automotive chassis!

The 2018 North American International Auto Show brought the biggest names in the auto industry together for a show and tell. (Source: News Atlas)

Continuing on what we saw during the past few years, the focus this year again was on improving safety, performance and design, all at the lightest weight possible for fuel economy. While there have been debates in the past about the best lightweight material, there was a clear winner at this year’s NAIAS. Almost every car, including the 2018 Car of the Year, was clad in advanced high-strength steel (AHHS) and significantly lighter than their predecessors.

Take a look at some of this year’s steel-clad cars.

SEE ALSO: 5 Reasons Why AHSS Tops the Market for Lightweight Auto Materials

2018 Car of the Year: Honda Accord

The 2018 Honda Accord took home the prestigious title of Car of the Year due to its lightweight and improved strength and performance. The 2018 model contains 29 percent ultra-high-strength steel (UHSS) in its chassis and 54.2 percent high strength steel (HSS). With these applications, the Honda Accord achieved a weight reduction of 110 to 176 pounds while improving its body torsional rigidity by 32 percent and its bending rigidity by 24 percent.

2019 Chevy Silverado

The all-new Chevy Silverado comes armed with plenty of steel. One of the features that contribute to its improved safety is the bed floor made of roll-formed HSS. Also, 80 percent of its fully-boxed steel frame is made of HSS and AHSS forms the Silverado’s safety cage. Overall, the new model is taller and 7 inches wider than before. Nevertheless, the all-new Silverado is 450 pounds lighter with a 10 percent increase in torsional rigidity than the previous model.

2019 Dodge Ram 1500

The 2019 Dodge Ram 1500 is another steel-intensive vehicle revealed at NAIAS. About 98 percent of this year’s model is made from HSS, and is the lightest, longest and most efficient frame in the half-ton truck segment. The wheelbase and crew cab is 4 inches longer than the previous model. The Dodge Ram 1500 also has several new safety features. The unique front-splayed frame rail technology, frame-mounted HSS tire blockers and fully-boxed side rails allow the car to absorb more energy in case of impact and minimize structural damage.

2019 Kia Forte

The 2019 Kia Forte is taller, wider and longer than before with 54 percent of its chassis made of AHSS. It also has a 16 percent stiffer body-in-white and the new seat frames are lighter yet stronger as Kia has its eyes on top ratings from the Insurance Institute for Highway Safety (IIHS) for the second consecutive year. The lighter and stronger vehicle will consume about 9 to 20 percent less fuel as well as drop noise levels by 5 decibels.

Why the Steel Overload?

As mentioned above, the latest cars are steel-intensive and automakers increasing the amount of HSS, UHSS and AHSS in their mix of materials. Of course, the main reason for this is steel’s innate properties that make it the ideal solution for automakers looking to cut back on weight and still satisfy safety standards. However, automakers also learned a good lesson from automakers who chose another popular lightweight material – aluminum.

SEE ALSO: Materials Matter: Why Steel Beats Aluminum in the Sustainability Debate

Back in 2014, Ford released its F-150 with an all-aluminum body. The move was bold and the cars sold fast as it was a whole 700 pounds lighter than previous models. Consumers got to drive away with a drastically improved fuel economy, but it didn’t take long for them to realize the big, expensive problem with aluminum bodies: repairs.

The 2015 Ford F-150 has an all-aluminum body. (Source: Hennessey Performance)

Although steel and aluminum are similar in terms of its lightweight properties, aluminum reacts differently than steel under heat. Aluminum does not have metal memory, while steel does, making it hard to reshape and repair following an accident. Welding aluminum also takes much more skill and precision than steel, and there are few repair shops that are equipped to handle aluminum. As a result, drivers not only have a hard time finding repair shops for their aluminum cars, they have to pay a hefty price for repairs compared to repairs for steel cars. For example, Jalopnik reported one of the first cases of the F-150 repairs back in 2015 cost USD 17,000 and a month-long repair time.

Of course, this was a rare case highlighting the steep learning curve of repairing aluminum vehicles, but it also highlights the fact that steel is still the norm when it comes to automotive materials, and judging from the 2018 NAIAS, it’s going to stay that way for quite some time.

Cover photo courtesy of Honda of Lincoln.