Making Stronger Steel As Light As Aluminum


Ford Fiesta body-in-white

The world's largest steel maker, ArcelorMital, says it has come up with a new kind of steel that the world has never seen before. Thanks to nanotechnology, the company says automakers can now match the weight of aluminum cars, but do it in steel at far lower cost.

It can take 188 pounds out of the body-in-white of a car... but total weight savings could be even bigger.
Specifically, ArcelorMital says it can take 188 pounds out of the body-in-white of a car. The body-in-white, or BIW, refers to the basic structure of a car, including the doors, hood and deck lid. That's a big number. By taking so much weight out of the structure, other components such as the powertrain, drivetrain, brakes, etc. can be downsized as well. In other words, the total weight savings could be even bigger.

ArcelorMital is already showing this new kind of steel to automakers. It isn't yet ready to publicly divulge any of the technical aspects of the steel or how it's using nanotechnology to make it. The company says we're still two to three years away before we get those kinds of details. And that's about the time we'll see this steel show up in production. No word yet on which car company may be the first to use it, but the rumor on the street is that Ford is all over this technology.

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John McElroyJohn McElroy is host of the TV program "Autoline Detroit" and daily web video "Autoline Daily". Every week he brings his unique insights as a Detroit insider to Autoblog readers.



The nano steel itself is not inherently lighter, but it's so strong that automakers can use thinner gauges and that's where part of the weight savings comes from. Another part of the weight savings comes from not having to use additional brackets, gussets or panels to strengthen the structure.

For example, A-pillars are becoming so big these days due to roof crush standards that they are actually becoming a safety hazard. The fat A-pillars can partially block your view to side traffic or pedestrians. But with this nano steel, A-pillars could be made much thinner with no sacrifice to structure or safety.

The nano steel does require a newer manufacturing technique called hot stamping.
Nor is this steel cheaper than other grades of steel. In fact, it's probably a little bit more expensive. But by eliminating all those brackets and extra panels, the total tooling cost of a car goes down, and that's where the costs savings comes from.

To get the maximum 188-pound reduction in the BIW, an automaker would have to design-in the nano steel's capabilities using a clean sheet approach. But ArcelorMittal says that some applications, especially cross-members, lend themselves to running changes on existing designs.

The nano steel does require a newer manufacturing technique called hot stamping. That's where automakers heat up the steel blanks that go into a stamping press to the point where they're literally glowing red. Then they feed the red hot blanks into a press and stamp them into body panels. Heating up the steel makes it much more pliable and enables it to be formed into more complex shapes. Actually, this is a fairly common process already in use today, used to form the high-strength steels that have been available for the last decade and a half. So, while the nano steel requires hot stamping, it's not as if automakers need to make a big investment in manufacturing technology.

Covitic aluminum somehow impregnates aluminum with carbon fiber.
It's very impressive to see the steel industry delve into new technology to keep its product relevant. Aluminum, magnesium and composites definitely pose a competitive threat to steel. But they're also considerably more expensive, are not as easily repaired in most body shops, and require considerably more energy to recycle. That's why they've not found widespread use in cars, or at least not as widespread as steel.

And yet, I've heard tantalizing whispers of the new breakthrough coming in aluminum. It's called covitic aluminum, where somehow they impregnate aluminum with carbon fiber. There, now you know about as much of it as I do.

I'm pretty sure we'll get some sort of announcement later this year about covitic aluminum. But for right now at least, this nano steel seems to be the latest word in materials technology.




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