Dr. Axel GrÃ¼eklee headed up the ThyssenKrupp InCar plus development project that came up with some 40 innovations to make vehicles lighter, less expensive, better-performing, and/or more sustainable. He said they benchmarked the state of the art in areas ranging from body to steering to powertrain, then worked to best it.
While steel wheels have tended to be somewhat style-challenged, ThyssenKrupp has come up with a way to make steel wheels that are 20% lighter than aluminum by having the styled portion inserted into a standard rim.
Iâll admit that when I heard that ThyssenKrupp (thyssenkrupp.com) had conducted a project called âInCar plus,â I figured that it had something to do with steel. Given that there were more than 40 projects involved, I figured that they really did a lot of work on and with steel.
And so when I meet with Dr. Axel GrÃ¼eklee, InCar plus project manager, I assumedâincorrectlyâthat he is going to show me an assortment of steel coupon samples or maybe stamped parts. And not much else.
âThis was the biggest R&D project in our company for the auto industry,â he says. âIt included participation of eight companies in our group.â
Yes, they develop steel. Yes, InCar plus includes steel-related developments. But know that there is a whole lot more. Did you know that ThyssenKrupp produces assembled camshafts, cylinder head modules with integrated camshafts, crankshafts, steering and damping systems, springs and stabilizers, and assembled axle modules?
Youâve heard of Bilsten shocks? Theyâre from ThyssenKrupp Bilsten GmbH.
Yes, more than steel.
GrÃ¼eklee explains that for the projects they undertook, the objective was to better the existing state of the art in one or more ways. That is, they wanted the developments to be lighter, more cost competitive, higher performing, or more sustainable than the best out there.
Which means that the developers didnât limit themselves to a steel portfolio, although some steel advances truly make for big advantages.
They developed a steering column. Through the use of carbon-fiber reinforced plastic for components they were able to reduce the weight of some components by as much as 60% and the overall weight of the assembly by 25%.
There is an adjustable cam element for variable valve lift systems. GrÃ¼eklee notes that this is something that is ordinarily produce with steel, but theyâve created a hybrid system that utilizes both steel and plastic. As a result, there is a weight save of 30%. âDue to the lower weight, there can be cam lobe switching at higher rotational speeds. This can result in an additional 5% fuel reduction because of the ability to shift more quickly.â
There is a steel that theyâve developedâbut this material for various exterior body applications, named LITECORâis actually a steel-polymer sandwich. One example is a sheet that has a total thickness of 1 mm, with there being 0.2-mm sheets of steel on either side of a 0.6-mm plastic (a polyethylene polyamide material). GrÃ¼eklee says there are several advantages of this material, which can be a weight save on the order of 40% compared with conventional steel. For one thing, he says that it is essentially the same weight per area as aluminum, but is less expensive. For another, it is easier to attach to other steel components than aluminum is because there isnât the issue of potential galvanic corrosion, so fasteners, spot welding or bonding can be readily used. And the forming can be performed in the dies that are ordinarily used. The gauge of the material can be calibrated to meet application requirements (e.g., a hoodâs material is different than a roofâs).
GrÃ¼eklee notes, âI am quite sure if you built a pickup truck with hot formingââThyssenKrupp has extensive expertise in this process for ultrahigh-strength steel processingââand sandwich material, youâve have nearly the same weight but a better cost situation.â Heâs referring, of course, to a certain aluminum-intensive pickup.
âNobody wants these steel wheels because they donât look nice,â GrÃ¼eklee says, pointing to some steel wheels that are rather style challenged. Consequently, the aluminum wheel has pretty much become the standard. So what theyâve done is to create a wheel that uses a conventional steel rim and a stylized wheel disc that can be welded in place. While the wheel doesnât look precisely like a machined aluminum component, it is far more attractive than what has been the case for steel wheels. And there is the not insignificant fact that where the aluminum wheel weighs 10 kg, the steel wheel comes in at 8 kg.Â