Continued from Part One.
MetalMiner recently had the chance to sit down with Ron Krupitzer, vice president, automotive market for the Steel Market Development Institute. Having covered the aluminum industry’s involvement in lightweighting, we wanted to get the steel perspective on the issue.
MetalMiner: From where we left off with the last question, it’s clear that much of the debate between steel and aluminum as the material of choice for cars centers on cost. At a time when OEMs are trying to protect their margins, to what degree is material cost a driver for these buyers when considering steel vs. aluminum?
Ron Krupitzer: When we make advanced high-strength steels (AHSS), they are going to cost more per ton, more per pound — they are a premium product. But when a buyer goes out to source steel for a given part, they’re going to have to buy less steel. We’re saving 25 or 30 percent of the actual weight purchased. In the end, you won’t find any combination of materials that can save the same amount of weight at about the same cost that you had before in the traditional parts that you’re trying to re-engineer. Steel Market Development Institute’s 2011 report FutureSteelVehicle showed that we can design a vehicle with a hybrid platform or a fully electric vehicle that, even [including] the battery pack, we can save weight using steel and reduce emissions and fuel consumption to the point where it’s competitive with any vehicle in the world.
MM: From a corporate social responsibility (CSR) standpoint, how important is it to consider the lifecycle costs of a mostly-aluminum vehicle versus a mostly-steel vehicle?
RK: The steel industry is spending a lot more time looking at sustainability, life cycle and the environmental impact of our materials overall. First, there’s emissions impact — that’s important. Steel is the lowest energy-requiring structural material for cars, and therefore requires the lowest emissions to make a given mass unit of steel compared to aluminum, magnesium or even carbon fiber. It all relates to the fact that steel comes from iron oxide. Iron oxide is more than willing to give up its iron as a metal from the oxide, and the steelmaking process requires very little energy on a relative basis compared to other processes. Aluminum oxide or bauxite requires a lot more, and magnesium and the processing of carbon fiber require tremendous amounts of energy to manufacture those products. AHSS vehicle will weigh less than a traditional vehicle, and burn less fuel in its driving cycle.
Steel is fully recyclable at the end of life, and is the material that’s most targeted for recycling when vehicles are dismantled to their respective metal industries. Today, the steel that comes back from an automobile can go into any steel product. There aren’t that many materials in a vehicle (steel represents about 60% of every vehicle), but however much aluminum does come back is mainly in castings — aluminum blocks, aluminum heads — which is not the right chemistry to go back into body sheet or aluminum structural parts that are all being proposed now. All the new material that’s being looked at for mass reduction in aluminum parts has to come from bauxite — from high-energy production — so it’s something to be looked at when trying to satisfy the mass reduction [targets].
The interview concludes in Part Three.