Most steelmakers are struggling financially this year as they grapple with foreign competitors, the effects of a strong dollar and fading U.S. Big Three production volumes, but when they talk about tanking, it's good news. That's because steelmakers are hoping to steal back some of the fuel tank applications they've been losing to plastic over the past 10 years or so.
Steel industry sources acknowledge that most vehicles produced in North America today have plastic tanks, and they agree that near-term trends favor further growth for plastics. In fact, a recent technical paper from the American Iron and Steel Institute (AISI) predicts plastics' share of the North American fuel tank market will likely rise from 58% in 2000 to 80% in 2004. But longer term, steelmakers say, they'll be able to exploit environmental and cost issues to win back a larger share of the fuel tank business.
They say they can deliver steel tanks in the complex shapes that automakers want — just like the plastics folks — and that's key. New-style fuel tanks may look a little strange, but they provide maximum fuel holding capacity in a minimum amount of space.
An engineering study sponsored by the steel industry released earlier this year shows steel fuel tanks can meet design flexibility, volume capacity and weight requirements for complex, saddle-shaped fuel tanks while providing the inherent impermeability favored for meeting new, stringent evaporative emissions standards.
Those emissions standards — which limit the amount of fuel vapors that can seep out of a vehicle's fuel system — have stalled plastic fuel tank growth in the past, because plastic is inherently more porous than steel.
New fabricating methods such as hydroforming, special welding techniques and other technologies that allow more design freedom are creating new opportunities for steel tanks. However, environmental issues are considered more important to steel's fuel tank initiative. Steelmakers raise concerns about the recycling industry's readiness to reprocess gas-soaked plastic fuel tanks in scrapped vehicles. Plus, stricter evaporative emissions standards are due in the '04 model year.
Peter Mould, program manager for the AISI's Strategic Alliance for Steel Fuel Tanks, argues that the plastics industry is without a cost-effective solution to the permeability issues facing its fuel tanks. He points out that there is only one gas-powered vehicle that currently meets the California Air Resources Board stringent PZEV (partial zero emission vehicle) standards “and that's theSentra, which has a steel fuel tank.”
However, plastics suppliers beg to differ. Sources within the plastics industry and at independent fuel system suppliers argue that today's plastic fuel tanks incorporate new types of barrier layers that prevent tiny amounts of vapor from seeping through the plastic tank walls, and have enabled plastic tanks to jump over every emissions hurdle thrown at them so far. These sources also argue that fittings and connection points on the tanks, where tubes run in and out, are the most crucial emission areas in the future. In these areas, steel has no advantage.
Nevertheless, Mr. Mould says there are indications that the Audi A8,Beetle, Jetta, and Mercedes S-Class and A-Class are preparing to switch back to steel from plastics. “A lot of the things that moved fuel tanks away from steel were environmental,” Mr. Mould says. “What was harmful to us in the first place and beneficial to plastics, now is becoming harmful to plastics and helping us. It's an ironic situation.”
Ironic, and a bit testy. At the auto industry confab in Traverse City last month, the American Plastics Council made a point of passing out 1-gallon plastic gas cans at its booth. One might construe this as a gimmick by the plastics industry to thumb their noses at the steel folks, but officially, APC executives say they were trying to make the point that plastics save weight and improve fuel economy.
Aside from fuel tanks, the story for steel hasn't changed much in recent years. It's continuing to challenge the perception — if it still exists — that vehicles soon will be totally comprised of alternative materials, and carry on marketing and educating automakers on new uses for advanced steels.
Despite aggressive marketing efforts by rival materials and the constant push by automakers to reduce weight, steel has managed to roll with the punches for decades. Thanks mostly to the popularity of steel-intensive pickup trucks, sport/utility vehicles and minivans, the use of steel in the typical North American vehicle rose almost 8% from 1990 to 2000. Only in the past year or two have competitive materials managed to reverse steel's steady upward progress in the number of pounds per vehicle it claims. The existing and new applications for steel in 2002 add up to 1,773 lbs. (804 kg) of steel on the average North American vehicle compared with 1,781 lbs. (808 kg) in 2001, according to forecasts. Compare that with just 1,660 lbs. (753 kg) of steel used per vehicle in 1990.
“Although the market trends have not been favoring steel in recent years, there are now a lot of opportunities in front of us. And a lot of challenges also,” says AISI's Mr. Mould. “We feel we can capitalize on opportunities, and we're excited about what we're doing.”
Rightfully so. Revolutionary concepts such as tailor welded blanks and hydroforming are making steel viable for applications that many thought only a few years ago would've been switching to aluminum or plastic by now. The all-new '02 Dodge Ram, for instance, uses hydro-formed tubular steel for its engine compartment space frame — a first for North America, reports the publication American Metal Market. The conventional structures are made of stamped steel. But with hydroforming, DaimlerChrysler Corp. is able to reduce weight, consolidate parts and better customize the front-end design.
The Ram features another steel first, AMM reports: dash panels from tailored blanks, and the first high-volume use by the automaker of hydroformed tubular steel frames. The forthcoming '03 Dodge Durango reportedly will feature steel in many advanced forms as well.
Another key vehicle for the steel industry isCorp.'s '03 Hummer H2. Unlike the aluminum-bodied H1, the higher-volume H2 will be comprised of steel. “The fact that steel is GM's choice for the H2 body is a significant victory for the steel industry, because the Hummer line has been for years held up by the aluminum industry as an important example of what can be accomplished with aluminum sheet,” writes AISI Advanced Materials Manager Marcel van Schaik in an AISI newsletter.
Cadillac's '03 CTS features inner door panels made from tailor-welded blanks, as does the '02 Jeep Liberty. Even vehicles touted for their composite parts —Thunderbird and Saturn Vue — feature important steel applications. High-strength steel is used for the Thunderbird's cross-car beams behind the rear seats, AMM says. The Vue uses high-strength steel for some closure panels and cage-frames.