By Stuart Burns
There is a war being waged in the automotive sector between competing materials and the loser appears to be the traditional steel producers. According to a Reuters article, the use of advanced high-strength steels has doubled in North America between 2005 and 2009, reaching 150 pounds per vehicle as carmakers seek ever-thinner and lighter materials to reduce car weights. The world's third-biggest carmaker, Volkswagen (VLKAF.PK), is said to have used thinner sheets of high-strength steel -- which is up to six times as strong as conventional steel -- to help reduce the weight of its latest Golf model by about 100 kilograms (220 pounds).
Using higher-strength steels allows carmakers to use thinner gauges to achieve structural strength at lower cost than the use of aluminum. Cutting one pound of body weight with advanced steels costs about 50 cents, while using aluminum costs four times as much. Nevertheless, as a measure of how much the low-hanging fruit may already have been plucked while the use has doubled between 2005 and 2009, the article states, it could be 2025 before it doubles again to 365 pounds, suggesting the rate of uptake is linear rather than exponential. Meanwhile, aluminum use continues to rise. Originally used more in engine blocks, transmissions, heat exchangers and wheels, high-end cars are being produced with all-aluminum bodies and lower-value models are incorporating the lighter metal in doors, bonnets and wings.
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Steel has the most to lose. Apparently, one in every eight tons of steel produced is consumed in the automotive industry, compared to just 8% of aluminum. But to achieve significant further weight gains, greater use of aluminum is likely to be required. Dick Schultz, managing director of consultancy Ducker Worldwide in Michigan, is quoted as saying, "In North America where we have to double our fuel economy by 2025, you have to take drastic measures. If you really want to save a lot of weight, you have to use aluminum." He added: "There’s more of the new steel used in Europe today than in North America, and Europe is probably more typical of what could happen in the rest of the world."
Ducker forecasts that global aluminum use in passenger vehicles is likely to surge 65% to 28-30 billion lbs (12.7-13.6 million metric tons) by 2020 from about 17-18 billion lbs in 2009. Meanwhile, the adoption of high-strength steel is also eating into the tonnage of conventional steel across the automotive industry; for every pound of high-strength steel used, two pounds of conventional steel are lost. For now, engine makers are working just as hard to improve the economy, yet maintain the performance of the internal combustion engine. Good progress has already been made in the U.S. as CAFE rules drive innovation in the same way high fuel prices have done in Europe. The challenge for the electric car to compete on economy is just getting harder and harder.