Advanced steel grades date back to the 1960s and early 1970s during some of the first oil crises in the United States, says Blake Zuidema, director of automotive product applications for ArcelorMittal's global research and development center in East Chicago, Ind.
Many of the basic AHSS concepts were present for decades but were used for heavier-gauge materials such as forgings, large castings and aircraft landing gear, Zuidema explains.
By the late 1970s some automakers began looking at ways to incorporate dual-phase steels into vehicles, including General Motors Corp., says Ron Krupitzer, vice president of automotive applications for the American Iron and Steel Institute. Research on the materials seemed promising, but it wasn't clear how to mass produce the steel in the mills. Eventually, the industry figured out that it could integrate the cooling characteristics of traditional steelmaking processes, such as continuous annealing or galvanizing lines, to make uniform properties of the dual-phase materials, Krupitzer says.
Volvo was one of the first automakers to adopt AHSS for its vehicles in the 1990s, Krupitzer says. In 1994, a consortium of 35 sheet steel producers from 18 countries created the Ultra Light Steel Auto Body project.
The steelmakers wanted to create a lightweight steel auto body that would meet various safety and performance targets.
A year later, the consortium demonstrated that a midsize sedan could achieve a weight savings of up to 36% using AHSS technology. By 1998, the consortium had developed a complete ultra-light steel auto body. Additional projects followed through the years leading to the Future Steel Vehicle program in 2007. Led by the World Steel Association's automotive group World Auto Steel, the Future Steel Vehicle program developed AHSS body structures for four proposed 2015 to 2020 model-year hybrid and fuel-cell powered vehicles. World Auto Steel expects to introduce 20 new AHSS material grades during this timeframe.
AHSS also shows some potential for use outside the auto industry. There could be a market for AHSS in the agricultural industry to make trailers or combines lighter to reduce soil compaction, ArcelorMittal's Zuidema says.
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