TOKYO -- Nippon Steel & Sumitomo Metal has developed an automotive steel sheet that is 20-30% lighter and 25% stronger than the toughest high-tensile steel now on the market, hoping to help carmakers build more fuel-efficient, safer vehicles.
The company is conducting verification tests and will start marketing the product around 2020 for use in vehicle frames, chassis and other components.
Currently, the highest grade of cold-rolled steel offered by major steelmakers has a strength of 1,180 megapascals. Nippon Steel's new, lighter material has a strength of 1,470 megapascals.
By improving the heat treatment process and adding alloy elements, Nippon Steel improved both strength and ease of rolling. The material is resistant to cracks from the stamping process.
The company hopes to keep the price flat with current top-of-the-line offerings.
The material is not as light as aluminum alloy or plastic reinforced with carbon fiber. But its price is only a third to half that of aluminum -- with processing costs factored in -- and about 1/20 that of carbon-fiber plastic.
Automakers are scrambling to meet increasingly tight fuel-economy regulations worldwide by employing lighter materials in vehicles. Nippon Steel thinks its new product fits the bill -- at a reasonable price.