"It's my job to prepare my best possible case, poke holes in my competitor's case, and convince the customer to use steel for this application." The speaker is J.P. McGuire, product applications engineer at U.S. Steel's Product Technology Automotive Group (PTAG) in Troy, MI. He's just run through an explanation of how he convinced one automaker to drop its plans to use an aluminum hood on a new vehicle. It involved showing that the calculations giving steel an 18-lb weight disadvantage were based on worst-case models, creating a detailed proposal based around an optimized design using newer steel grades, and convincing the OEM's purchasing department there would be a substantial cost savings despite the fact that these new steels are more costly on a per-pound basis.*
Although there is an array of new advanced high strength steels (AHSS), some vehicle manufacturers are stuck in an old paradigm. "Many of the models being used are outdated," says Aleksy Konieczny, metalforming specialist at PTAG. "They come from continuous-improvement hell, where the model that has been used for years is updated but not changed. Often, we have to create a new model that better utilizes the characteristics of the new steel grades, and has substantial benefits compared to the steel exemplified in the older model and aluminum." However, the PTAG team produces more than just optimized models. It creates detailed reports that contain the gauges and strengths used throughout the part, to-the-penny cost estimates, as well as a promise that the design can be produced to the customer's quality and durability standards using–as much as possible–the existing machinery and processes. "Not only do we come out significantly lighter than the customer originally expected from steel," says McGuire, "we have a definite cost advantage compared to aluminum." (As a former aluminum company employee, he has unique insight.) And, as often happens, a directive from management to substitute aluminum is met by a detailed analysis of why staying with steel is the better choice.